Document and Entity Information (USD $)	12 Months Ended
Document and Entity Information (USD $)	Jun. 30, 2013	Aug. 20, 2013	Dec. 31, 2012
Document and Entity Information
Entity Registrant Name	IMMUNOGEN INC
Entity Central Index Key	0000855654
Document Type	10-K
Document Period End Date	Jun. 30, 2013
Amendment Flag	false
Current Fiscal Year End Date	--06-30
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 1,070,664,433
Entity Common Stock, Shares Outstanding		85,109,108
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	FY

CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012
ASSETS
Cash and cash equivalents	$ 194,960	$ 160,938
Accounts receivable		129
Unbilled revenue	2,121	1,196
Inventory	703	1,288
Restricted cash	319	319
Prepaid and other current assets	2,581	2,400
Total current assets	200,684	166,270
Property and equipment, net of accumulated depreciation	10,783	11,633
Long-term restricted cash	1,912	2,231
Other assets	217	174
Total assets	213,596	180,308
LIABILITIES AND SHAREHOLDERS' EQUITY
Accounts payable	4,498	3,395
Accrued compensation	6,153	4,942
Other accrued liabilities	6,049	4,589
Current portion of deferred lease incentive	979	979
Current portion of deferred revenue	1,494	2,349
Total current liabilities	19,173	16,254
Deferred lease incentive, net of current portion	5,626	6,605
Deferred revenue, net of current portion	63,384	69,761
Other long-term liabilities	3,566	3,798
Total liabilities	91,749	96,418
Commitments and contingencies (Note H)
Shareholders' equity:
Preferred stock, $.01 par value; authorized 5,000 shares; no shares issued and outstanding
Common stock, $.01 par value; authorized 150,000 shares; issued and outstanding 84,725 and 77,759 shares as of June 30, 2013 and 2012, respectively	847	778
Additional paid-in capital	697,767	587,068
Accumulated deficit	(576,767)	(503,956)
Total shareholders' equity	121,847	83,890
Total liabilities and shareholders' equity	$ 213,596	$ 180,308

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012
CONSOLIDATED BALANCE SHEETS
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized shares	5,000	5,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares	150,000	150,000
Common stock, issued shares	84,725	77,759
Common stock, outstanding shares	84,725	77,759

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References+ Details

- Definition

Face amount or stated value per share of nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer); generally not indicative of the fair market value per share.

+ References+ Details

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2011
Revenues:
License and milestone fees	$ 24,227	$ 9,161	$ 6,393
Research and development support	7,873	4,517	7,256
Clinical materials revenue	2,843	2,679	5,656
Royalty revenue	592
Total revenues	35,535	16,357	19,305
Operating Expenses:
Research and development	87,073	69,192	63,453
General and administrative	21,471	20,422	16,040
Total operating expenses	108,544	89,614	79,493
Loss from operations	(73,009)	(73,257)	(60,188)
Investment income, net	126	66	218
Other income (expense), net	72	(128)	1,696
Net loss	(72,811)	(73,319)	(58,274)
Basic and diluted net loss per common share (in dollars per share)	$ (0.87)	$ (0.95)	$ (0.85)
Basic and diluted weighted average common shares outstanding (in shares)	84,063	76,814	68,919
Other Comprehensive Loss			(282)
Total Comprehensive Loss	$ (72,811)	$ (73,319)	$ (58,556)

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Balance at Jun. 30, 2010	$ 102,048	$ 679	$ 473,450	$ (372,363)	$ 282
Balance (in shares) at Jun. 30, 2010		67,931
Increase (Decrease) in Shareholders' Equity
Unrealized gains on marketable securities	(282)				(282)
Net loss	(58,274)			(58,274)
Stock options exercised	2,719	6	2,713
Stock options exercised (in shares)		550
Stock-based compensation expense	5,452		5,452
Issuance of common stock in a public offering, net of issuance costs	87,980	78	87,902
Issuance of common stock in a public offering, net of issuance costs (in shares)		7,800
Directors' deferred share unit compensation	326		326
Balance at Jun. 30, 2011	139,969	763	569,843	(430,637)
Balance (in shares) at Jun. 30, 2011		76,281
Increase (Decrease) in Shareholders' Equity
Net loss	(73,319)			(73,319)
Stock options exercised	6,988	14	6,974
Stock options exercised (in shares)		1,432
Stock-based compensation expense	9,938		9,938
Directors' deferred share units converted		1	(1)
Directors' deferred share units converted (in shares)		46
Directors' deferred share unit compensation	314		314
Balance at Jun. 30, 2012	83,890	778	587,068	(503,956)
Balance (in shares) at Jun. 30, 2012	77,759	77,759
Increase (Decrease) in Shareholders' Equity
Net loss	(72,811)			(72,811)
Stock options exercised	4,026	6	4,020
Stock options exercised (in shares)		666
Restricted stock award (in shares)		50
Stock-based compensation expense	12,400		12,400
Issuance of common stock in a public offering, net of issuance costs	93,991	63	93,928
Issuance of common stock in a public offering, net of issuance costs (in shares)		6,250
Directors' deferred share unit compensation	351		351
Balance at Jun. 30, 2013	$ 121,847	$ 847	$ 697,767	$ (576,767)
Balance (in shares) at Jun. 30, 2013	84,725	84,725

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2011
Cash flows from operating activities:
Net loss	$ (72,811)	$ (73,319)	$ (58,274)
Adjustments to reconcile net loss to net cash used for operating activities:
Depreciation and amortization	4,641	4,633	4,937
(Gain) Loss on sale/disposal of fixed assets	(21)	51	9
Gain on sale of marketable securities			(341)
(Gain) Loss on forward contracts	(197)	173	(189)
Stock and deferred share unit compensation	12,751	10,252	5,778
Deferred rent	(109)	(109)	(4)
Change in operating assets and liabilities:
Accounts receivable	129	4,539	(2,873)
Unbilled revenue	(925)	292	107
Inventory	585	(808)	762
Prepaid and other current assets	(181)	253	(1,038)
Restricted cash	319	1,018	574
Other assets	(43)	(16)	38
Accounts payable	1,103	182	149
Accrued compensation	1,211	219	522
Other accrued liabilities	481	133	(375)
Deferred revenue	(7,232)	18,219	42,229
Net cash used for operating activities	(60,299)	(34,288)	(7,989)
Cash flows from investing activities:
Proceeds from maturities or sales of marketable securities			1,201
Purchases of property and equipment, net	(3,770)	(2,908)	(2,029)
Proceeds (payments) from settlement of forward contracts	74	(60)	168
Net cash used for investing activities	(3,696)	(2,968)	(660)
Cash flows from financing activities:
Proceeds from stock options exercised	4,026	6,988	2,719
Proceeds from common stock issuance, net	93,991		87,980
Net cash provided by financing activities	98,017	6,988	90,699
Net change in cash and cash equivalents	34,022	(30,268)	82,050
Cash and cash equivalents, beginning of period	160,938	191,206	109,156
Cash and cash equivalents, end of period	$ 194,960	$ 160,938	$ 191,206

Nature of Business and Plan of Operations	12 Months Ended
Nature of Business and Plan of Operations	Jun. 30, 2013
Nature of Business and Plan of Operations
Nature of Business and Plan of Operations	A. Nature of Business and Plan of Operations ImmunoGen, Inc. (the Company) was incorporated in Massachusetts in 1981 and is focused on the development of antibody-based anticancer therapeutics. The Company has incurred operating losses and negative cash flows from operations since inception, incurred a net loss of approximately $72.8 million during the fiscal year ended June 30, 2013, and has an accumulated deficit of approximately $576.8 million as of June 30, 2013. The Company has primarily funded these losses through payments received from its collaborations and equity financings. To date, the Company has no product revenue and management expects operating losses to continue for the foreseeable future. At June 30, 2013, the Company had $195.0 million of cash and cash equivalents on hand. The Company may raise additional funds through equity or debt financings or generate revenues from collaborative partners through a combination of upfront license payments, milestone payments, royalty payments, research funding, and clinical material reimbursement. There can be no assurance that the Company will be able to obtain additional debt or equity financing or generate revenues from collaborative partners on terms acceptable to the Company or at all. The failure of the Company to obtain sufficient funds on acceptable terms when needed could have a material adverse effect on the Company's business, results of operations and financial condition and require the Company to defer or limit some or all of its research, development and/or clinical projects. The Company is subject to risks common to companies in the biotechnology industry including, but not limited to, the development by its competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, manufacturing and marketing limitations, collaboration arrangements, third-party reimbursements and compliance with governmental regulations.

Summary of Significant Accounting Policies

12 Months Ended

Jun. 30, 2013

Summary of Significant Accounting Policies

Summary of Significant Accounting Policies

B. Summary of Significant Accounting Policies

Principles of Consolidation

The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries, ImmunoGen Securities Corp., and ImmunoGen Europe Limited. All intercompany transactions and balances have been eliminated.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States (U.S.) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Subsequent Events

The Company has evaluated all events or transactions that occurred after June 30, 2013 up through the date the Company issued these financial statements. In August 2013, as part of its right-to-test agreement, Eli Lilly and Company took an exclusive development and commercialization license to a single target. The Company did not have any other material recognizable or unrecognizable subsequent events.

Revenue Recognition

The Company enters into licensing and development agreements with collaborative partners for the development of monoclonal antibody-based anticancer therapeutics. The terms of these agreements contain multiple deliverables which may include (i) licenses, or options to obtain licenses, to the Company's Targeted Antibody Payload, or TAP, technology, (ii) rights to future technological improvements, (iii) research activities to be performed on behalf of the collaborative partner, (iv) delivery of cytotoxic agents and (v) the manufacture of preclinical or clinical materials for the collaborative partner. Payments to the Company under these agreements may include upfront fees, option fees, exercise fees, payments for research activities, payments for the manufacture of preclinical or clinical materials, payments based upon the achievement of certain milestones and royalties on product sales. The Company follows the provisions of the Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) Topic 605-25, "Revenue Recognition—Multiple-Element Arrangements," and ASC Topic 605-28, "Revenue Recognition—Milestone Method," in accounting for these agreements. In order to account for these agreements, the Company must identify the deliverables included within the agreement and evaluate which deliverables represent separate units of accounting based on if certain criteria are met, including whether the delivered element has stand-alone value to the collaborator. The consideration received is allocated among the separate units of accounting, and the applicable revenue recognition criteria are applied to each of the separate units.

At June 30, 2013, the Company had the following two types of agreements with the parties identified below:

•

Development and commercialization licenses to use the Company's TAP technology and/or certain other intellectual property to develop compounds to a specified target antigen (referred to as development and commercialization licenses, as distinguished from the Company's right-to-test agreements described elsewhere):

- Amgen (three exclusive single-target licenses; one non-exclusive single-target license)
  
  Bayer HealthCare (one exclusive single-target license)
  
  Biotest (one exclusive single-target license)
  
  Novartis (one license to two related targets, one target on an exclusive basis and the second target on a non-exclusive basis)
  
  Roche, through its Genentech unit (five exclusive single-target licenses)
  
  Sanofi (exclusive license to multiple individual targets)
•

Option/research agreement for a defined period of time to secure development and commercialization licenses to use the Company's TAP technology to develop anticancer compounds to specified targets on established terms (referred to herein as right-to-test agreements):

- Sanofi
  
  Novartis
  
  Lilly

There are no performance, cancellation, termination or refund provisions in any of the arrangements that contain material financial consequences to the Company.

Development and Commercialization Licenses

The deliverables under a development and commercialization license agreement generally include the license to the Company's TAP technology with respect to a specified antigen target, and may also include deliverables related to rights to future technological improvements, research activities to be performed on behalf of the collaborative partner and the manufacture of preclinical or clinical materials for the collaborative partner.

Generally, development and commercialization licenses contain non-refundable terms for payments and, depending on the terms of the agreement, provide that the Company will (i) at the collaborator's request, provide research services at negotiated prices which are generally consistent with what other third parties would charge, (ii) at the collaborator's request, manufacture and provide to it preclinical and clinical materials or deliver cytotoxic agents at negotiated prices which are generally consistent with what other third parties would charge, (iii) earn payments upon the achievement of certain milestones and (iv) earn royalty payments, generally until the later of the last applicable patent expiration or 10 to 12 years after product launch. In the case of Kadcyla, however, the minimum royalty term is 10 years and the maximum royalty term is 12 years on a country-by-country basis. Royalty rates may vary over the royalty term depending on the Company's intellectual property rights. The Company may provide technical assistance and share any technology improvements with its collaborators during the term of the collaboration agreements. The Company does not directly control when or whether any collaborator will request research or manufacturing services, achieve milestones or become liable for royalty payments. As a result, the Company cannot predict when or if it will recognize revenues in connection with any of the foregoing.

In determining the units of accounting, management evaluates whether the license has stand-alone value from the undelivered elements to the collaborative partner based on the consideration of the relevant facts and circumstances for each arrangement. Factors considered in this determination include the research capabilities of the partner and the availability of TAP technology research expertise in the general marketplace. If the Company concludes that the license has stand alone value and therefore will be accounted for as a separate unit of accounting, the Company then determines the estimated selling prices of the license and all other units of accounting based on market conditions, similar arrangements entered into by third parties, and entity-specific factors such as the terms of the Company's previous collaborative agreements, recent preclinical and clinical testing results of therapeutic products that use the Company's TAP technology, the Company's pricing practices and pricing objectives, the likelihood that technological improvements will be made, the likelihood that technological improvements made will be used by the Company's collaborators and the nature of the research services to be performed on behalf of its collaborators and market rates for similar services.

Upfront payments on development and commercialization licenses are deferred if facts and circumstances dictate that the license does not have stand-alone value. Prior to the adoption of Accounting Standards Update (ASU) No. 2009-13, "Revenue Arrangements with Multiple Deliverables" on July 1, 2010, the Company determined that its licenses lacked stand-alone value and were combined with other elements of the arrangement and any amounts associated with the license were deferred and amortized over a certain period, which the Company refers to as the Company's period of substantial involvement. The determination of the length of the period over which to defer revenue is subject to judgment and estimation and can have an impact on the amount of revenue recognized in a given period. Historically the Company's involvement with the development of a collaborator's product candidate has been significant at the early stages of development, and lessens as it progresses into clinical trials. Also, as a drug candidate gets closer to commencing pivotal testing the Company's collaborators have sought an alternative site to manufacture their products, as the Company's facility does not produce pivotal or commercial drug product. Accordingly, the Company generally estimates this period of substantial involvement to begin at the inception of the collaboration agreement and conclude at the end of non-pivotal Phase II testing. The Company believes this period of substantial involvement is, depending on the nature of the license, on average six and one-half years. Quarterly, the Company reassesses its periods of substantial involvement over which the Company amortizes its upfront license fees and makes adjustments as appropriate. In the event a collaborator elects to discontinue development of a specific product candidate under a development and commercialization license, but retains its right to use the Company's technology to develop an alternative product candidate to the same target or a target substitute, the Company would cease amortization of any remaining portion of the upfront fee until there is substantial preclinical activity on another product candidate and its remaining period of substantial involvement can be estimated. In the event that a development and commercialization license were to be terminated, the Company would recognize as revenue any portion of the upfront fee that had not previously been recorded as revenue, but was classified as deferred revenue, at the date of such termination.

Subsequent to the adoption of ASU No. 2009-13, the Company determined that its research licenses lack stand-alone value and are considered for aggregation with the other elements of the arrangement and accounted for as one unit of accounting.

Upfront payments on development and commercialization licenses may be recognized upon delivery of the license if facts and circumstances dictate that the license has stand-alone value from the undelivered elements, which generally include rights to future technological improvements, research services, delivery of cytotoxic agents and the manufacture of preclinical and clinical materials.

The Company recognizes revenue related to research services that represent separate units of accounting as they are performed, as long as there is persuasive evidence of an arrangement, the fee is fixed or determinable, and collection of the related receivable is probable. The Company recognizes revenue related to the rights to future technological improvements over the estimated term of the applicable license.

The Company may also provide cytotoxic agents to its collaborators or produce preclinical and clinical materials at negotiated prices which are generally consistent with what other third parties would charge. The Company recognizes revenue on cytotoxic agents and on preclinical and clinical materials when the materials have passed all quality testing required for collaborator acceptance and title and risk of loss have transferred to the collaborator. Arrangement consideration allocated to the manufacture of preclinical and clinical materials in a multiple-deliverable arrangement is below the Company's full cost, and the Company's full cost is not expected to ever be below its contract selling prices for its existing collaborations. During the fiscal years ended June 30, 2013, 2012 and 2011, the difference between the Company's full cost to manufacture preclinical and clinical materials on behalf of its collaborators as compared to total amounts received from collaborators for the manufacture of preclinical and clinical materials was $755,000, $85,000 and $1.3 million, respectively. The majority of the Company's costs to produce these preclinical and clinical materials are fixed and then allocated to each batch based on the number of batches produced during the period. Therefore, the Company's costs to produce these materials are significantly impacted by the number of batches produced during the period. The volume of preclinical and clinical materials the Company produces is directly related to the number of clinical trials the Company and its collaborators are preparing for or currently have underway, the speed of enrollment in those trials, the dosage schedule of each clinical trial and the time period such trials last. Accordingly, the volume of preclinical and clinical materials produced, and therefore the Company's per batch costs to manufacture these preclinical and clinical materials, may vary significantly from period to period.

The Company may also produce research material for potential collaborators under material transfer agreements. Additionally, the Company performs research activities, including developing antibody specific conjugation processes, on behalf of its collaborators and potential collaborators during the early evaluation and preclinical testing stages of drug development. The Company records amounts received for research materials produced or services performed as a component of research and development support revenue. The Company also develops conjugation processes for materials for later stage testing and commercialization for certain collaborators. The Company is compensated at negotiated rates and may receive milestone payments for developing these processes which are recorded as a component of research and development support revenue.

The Company's development and commercialization license agreements have milestone payments which for reporting purposes are aggregated into three categories: (i) development milestones, (ii) regulatory milestones, and (iii) sales milestones. Development milestones are typically payable when a product candidate initiates or advances into different clinical trial phases. Regulatory milestones are typically payable upon submission for marketing approval with the U.S. Food and Drug Administration, or FDA, or other countries' regulatory authorities or on receipt of actual marketing approvals for the compound or for additional indications. Sales milestones are typically payable when annual sales reach certain levels.

At the inception of each agreement that includes milestone payments, the Company evaluates whether each milestone is substantive and at risk to both parties on the basis of the contingent nature of the milestone. This evaluation includes an assessment of whether (a) the consideration is commensurate with either (1) the entity's performance to achieve the milestone, or (2) the enhancement of the value of the delivered item(s) as a result of a specific outcome resulting from the entity's performance to achieve the milestone, (b) the consideration relates solely to past performance and (c) the consideration is reasonable relative to all of the deliverables and payment terms within the arrangement. The Company evaluates factors such as the scientific, regulatory, commercial and other risks that must be overcome to achieve the respective milestone, the level of effort and investment required to achieve the respective milestone and whether the milestone consideration is reasonable relative to all deliverables and payment terms in the arrangement in making this assessment.

Non-refundable development and regulatory milestones that are expected to be achieved as a result of the Company's efforts during the period of substantial involvement are considered substantive and are recognized as revenue upon the achievement of the milestone, assuming all other revenue recognition criteria are met. Milestones that are not considered substantive because we do not contribute effort to the achievement of such milestones are generally achieved after the period of substantial involvement and are recognized as revenue upon achievement of the milestone, as there are no undelivered elements remaining and no continuing performance obligations, assuming all other revenue recognition criteria are met.

Under the Company's development and commercialization license agreements, the Company receives royalty payments based upon its licensees' net sales of covered products. Generally, under these agreements the Company is to receive royalty reports and payments from its licensees approximately one quarter in arrears, that is, generally in the second month of the quarter after the licensee has sold the royalty bearing product or products. The Company recognizes royalty revenues when it can reliably estimate such amounts and collectability is reasonably assured. As such, the Company generally recognizes royalty revenues in the quarter reported to the Company by its licensees, or one quarter following the quarter in which sales by the Company's licensees occurred.

Right-to-Test Agreements

The Company's right-to-test agreements provide collaborators the right to (a) test the Company's TAP technology for a defined period of time through a research, or right-to-test, license, (b) take options, for a defined period of time, to specified targets and (c) upon exercise of those options, secure or "take" licenses to develop and commercialize products for the specified targets on established terms. Under these agreements, fees may be due to the Company (i) at the inception of the arrangement (referred to as "upfront" fees or payments), (ii) upon taking an option with respect to a specific target (referred to as option fees or payments earned, if any, when the option is "taken"), (iii) upon the exercise of a previously taken option to acquire a development and commercialization license(s) (referred to as exercise fees or payments earned, if any, when the development and commercialization license is "taken"), or (iv) some combination of all of these fees.

The accounting for right-to-test agreements is dependent on the nature of the options granted to the collaborative partner. Options are considered substantive if, at the inception of a right-to-test agreement, the Company is at risk as to whether the collaborative partner will choose to exercise the options to secure development and commercialization licenses. Factors that are considered in evaluating whether options are substantive include the overall objective of the arrangement, the benefit the collaborator might obtain from the agreement without exercising the options, the cost to exercise the options relative to the total upfront consideration, and the additional financial commitments or economic penalties imposed on the collaborator as a result of exercising the options.

For right-to-test agreements where the options to secure development and commercialization licenses to the Company's TAP technology are considered substantive, the Company does not consider the development and commercialization licenses to be a deliverable at the inception of the agreement. For those right-to-test agreements entered into prior to the adoption of ASU No. 2009-13 where the options to secure development and commercialization licenses are considered substantive, the Company has deferred the upfront payments received and recognizes this revenue over the period during which the collaborator could elect to take options for development and commercialization licenses. These periods are specific to each collaboration agreement. If a collaborator takes an option to acquire a development and commercialization license under these agreements, any substantive option fee is deferred and recognized over the life of the option, generally 12 to 18 months. If a collaborator exercises an option and takes a development and commercialization license to a specific target, the Company attributes the exercise fee to the development and commercialization license. Upon exercise of an option to acquire a development and commercialization license, the Company would also attribute any remaining deferred option fee to the development and commercialization license and apply the multiple-element revenue recognition criteria to the development and commercialization license and any other deliverables to determine the appropriate revenue recognition, which will be consistent with the Company's accounting policy for upfront payments on single-target licenses. In the event a right-to-test agreement were to be terminated, the Company would recognize as revenue any portion of the upfront fee that had not previously been recorded as revenue, but was classified as deferred revenue, at the date of such termination. None of the Company's right-to-test agreements entered into subsequent to the adoption of ASU No. 2009-13 has been determined to contain substantive options.

For right-to-test agreements where the options to secure development and commercialization licenses to the Company's TAP technology are not considered substantive, the Company considers the development and commercialization licenses to be a deliverable at the inception of the agreement and applies the multiple-element revenue recognition criteria to determine the appropriate revenue recognition. None of the Company's right-to-test agreements entered into prior to the adoption of ASU No. 2009-13 has been determined to contain non-substantive options.

The Company does not directly control when or if any collaborator will exercise its options for development and commercialization licenses. As a result, the Company cannot predict when or if it will recognize revenues in connection with any of the foregoing.

Inventory

Inventory costs relate to clinical trial materials being manufactured for sale to the Company's collaborators. Inventory is stated at the lower of cost or market as determined on a first-in, first-out (FIFO) basis.

Inventory at June 30, 2013 and 2012 is summarized below (in thousands):

	June 30,

	2013		2012
Raw materials	$	75	$	129
Work in process		628		1,159

Total	$	703	$	1,288

Raw materials inventory consists entirely of DM1 and DM4, proprietary cell-killing agents the Company developed as part of its TAP technology. All raw materials inventory is currently procured from a single supplier.

Work in process inventory consists of conjugate manufactured for sale to the Company's collaborators to be used in preclinical and clinical studies. All conjugate is made to order at the request of the collaborators and subject to the terms and conditions of respective supply agreements. As such, no reserve for work in process inventory is required.

Raw materials inventory cost is stated net of write-downs of $810,000 and $1.3 million as of June 30, 2013 and June 30, 2012, respectively. The write-downs represent the cost of raw materials that the Company considers to be in excess of a twelve-month supply based on firm, fixed orders and projections from its collaborators as of the respective balance sheet date.

Due to yield fluctuations, the actual amount of raw materials that will be produced in future periods under third-party supply agreements is highly uncertain. As such, the amount of raw materials produced could be more than is required to support the development of the Company's collaborators' product candidates. Such excess supply, as determined under the Company's inventory reserve policy, is charged to research and development expense.

The Company produces preclinical and clinical materials for its collaborators either in anticipation of or in support of preclinical studies and clinical trials, or for process development and analytical purposes. Under the terms of supply agreements with its collaborators, the Company generally receives rolling six-month firm, fixed orders for conjugate that the Company is required to manufacture, and rolling twelve-month manufacturing projections for the quantity of conjugate the collaborator expects to need in any given twelve-month period. The amount of clinical material produced is directly related to the number of collaborator anticipated or on-going clinical trials for which the Company is producing clinical material, the speed of enrollment in those trials, the dosage schedule of each clinical trial and the time period, if any, during which patients in the trial receive clinical benefit from the clinical materials. Because these elements are difficult to estimate over the course of a trial, substantial differences between collaborators' actual manufacturing orders and their projections could result in the Company's usage of raw materials varying significantly from estimated usage at an earlier reporting period. To the extent that a collaborator has provided the Company with a firm, fixed order, the collaborator is required by contract to reimburse the Company the full negotiated price of the conjugate, even if the collaborator subsequently cancels the manufacturing run.

The Company capitalizes raw material as inventory upon receipt and accounts for the raw material inventory as follows:

a)

to the extent that the Company has up to twelve months of firm, fixed orders and/or projections from its collaborators, the Company capitalizes the value of raw materials that will be used in the production of conjugate subject to these firm, fixed orders and/or projections;

b)

the Company considers more than a twelve month supply of raw materials that is not supported by firm, fixed orders and/or projections from its collaborators to be excess and establishes a reserve to reduce to zero the value of any such excess raw material inventory with a corresponding charge to research and development expense; and

c)

the Company also considers any other external factors and information of which it becomes aware and assesses the impact of such factors or information on the net realizable value of the raw material inventory at each reporting period.

During fiscal years 2013, 2012 and 2011, the Company obtained additional amounts of DMx from its supplier which yielded more material than would be required by the Company's collaborators over the next twelve months and as a result, the Company recorded $798,000, $748,000 and $1.7 million respectively, of charges to research and development expense related to raw material inventory identified as excess. The Company also recorded $38,000 as research and development expense to write down certain raw material inventory to its net realizable value in fiscal year 2012. No similar charges were recorded during fiscal years 2013 and 2011. Increases in the Company's on-hand supply of raw materials, or a reduction to the Company's collaborators' projections, could result in significant changes in the Company's estimate of the net realizable value of such raw material inventory. Reductions in collaborators' projections could indicate that the Company has excess raw material inventory and the Company would then evaluate the need to record write-downs as charges to research and development expense.

Unbilled Revenue

The majority of the Company's unbilled revenue at June 30, 2013 and 2012 represents research funding earned based on actual resources utilized under the Company's various collaborator agreements.

Restricted Cash

Restricted cash at June 30, 2013 and 2012 are cash balances securing irrevocable letters of credit required for security deposits for the Company's leased facilities.

Other Accrued Liabilities

Other accrued liabilities consisted of the following at June 30, 2013 and 2012 (in thousands):

	June 30,

	2013		2012
Accrued contract payments	$	2,406	$	1,773
Accrued clinical trial costs		1,849		865
Accrued professional services		678		677
Accrued employee benefits		411		351
Accrued public reporting charges		179		208
Other current accrued liabilities		526		715

Total	$	6,049	$	4,589

Research and Development Expenses

The Company's research and development expenses are charged to expense as incurred and relate to (i) research to evaluate new targets and to develop and evaluate new antibodies, linkers and cytotoxic agents, (ii) preclinical testing of its own and, in certain instances, its collaborators' product candidates, and the cost of its own clinical trials, (iii) development related to clinical and commercial manufacturing processes and (iv) manufacturing operations which also include raw materials. Payments made by the Company in advance for research and development services not yet provided and/or materials not yet delivered and accepted are recorded as prepaid expenses and are included in the accompanying Consolidated Balance Sheets as prepaid and other current assets.

Income Taxes

The Company uses the liability method to account for income taxes. Deferred tax assets and liabilities are determined based on differences between the financial reporting and income tax basis of assets and liabilities, as well as net operating loss carry forwards and tax credits and are measured using the enacted tax rates and laws that will be in effect when the differences reverse. A valuation allowance against net deferred tax assets is recorded if, based on the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized.

Financial Instruments and Concentration of Credit Risk

Cash and cash equivalents are primarily maintained with three financial institutions in the U.S. Deposits with banks may exceed the amount of insurance provided on such deposits. Generally, these deposits may be redeemed upon demand and, therefore, bear minimal risk. The Company's cash equivalents consist of money market funds with underlying investments primarily being U.S. Government- issued securities and high quality, short-term commercial paper. Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash, cash equivalents and marketable securities. The Company held no marketable securities as of June 30, 2013. The Company's investment policy, approved by the Board of Directors, limits the amount it may invest in any one type of investment, thereby reducing credit risk concentrations.

Derivative instruments include a portfolio of short duration foreign currency forward contracts intended to mitigate the risk of exchange fluctuations for existing or anticipated receivable and payable balances denominated in foreign currency. Derivatives are recorded at fair value and classified as other current assets or liabilities. The fair value of these instruments represents the present value of estimated future cash flows under the contracts, which are a function of underlying interest rates, currency rates, related volatility, counterparty creditworthiness and duration of the contracts. Changes in these factors or a combination thereof may affect the fair value of these instruments.

The Company does not designate foreign currency forward contracts as hedges for accounting purposes, and changes in the fair value of these instruments are recognized in earnings during the period of change. Because the Company enters into forward contracts only as an economic hedge, any gain or loss on the underlying foreign-denominated existing or anticipated receivable or payable balance would be offset by the loss or gain on the forward contract. Net gains (losses) on forward contracts for the years ended June 30, 2013, 2012 and 2011 were $197,000, $(173,000) and $189,000, respectively, and are included in the accompanying Consolidated Statement of Operations as other income (expense), net. As of June 30, 2013, the Company had an outstanding forward contract with a notional amount equivalent to approximately $57,000 (€41,000), maturing on October 7, 2013. As of June 30, 2012, the Company had outstanding forward contracts with notional amounts equivalent to approximately $3.3 million (€2.5 million). The Company does not anticipate using derivative instruments for any purpose other than hedging exchange rate exposure.

Cash Equivalents

All highly liquid financial instruments with maturities of three months or less when purchased are considered cash equivalents. As of June 30, 2013 and 2012, cash equivalents consisted of money market funds with underlying investments primarily being U.S. Government-issued securities and high quality, short-term commercial paper.

Fair Value of Financial Instruments

ASC Topic 820 defines fair value, establishes a framework for measuring fair value in accordance with accounting principles generally accepted in the U.S., and expands disclosures about fair value measurements. Certain provisions of ASC Topic 820 related to other non-financial assets and liabilities were adopted by the Company on July 1, 2009 and did not have a material impact on its financial position or results of operations upon adoption; however, this standard may impact the Company in subsequent periods and require additional disclosures.

Fair value is defined under ASC Topic 820 as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The standard describes a fair value hierarchy to measure fair value which is based on three levels of inputs, of which the first two are considered observable and the last unobservable, as follows:

•

Level 1—Quoted prices in active markets for identical assets or liabilities.

•

Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

•

Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

As of June 30, 2013, the Company held certain assets that are required to be measured at fair value on a recurring basis. The following table represents the fair value hierarchy for the Company's financial assets measured at fair value on a recurring basis as of June 30, 2013 (in thousands):

	Fair Value Measurements at June 30, 2013 Using

			Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	Total		(Level 1)		(Level 2)		(Level 3)
Cash, cash equivalents and restricted cash	$	197,191	$	197,191	$	—	$	—

	$	197,191	$	197,191	$	—	$	—

As of June 30, 2012, the Company held certain assets that are required to be measured at fair value on a recurring basis. The following table represents the fair value hierarchy for the Company's financial assets measured at fair value on a recurring basis as of June 30, 2012 (in thousands):

	Fair Value Measurements at June 30, 2012 Using

			Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	Total		(Level 1)		(Level 2)		(Level 3)
Cash, cash equivalents and restricted cash	$	163,488	$	163,488	$	—	$	—

	$	163,488	$	163,488	$	—	$	—

The fair value of the Company's cash equivalents is based primarily on quoted prices from active markets.

The carrying amounts reflected in the consolidated balance sheets for accounts receivable, unbilled revenue, prepaid and other current assets, accounts payable, accrued compensation, and other accrued liabilities approximate fair value due to their short-term nature.

Property and Equipment

Property and equipment are stated at cost. The Company provides for depreciation based upon expected useful lives using the straight-line method over the following estimated useful lives:


Machinery and equipment		5 years
Computer hardware and software		3 years
Furniture and fixtures		5 years
Leasehold improvements		Shorter of remaining lease term or 7 years

Maintenance and repairs are charged to expense as incurred. Upon retirement or sale, the cost of disposed assets and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is included in the statement of operations. The Company recorded $21,000, $(51,000) and $(9,000) of gains (losses) on the sale/disposal of certain furniture and equipment during the years ended June 30, 2013, 2012, and 2011, respectively.

Impairment of Long-Lived Assets

In accordance with ASC Topic 360, "Property, Plant, and Equipment," the Company continually evaluates whether events or circumstances have occurred that indicate that the estimated remaining useful life of its long-lived assets may warrant revision or that the carrying value of these assets may be impaired. The Company evaluates the realizability of its long-lived assets based on cash flow expectations for the related asset. Any write-downs are treated as permanent reductions in the carrying amount of the assets. Based on this evaluation, the Company believes that, as of each of the balance sheet dates presented, none of the Company's long-lived assets were impaired.

Computation of Net Loss Per Common Share

Basic and diluted net loss per common share is calculated based upon the weighted average number of common shares outstanding during the period. The Company's common stock equivalents, as calculated in accordance with the treasury-stock method, are shown in the following table (in thousands):

	June 30,

	2013		2012		2011
Options outstanding to purchase common stock and unvested restricted stock		7,703		6,442		6,491
Common stock equivalents under treasury stock method		2,149		2,194		1,901

The Company's common stock equivalents have not been included in the net loss per share calculation because their effect is anti-dilutive due to the Company's net loss position.

Stock-based Compensation

As of June 30, 2013, the Company is authorized to grant future awards under one employee share-based compensation plan, which is the ImmunoGen, Inc. 2006 Employee, Director and Consultant Equity Incentive Plan, or the 2006 Plan. At the annual meeting of shareholders on November 13, 2012, an amendment to the 2006 Plan was approved and an additional 3,500,000 shares were authorized for issuance under this plan. As amended, the 2006 Plan provides for the issuance of Stock Grants, the grant of Options and the grant of Stock-Based Awards for up to 12,000,000 shares of the Company's common stock, as well as any shares of common stock that are represented by awards granted under the previous stock option plan, the ImmunoGen, Inc. Restated Stock Option Plan, or the Former Plan, that are forfeited, expire or are cancelled without delivery of shares of common stock; provided, however, that no more than 5,900,000 shares shall be added to the 2006 Plan from the Former Plan, pursuant to this provision. Option awards are granted with an exercise price equal to the market price of the Company's stock at the date of grant. Options vest at various periods of up to four years and may be exercised within ten years of the date of grant.

The stock-based awards are accounted for under ASC Topic 718, "Compensation—Stock Compensation." Pursuant to Topic 718, the estimated grant date fair value of awards is charged to the statement of operations over the requisite service period, which is the vesting period. Such amounts have been reduced by an estimate of forfeitures of all unvested awards. The fair value of each stock option is estimated on the date of grant using the Black-Scholes option-pricing model with the weighted average assumptions noted in the following table. As the Company has not paid dividends since inception, nor does it expect to pay any dividends for the foreseeable future, the expected dividend yield assumption is zero. Expected volatility is based exclusively on historical volatility data of the Company's stock. The expected term of stock options granted is based exclusively on historical data and represents the period of time that stock options granted are expected to be outstanding. The expected term is calculated for and applied to one group of stock options as the Company does not expect substantially different exercise or post-vesting termination behavior amongst its employee population. The risk-free rate of the stock options is based on the U.S. Treasury rate in effect at the time of grant for the expected term of the stock options.

	Year Ended June 30,

	2013	2012	2011
Dividend	None	None	None
Volatility	60.44%	59.70%	58.81%
Risk-free interest rate	0.87%	2.16%	2.43%
Expected life (years)	6.3	7.1	7.2

Using the Black-Scholes option-pricing model, the weighted average grant date fair values of options granted during fiscal 2013, 2012 and 2011 were $8.60, $9.00, and $5.51 per share, respectively.

A summary of option activity under the 2006 Plan as of June 30, 2013, and changes during the twelve month period then ended is presented below (in thousands, except weighted-average data):

			Weighted- Average Exercise Price			Aggregate Intrinsic Value

Outstanding at June 30, 2012	6,442		$	8.98
Granted	2,047		$	15.22
Exercised	(666	)	$	6.05
Forfeited/Canceled	(170	)	$	13.87

Outstanding at June 30, 2013	7,653		$	10.79	6.89	$	44,351

Outstanding at June 30, 2013—vested or unvested and expected to vest	7,466		$	10.70	6.84	$	43,991

Exercisable at June 30, 2013	4,202		$	7.97	5.53	$	36,220

In November 2012, the Company granted an officer of the Company 50,000 shares of restricted stock upon hire. Pursuant to the agreement, the shares vest ratably in quarterly installments over the subsequent four years. The fair value of the restricted stock was determined by the closing price on the date of grant. A summary of restricted stock activity under the 2006 Plan as of June 30, 2013, and changes during the twelve month period then ended is presented below (in thousands, except weighted-average data):

		Weighted- Average Exercise Price

Unvested at June 30, 2012	—	$	—
Granted	50,000		11.93

Unvested at June 30, 2013	50,000	$	11.93

Stock compensation expense related to stock options and restricted stock awards granted under the 2006 Plan was $12.4 million, $9.9 million and $5.5 million during the fiscal years ended June 30, 2013, 2012, and 2011, respectively. As of June 30, 2013, the estimated fair value of unvested employee awards was approximately $17.4 million, net of estimated forfeitures. The weighted-average remaining vesting period for these awards is approximately two years.

A summary of option activity for options vested during the fiscal years ended June 30, 2013, 2012 and 2011 is presented below (in thousands):

	Year Ended June 30,

	2013		2012		2011
Total fair value of options vested	$	9,670	$	5,647	$	3,427
Total intrinsic value of options exercised		6,737		12,476		3,467
Cash received for exercise of stock options		4,026		6,988		2,719

Comprehensive Loss

The Company presents comprehensive loss in accordance with ASC Topic 220, Comprehensive Income. Comprehensive loss is comprised of the Company's net loss for the years ended June 30, 2013 and 2012 and the Company's net loss and unrealized gains on available-for-sale marketable securities for the year ended June 30, 2011.

Segment Information

During the three fiscal years ended June 30, 2013, the Company continued to operate in one reportable business segment under the management approach of ASC Topic 280, Segment Reporting, which is the business of discovery of monoclonal antibody-based anticancer therapeutics.

The percentages of revenues recognized from significant customers of the Company in the years ended June 30, 2013, 2012 and 2011 are included in the following table:

	Year Ended June 30,

Collaborative Partner:	2013	2012	2011
Amgen	6%	30%	41%
Bayer HealthCare	4%	15%	17%
Biotest	5%	14%	9%
Novartis	49%	16%	7%
Roche	30%	0%	0%
Sanofi	3%	23%	23%

There were no other customers of the Company with significant revenues in the years ended June 30, 2013, 2012 and 2011.

Recent Accounting Pronouncements

In July 2013, the FASB issued guidance to address the diversity in practice related to the financial statement presentation of unrecognized tax benefits as either a reduction of a deferred tax asset or a liability when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. This guidance is effective prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2013. The adoption of this guidance is not expected to have a material impact on the Company's consolidated financial statements.

- Definition

The entire disclosure for the organization, consolidation and basis of presentation of financial statements disclosure, and significant accounting policies of the reporting entity. May be provided in more than one note to the financial statements, as long as users are provided with an understanding of (1) the significant judgments and assumptions made by an enterprise in determining whether it must consolidate a VIE and/or disclose information about its involvement with a VIE, (2) the nature of restrictions on a consolidated VIE's assets reported by an enterprise in its statement of financial position, including the carrying amounts of such assets, (3) the nature of, and changes in, the risks associated with an enterprise's involvement with the VIE, and (4) how an enterprise's involvement with the VIE affects the enterprise's financial position, financial performance, and cash flows. Describes procedure if disclosures are provided in more than one note to the financial statements.

+ References+ Details

Agreements	12 Months Ended
Agreements	Jun. 30, 2013
Agreements
Agreements	C. Agreements Significant Collaborative Agreements Roche In May 2000, the Company granted Roche, through its Genentech unit, an exclusive license to the Company's maytansinoid TAP technology for use with antibodies or other proteins that target HER2, such as trastuzumab. Under the terms of this agreement, Roche has exclusive worldwide rights to develop and commercialize maytansinoid TAP compounds targeting HER2. In February 2013, the US FDA granted marketing approval to the anti-HER2 TAP compound Kadcyla. Roche is responsible for the manufacturing, product development and marketing of any products resulting from the agreement. The Company is compensated for any preclinical and clinical materials that the Company manufactures under the agreement. The Company received a $2 million non-refundable upfront payment from Roche upon execution of the agreement. The Company is also entitled to receive up to a total of $44 million in milestone payments, plus royalties on the commercial sales of Kadcyla or any other resulting products. Total milestones are categorized as follows: development milestones—$13.5 million; and regulatory milestones—$30.5 million. Through June 30, 2013, the Company has received and recognized $13.5 million and $10.5 million in development and regulatory milestone payments, respectively, related to Kadcyla. The US marketing approval of Kadcyla in February 2013 triggered a $10.5 million regulatory milestone payment to the Company. Based on an evaluation of the effort contributed to the achievement of this milestone, the Company determined this milestone was not substantive. In consideration that there were no undelivered elements remaining, no continuing performance obligations and all other revenue recognition criteria had been met, the Company recognized the $10.5 million non-refundable payment as revenue upon achievement of the milestone, which is included in license and milestone fees for the fiscal year ended June 30, 2013. The next potential milestone the Company will be entitled to receive will be either a $5 million regulatory milestone for marketing approval of Kadcyla in Europe or a $5 million regulatory milestone for marketing approval of Kadcyla in Japan depending on which occurs first. Based on an evaluation of the effort contributed to the achievement of these milestones, the Company has determined these milestones are not substantive. The Company receives royalty reports and payments related to sales of Kadcyla from Roche one quarter in arrears. In accordance with the Company's revenue recognition policy, $592,000 of royalties on net sales of Kadcyla for the period ended March 31, 2013 were recorded in the Company's fourth quarter of fiscal 2013 and are included in royalty revenues for the fiscal year ended June 30, 2013. Roche, through its Genentech unit, also has licenses for the exclusive right to use the Company's maytansinoid TAP technology with antibodies to four undisclosed targets, which were granted under the terms of a separate May 2000 right-to-test agreement with Genentech. For each of these licenses the Company received a $1 million license fee and is entitled to receive up to a total of $38 million in milestone payments and also royalties on the sales of any resulting products. The total milestones are categorized as follows: development milestones—$8 million; regulatory milestones—$20 million; and sales milestones—$10 million. The Company has not received any milestone payments from these agreements through June 30, 2013. Roche is responsible for the development, manufacturing, and marketing of any products resulting from these licenses. The next potential milestone the Company will be entitled to receive under any of these agreements will be a development milestone for filing of an IND application which will result in a $1 million payment being due. At the time of execution of each of these development and commercialization licenses, there was significant uncertainty as to whether this milestone would be achieved. In consideration of this, as well as the Company's past involvement in the research and manufacturing these products, this milestone was deemed substantive. Roche no longer has the right to take additional licenses under the right-to-test agreement. The Company received non-refundable technology access fees totaling $5 million for the eight-year term of the right-to-test agreement. The upfront fees were deferred and recognized ratably over the period during which Genentech could elect to obtain product licenses. Amgen In September 2000, the Company entered into a ten-year right-to-test agreement with Abgenix, Inc., which was later acquired by Amgen. The agreement provided Amgen with the right to (a) test the Company's maytansinoid TAP technology with Amgen's antibodies under a right-to-test, or research, license, (b) take options, with certain restrictions, to individual targets selected by Amgen on either an exclusive and non-exclusive basis for specified option periods and (c) upon exercise of those options, take exclusive or non-exclusive licenses to use the Company's maytansinoid TAP technology to develop and commercialize products for the specified targets on previously agreed-upon terms. The Company received a $5 million technology access fee in September 2000. For each exclusive development and commercialization license taken, the Company is entitled to receive an exercise fee of $1 million and up to a total of $34 million in milestone payments, plus royalties on the commercial sales of any resulting products. The total milestones per exclusive development and commercialization license are categorized as follows: development milestones—$9 million; regulatory milestones—$20 million; and sales milestones—$5 million. For each non-exclusive development and commercialization license taken, the Company is entitled to receive an exercise fee of $500,000 and up to a total of $17 million in milestone payments, plus royalties on the commercial sales of any resulting products. The total milestones per non-exclusive development and commercialization license are categorized as follows: development milestones—$4.5 million; regulatory milestones—$10 million; and sales milestones—$2.5 million. Amgen is responsible for the manufacturing, product development and marketing of any products resulting from the agreement. Amgen no longer has the right to take additional options under the agreement and there are no unexercised options outstanding. Under the right-to-test agreement, in September 2009, November 2009 and December 2012, Amgen took three exclusive development and commercialization licenses, for which the Company received an exercise fee of $1 million for each license taken. In May 2013, Amgen took one non-exclusive development and commercialization license, for which the Company received an exercise fee of $500,000. The Company has deferred each exercise fee and is recognizing these amounts as revenue ratably over the respective estimated periods of its substantial involvement. In November 2011, the IND applications to the FDA for two compounds developed under two of the exclusive development and commercialization licenses became effective, which triggered two $1 million milestone payments to the Company. These payments are included in license and milestone fees for the year ended June 30, 2012. At the time of execution of each of these exclusive development and commercialization licenses, there was significant uncertainty as to whether these received and recognized milestones would be achieved. In consideration of this, as well as the Company's past involvement in the research and manufacturing of these product candidates, these milestones were deemed substantive. The next potential milestone the Company will be entitled to receive under either of these development and commercialization licenses will be a development milestone for the first dosing of a patient in a Phase II clinical trial, which will result in a $3 million payment being due. The next potential milestones the Company will be entitled to receive under the December 2012 and May 2013 development and commercialization licenses will be a development milestone for IND approval which will result in a $1 million payment and a $500,000 milestone payment, respectively, being due to the Company. At the time of execution of each of these development and commercialization licenses, there was significant uncertainty as to whether these milestones would be achieved. In consideration of this, as well as the Company's past involvement in the research and manufacturing of these product candidates, these milestones were deemed substantive. Sanofi In July 2003, the Company entered into a broad collaboration agreement with Sanofi (formerly Aventis) to discover, develop and commercialize antibody-based products. The collaboration agreement provides Sanofi with worldwide development and commercialization rights to new antibody-based products directed to targets that are included in the collaboration, including the exclusive right to use the Company's maytansinoid TAP technology in the creation of products developed to these targets. The product candidates (targets) as of June 30, 2013 in the collaboration include SAR3419 (CD19), SAR650984 (CD38), SAR566658 (DS6, also known as CA6) and two earlier-stage compounds that have yet to be disclosed. For each of the targets included in the collaboration at this time, the Company is entitled to receive up to a total of $21.5 million in milestone payments, plus royalties on the commercial sales of any resulting products. The total milestones are categorized as follows: development milestones—$7.5 million; and regulatory milestones—$14 million. Through June 30, 2013, the Company has received and recognized an aggregate of $16.5 million in milestone payments for compounds covered under this agreement now or in the past, including a $500,000 development milestone related to an undisclosed target which is included in license and milestone fee revenue for the year ended June 30, 2013, a $3 million milestone payment related to the initiation of a Phase IIb clinical trial (as defined in the agreement) for SAR3419, which is included in license and milestone fee revenue for the year ended June 30, 2012, as well as a $1 million milestone payment earned in September 2010 related to the initiation of Phase I clinical testing of SAR566658 which is included in license and milestone fee revenue for the year ended June 30, 2011. At the time of execution of this agreement, there was significant uncertainty as to whether these received and recognized milestones would be achieved. In consideration of this, as well as the Company's past involvement in the research and manufacturing of these product candidates, these milestones were deemed substantive. The next potential milestone the Company will be entitled to receive with respect to both SAR566658 and SAR650984 will be a development milestone for initiation of a Phase IIb clinical trial (as defined in the agreement), which will result in each case in a $3 million payment being due. The next potential milestone the Company will be entitled to receive with respect to SAR3419 will be for initiation of a Phase III clinical trial, which will result in a $3 million payment being due. The next potential milestone the Company will be entitled to receive for each of the unidentified targets will be a development milestone for commencement of a Phase I clinical trial, which will result in a $1 million payment being due. At the time of execution of this agreement, there was significant uncertainty as to whether these milestones would be achieved. In consideration of this, as well as the Company's past involvement in the research and manufacturing of these product candidates, these milestones were deemed substantive. In December 2006, the Company entered into a separate right-to-test agreement with Sanofi. The agreement provides Sanofi with the right to (a) test the Company's maytansinoid TAP technology with Sanofi's antibodies to targets that were not included in the collaboration agreement described above under a right-to-test, or research, license, (b) take exclusive options, with certain restrictions, to specified targets for specified option periods and (c) upon exercise of those options, take exclusive licenses to use the Company's maytansinoid TAP technology to develop and commercialize products directed to the specified targets on terms agreed upon at the inception of the right-to-test agreement. For each development and commercialization license taken, the Company is entitled to receive an exercise fee of $2 million and up to a total of $30 million in milestone payments, plus royalties on the commercial sales of any resulting products. The total milestones are categorized as follows: development milestones—$10 million; and regulatory milestones—$20 million. No development and commercialization license has yet been taken under this agreement. Execution of the first license will entitle the Company to receive an exercise fee in the amount of $2 million. Sanofi is responsible for the manufacturing, product development and marketing of any products resulting from the agreement. The Company received an aggregate of $4 million under the right-to-test agreement, of which $500,000 was received in December 2006 upon execution of the agreement, and $3.5 million of which was received in August 2008 upon Sanofi's activation of its rights under the agreement. The right-to-test agreement had a three-year original term from the activation date and was renewed by Sanofi in August 2011for its final three-year term by payment of a $2 million fee. The Company has deferred the $2 million extension fee and is recognizing this amount as revenue over the period during which Sanofi can take an option for a development and commercialization license. Biotest In July 2006, the Company granted Biotest an exclusive development and commercialization license to our maytansinoid TAP technology for use with antibodies that target CD138. The product candidate BT-062 is in development under this agreement. Biotest is responsible for the manufacturing, product development and marketing of any products resulting from the agreement. The Company received a $1 million upfront payment upon execution of the agreement and could receive up to $35.5 million in milestone payments, as well as royalties on the commercial sales of any resulting products. The total milestones are categorized as follows: development milestones—$4.5 million; and regulatory milestones—$31 million. The Company receives payments for manufacturing any preclinical and clinical materials made at the request of Biotest. In September 2008, Biotest began Phase I evaluation of BT062 which triggered a $500,000 milestone payment to the Company. At the time of execution of this agreement, there was significant uncertainty as to whether this received and recognized milestone would be achieved. In consideration of this, as well as the Company's past involvement in the research and manufacturing of this product candidate, this milestone was deemed substantive. The next potential milestone the Company will be entitled to receive will be a development milestone for commencement of a Phase IIb clinical trial (as defined in the agreement) which will result in a $2 million payment being due. At the time of execution of this agreement, there was significant uncertainty as to whether this milestone would be achieved. In consideration of this, as well as the Company's past involvement in the research and manufacturing of this product, this milestone was deemed substantive. The agreement also provides the Company with the right to elect at specific stages during the clinical evaluation of any compound created under this agreement, to participate in the U.S. development and commercialization of that compound in lieu of receiving the milestone payments not yet earned and royalties on sales in the U.S. The Company can exercise this right during an exercise period specified in the agreement by notice and payment to Biotest of an agreed upon opt-in fee of $15 million. Upon exercise of this right, the Company would share equally with Biotest the associated costs of product development and commercialization in the U.S. along with the profit, if any, from product sales in the U.S. Bayer HealthCare In October 2008, the Company granted Bayer HealthCare an exclusive development and commercialization license to the Company's maytansinoid TAP technology for use with antibodies or other proteins that target mesothelin. Bayer HealthCare is responsible for the research, development, manufacturing and marketing of any products resulting from the license. The Company received a $4 million upfront payment upon execution of the agreement, and—for each compound developed and marketed by Bayer HealthCare under this collaboration—the Company is entitled to receive a total of $170.5 million in milestone payments, plus royalties on the commercial sales of any resulting products. The total milestones are categorized as follows: development milestones—$16 million; regulatory milestones—$44.5 million; and sales milestones—$110 million. Through June 30, 2013, the Company has received and recognized an aggregate of $3 million in milestone payments under this agreement. At the time of execution of this agreement, there was significant uncertainty as to whether these received and recognized milestones would be achieved. In consideration of this, as well as the Company's past involvement in the research and supply of cytotoxic agent for this product candidate, these milestones were deemed substantive. The next potential milestone the Company will be entitled to receive will be a development milestone for commencement of a non-pivotal Phase II clinical trial, which will result in a $4 million payment being due. At the time of execution of this agreement, there was significant uncertainty as to whether this milestone would be achieved. In consideration of this, as well as the Company's past involvement in the research and supply of cytotoxic agent for this product candidate, this milestone was deemed substantive. The Company had previously deferred the $4 million upfront payment received and was recognizing this amount as revenue ratably over the estimated period of substantial involvement. The Company had previously estimated this development period would conclude at the end of non-pivotal Phase II testing. During the first quarter of fiscal 2012, Bayer HealthCare initiated Phase I clinical testing of its product candidate. In reaching this stage of clinical testing, Bayer HealthCare developed its own processes for manufacturing required clinical material and produced clinical material in its own manufacturing facility. Considering that Bayer HealthCare was able to accomplish this without significant reliance on the Company, and considering that the Company's expected future involvement would be primarily supplying Bayer HealthCare with small quantities of cytotoxic agents for a limited period of time, the Company believed its period of substantial involvement would end prior to the completion of non-pivotal Phase II testing. As a result of this determination, beginning in September 2011, the Company recognized the balance of the upfront payment as revenue ratably through September 2012. This change in estimate resulted in an increase to license and milestone fees of approximately $1.2 million for the fiscal year ending June 30, 2012 compared to amounts that would have been recognized pursuant to the Company's previous estimate. Novartis In October 2010, the Company entered into a three-year right-to-test agreement with Novartis Institutes for BioMedical Research, Inc. (Novartis). The agreement provides Novartis with the right to (a) test the Company's TAP technology with individual antibodies selected by Novartis under a right-to-test, or research, license, (b) take exclusive options, with certain restrictions, to individual targets selected by Novartis for specified option periods and (c) upon exercise of those options, take exclusive licenses to use the Company's TAP technology to develop and commercialize products for a specified number of individual targets on terms agreed upon at the inception of the right-to-test agreement. The initial three-year term of the right-to-test agreement may be extended by Novartis for up to two additional one-year periods by payment of additional consideration. The terms of the right-to-test agreement require Novartis to exercise its options for the development and commercialization licenses by the end of the term of the research license. The Company received a $45 million upfront payment in connection with the execution of the right-to-test agreement, and for each development and commercialization license for a specific target, the Company is entitled to receive an exercise fee of $1 million and up to a total of $199.5 million in milestone payments, plus royalties on the commercial sales of any resulting products. The total milestones are categorized as follows: development milestones—$22.5 million; regulatory milestones—$77 million; and sales milestones—$100 million. The Company also is entitled to receive payments for research and development activities performed on behalf of Novartis. Novartis is responsible for the manufacturing, product development and marketing of any products resulting from this agreement. Effective March 29, 2013, the Company and Novartis amended the right-to-test agreement so that Novartis can take a license to develop and commercialize products directed at two pre-defined and related undisclosed targets, one target licensed on an exclusive basis and the other target initially licensed on a non-exclusive basis. The target licensed on a non-exclusive basis may be converted to an exclusive target by notice and payment to us of an agreed upon fee of at least $5 million, depending on specific circumstances. The Company was entitled to a $3.5 million fee in connection with the execution of the amendment to the agreement. The Company may be required to credit this fee against future milestone payments if Novartis discontinues the development of a specified product under certain circumstances. In connection with the amendment, on March 29, 2013, Novartis took the license referenced above under the right-to-test agreement, as amended, enabling it to develop and commercialize products directed at the two targets. The Company was entitled to a $1 million upfront fee with the execution of this license. Additionally, the execution of this license provides the Company the opportunity to receive milestone payments totaling $199.5 million (development milestones—$22.5 million; regulatory milestones—$77 million; and sales milestones—$100 million) or $238 million (development milestones—$22.5 million; regulatory milestones—$115.5 million; and sales milestones—$100 million), depending on the composition of any resulting products. The first potential milestone the Company will be entitled to receive will be a $5.0 million development milestone for commencement of a Phase I clinical trial. At the time of execution of this agreement, there was significant uncertainty as to whether this milestone would be achieved. In consideration of this, as well as the Company's past involvement in the research and manufacturing of this product candidate, this milestone was deemed substantive. Additionally, the Company is entitled to receive royalties on product sales, if any. Novartis also has the right to convert the noted non-exclusive license to an exclusive license, in which case the Company would be entitled to receive a conversion fee and, depending on the composition of resultant products, an upward adjustment on milestone payments. In accordance with ACS 605-25 (as amended by ASU No. 2009-13), the Company identified all of the deliverables at the inception of the right-to-test agreement and subsequently when amended. The significant deliverables were determined to be the right-to-test, or research, license, the development and commercialization licenses, rights to future technological improvements, and the research services. The options to obtain development and commercialization licenses in the right-to-test agreement were determined not to be substantive and, as a result, the exclusive development and commercialization licenses were considered deliverables at the inception of the right-to-test agreement. Factors that were considered in determining the options were not substantive included (i) the overall objective of the agreement was for Novartis to obtain development and commercialization licenses, (ii) the size of the exercise fee of $1 million for each development and commercialization license obtained is not significant relative to the $45 million upfront payment that was due at the inception of the right-to-test agreement, (iii) the limited economic benefit that Novartis could obtain from the right-to-test agreement unless it exercised its options to obtain development and commercialization licenses, and (iv) the lack of economic penalties as a result of exercising the options. The Company has determined that the research license together with the development and commercialization licenses represent one unit of accounting as the research license does not have stand-alone value from the development and commercialization licenses due to the lack of transferability of the research license and the limited economic benefit Novartis would derive if they did not obtain any development and commercialization licenses. The Company has also determined that this unit of accounting does have stand-alone value from the rights to future technological improvements and the research services. The rights to future technological improvements and the research services are considered separate units of accounting as each of these was determined to have stand-alone value. The rights to future technological improvements have stand-alone value as Novartis would be able to use those items for their intended purpose without the undelivered elements. The research services have stand-alone value as similar services are sold separately by other vendors. The estimated selling prices for the development and commercialization licenses are the Company's best estimate of selling price and were determined based on market conditions, similar arrangements entered into by third parties, including pricing terms offered by our competitors for single-target development and commercialization licenses that utilize antibody-drug conjugate technology, and entity-specific factors such as the pricing terms of the Company's previous single-target development and commercialization licenses, recent preclinical and clinical testing results of therapeutic products that use the Company's TAP technology, and the Company's pricing practices and pricing objectives. The estimated selling price of the right to technological improvements is the Company's best estimate of selling price and was determined by estimating the probability that technological improvements will be made and the probability that such technological improvements made will be used by Novartis. In estimating these probabilities, we considered factors such as the technology that is the subject of the development and commercialization licenses, our history of making technological improvements, and when such improvements, if any, were likely to occur relative to the stage of development of any product candidates pursuant to the development and commercialization licenses. The Company's estimate of probability considered the likely period of time that any improvements would be utilized, which was estimated to be ten years following delivery of a commercialization and development license. The value of any technological improvements made available after this ten year period was considered to be de minimis due to the significant additional costs that would be incurred to incorporate such technology into any existing product candidates. The estimate of probability was multiplied by the estimated selling price of the development and commercialization licenses and the resulting cash flow was discounted at a rate of 16%, representing the Company's estimate of its cost of capital. The estimated selling price of the research services was based on third-party evidence given the nature of the research services to be performed for Novartis and market rates for similar services. The total arrangement consideration of $55.2 million (which comprises the $45 million upfront payment, the amendment fee of $3.5 million, the exercise fee for each license, and the expected fees for the research services to be provided under the remainder of the arrangement) was allocated to the deliverables based on the relative selling price method as follows: $50.4 million to the development and commercialization licenses; $4.1 million to the rights to future technological improvements; and $710,000 to the research services. Upon execution of the development and commercialization license taken by Novartis in March 2013, the Company recorded $11.1 million of the $50.4 million of the arrangement consideration outlined above, which is included in license and milestone fee revenue for the fiscal year ended June 30, 2013. With this first development and commercialization license taken, the amount of the total arrangement consideration allocated to future technological improvements will commence to be recognized as revenue ratably over the period the Company is obligated to make available any technological improvements, which is equivalent to the estimated term of the agreement. The Company estimates the term of a development and commercialization license to be approximately 25 years, which reflects management's estimate of the time necessary to develop and commercialize products pursuant to the license plus the estimated royalty term. The Company reassesses the estimated term at the end of each reporting period. The Company will recognize as license revenue an equal amount of the total remaining $39.3 million of arrangement consideration allocated to the development and commercialization licenses as each individual license is delivered to Novartis upon Novartis' exercise of its remaining options to such licenses. The Company does not control when Novartis will exercise its options for development and commercialization licenses. As a result, the Company cannot predict when it will recognize the related license revenue except that it will be within the term of the research license. The Company will recognize research services revenue as the related services are delivered. Lilly In December 2011, the Company entered into a three-year right-to-test agreement with Eli Lilly and Company (Lilly). The agreement provides Lilly with the right to (a) take exclusive options, with certain restrictions, to individual targets selected by Lilly for specified option periods, (b) test the Company's maytansinoid TAP technology with Lilly's antibodies directed to the optioned targets under a right-to-test, or research, license, and (c) upon exercise of those options, take exclusive licenses to use the Company's maytansinoid TAP technology to develop and commercialize products for a specified number of individual targets on terms agreed upon at the inception of the right-to-test agreement. The terms of the right-to-test agreement require Lilly to exercise its options for the development and commercialization licenses by the end of the term of the research license. In August 2013, Lilly took its first exclusive license to a single target. The Company received a $20 million upfront payment in connection with the execution of the right-to-test agreement, and for the first development and commercialization license taken, which occurred in August 2013, the Company is entitled to receive up to a total of $200.5 million in milestone payments, plus royalties on the commercial sales of any resulting products. For each subsequent development and commercialization license taken, the Company is entitled to receive an exercise fee in the amount of $2 million and up to a total of $199 million in milestone payments, plus royalties on the commercial sales of any resulting products. The total milestones are categorized as follows: development milestones—$30.5 million for the first development and commercialization license and $29 million for each subsequent license; regulatory milestones—$70 million; and sales milestones—$100 million. The next payment the Company could receive would either be a $5 million development milestone payment with the initiation of a Phase I clinical trial under the first development and commercialization license taken, or a $2 million exercise fee for the execution of a second license. At the time of execution of this agreement, there was significant uncertainty as to whether the milestone related to initiation of a Phase I clinical trial under the first development and commercialization license would be achieved. In consideration of this, as well as the Company's expected involvement in the research and manufacturing of these product candidates, this milestone was deemed substantive. The Company also is entitled to receive payments for delivery of cytotoxic agents to Lilly and research and development activities performed on behalf of Lilly. Lilly is responsible for the manufacturing, product development and marketing of any products resulting from this collaboration. In accordance with ASC 605-25 (as amended by ASU No. 2009-13), the Company identified all of the deliverables at the inception of the right-to-test agreement. The significant deliverables were determined to be the right-to-test, or research, license, the exclusive development and commercialization licenses, rights to future technological improvements, delivery of cytotoxic agents and the research services. The options to obtain development and commercialization licenses in the right-to-test agreement were determined not to be substantive and, as a result, the exclusive development and commercialization licenses were considered deliverables at the inception of the right-to-test agreement. Factors that were considered in determining the options were not substantive included (i) the overall objective of the agreement was for Lilly to obtain development and commercialization licenses, (ii) the size of the exercise fees of $2 million for each development and commercialization license taken beyond the first license is not significant relative to the $20 million upfront payment that was due at the inception of the right-to-test agreement, (iii) the limited economic benefit that Lilly could obtain from the right-to-test agreement unless it exercised its options to obtain development and commercialization licenses, and (iv) the lack of economic penalties as a result of exercising the options. The Company has determined that the research license together with the development and commercialization licenses represent one unit of accounting as the research license does not have stand-alone value from the development and commercialization licenses due to the lack of transferability of the research license and the limited economic benefit Lilly would derive if they did not obtain any development and commercialization licenses. The Company has also determined that this unit of accounting has stand-alone value from the rights to future technological improvements, the delivery of cytotoxic agents and the research services. The rights to future technological improvements, delivery of cytotoxic agents and the research services are considered separate units of accounting as each of these was determined to have stand-alone value. The rights to future technological improvements have stand-alone value as Lilly would be able to use those items for their intended purpose without the undelivered elements. The research services and cytotoxic agents have stand-alone value as similar services and products are sold separately by other vendors. The estimated selling prices for the development and commercialization licenses are the Company's best estimate of selling price and were determined based on market conditions, similar arrangements entered into by third parties, including pricing terms offered by our competitors for single-target development and commercialization licenses that utilize antibody-drug conjugate technology, and entity-specific factors such as the pricing terms of the Company's previous single-target development and commercialization licenses, recent preclinical and clinical testing results of therapeutic products that use the Company's TAP technology, and the Company's pricing practices and pricing objectives. The estimated selling price of the rights to technological improvements is the Company's best estimate of selling price and was determined by estimating the probability that technological improvements will be made, and the probability that technological improvements made will be used by Lilly. In estimating these probabilities, we considered factors such as the technology that is the subject of the development and commercialization licenses, our history of making technological improvements, and when such improvements, if any, were likely to occur relative to the stage of development of any product candidates pursuant to the development and commercialization licenses. over the company's estimate of probability considered the likely period of time that any improvements would be utilized, which was estimated to be ten years following delivery of a commercialization and development license. The value of any technological improvements made available after this ten year period was considered to be de minimis due to the significant additional costs that would be incurred to incorporate such technology into any existing product candidates. The estimate of probability was multiplied by the estimated selling price of the development and commercialization licenses and the resulting cash flow was discounted at a rate of 16%, representing the Company's estimate of its cost of capital. The estimated selling price of the cytotoxic agent was based on third-party evidence given market rates for the manufacture of such cytotoxic agents. The estimated selling price of the research services was based on third-party evidence given,the nature of the research services to be performed for Lilly and market rates for similar services. The total arrangement consideration of $28.2 million (which comprises the $20 million upfront payment, the exercise fee, if any, for each license, the expected fees for the research services to be provided and the cytotoxic agent to be delivered under the arrangement) was allocated to the deliverables based on the relative selling price method as follows: $23.5 million to the development and commercialization licenses; $0.6 million to the rights to future technological improvements, $0.8 million to the sale of cytotoxic agent; and $3.3 million to the research services. The Company will recognize as license revenue an equal amount of the total arrangement consideration allocated to the development and commercialization licenses as each individual license is delivered to Lilly upon Lilly's exercise of its options to such licenses. At the time the first license is taken, the amount of the total arrangement consideration allocated to future technological improvements will commence to be recognized as revenue ratably over the period the Company is obligated to make available any technological improvements, which is the equivalent to the estimated term of the license. The Company estimates the term of a development and commercialization license to be approximately 25 years, which reflects management's estimate of the time necessary to develop and commercialize therapeutic products pursuant to the license plus the estimated royalty term. The Company will be required to reassess the estimated term at each subsequent reporting period. The Company does not control when Lilly will exercise its options for development and commercialization licenses. As a result, the Company cannot predict when it will recognize the related license revenue except that it will be within the term of the research license. The Company will recognize research services revenue and revenue from the delivery of cytotoxic agents as the related services and cytotoxic agents are delivered. No license revenue has been recognized related to this agreement through June 30, 2013 as the options to take development and commercialization licenses were not considered to be substantive and no development and commercialization licenses had been delivered at this time. Accordingly, the entire $20 million upfront payment is included in long-term deferred revenue at June 30, 2013. Other Collaborative Agreements In December 2004, the Company entered into a development and license agreement with a predecessor to Janssen Biotech (formerly known as Centocor), a wholly owned subsidiary of Johnson & Johnson. Under the terms of this agreement, Janssen was granted exclusive worldwide rights to develop and commercialize anticancer therapeutics that consist of the Company's maytansinoid cell-killing agent attached to an av integrin-targeting antibody that was developed by Janssen. Under the terms of the agreement, the Company received an upfront payment of $1 million upon execution of the agreement. In December 2007, the Company licensed from Janssen the exclusive, worldwide right to develop and commercialize a TAP compound, IMGN388, that consists of an av integrin-targeting antibody developed by them and one of the Company's maytansinoid cell-killing agents. This license reallocated the parties' respective responsibilities and financial obligations from the license referenced above. In November 2011, the Company announced its decision to discontinue development of IMGN388. During the first quarter of fiscal 2013, the 2007 license agreement was terminated with rights to the product candidate reverting back to Janssen. The remaining $241,000 of the $1 million upfront fee received from Janssen upon execution of the 2004 license agreement is included in long-term deferred revenue at June 30, 2013. Effective July 2011, Biogen Idec terminated its exclusive license to the Company's TAP technology to develop and commercialize therapeutic compounds to the target Cripto. This license was granted pursuant to the Development and License Agreement between the Company and Biogen Idec dated October 1, 2004. As a result of the termination, during the first quarter of fiscal 2012, the Company recognized the remaining $270,000 of the $1 million upfront fee received from Biogen Idec upon execution of the license which had been previously deferred.

Marketable Securities	12 Months Ended
Marketable Securities	Jun. 30, 2013
Marketable Securities
Marketable Securities	D. Marketable Securities As of June 30, 2013 and 2012, $195.0 million and $160.9 million, respectively, in cash and money market funds consisting principally of U.S. Government-issued securities and high quality, short-term commercial paper were classified as cash and cash equivalents. During fiscal year 2011, the Company sold the remaining marketable securities held in its investment portfolio at June 30, 2010, resulting in realized gains of $347,000 and realized losses of $(6,000). In 2013 and 2012, the Company had no realized losses or gains.

- Definition

The entire disclosure for investments in certain debt and equity securities.

+ References

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+ Details

Property and Equipment

12 Months Ended

Jun. 30, 2013

Property and Equipment

Property and Equipment

E. Property and Equipment

Property and equipment consisted of the following at June 30, 2013 and 2012 (in thousands):

	June 30,

	2013			2012
Leasehold improvements	$	26,777		$	25,661
Machinery and equipment		14,741			13,808
Computer hardware and software		4,894			4,168
Furniture and fixtures		1,540			1,315
Assets under construction		814			660

	$	48,766		$	45,612
Less accumulated depreciation		(37,983	)		(33,979	)

Property and equipment, net	$	10,783		$	11,633

Depreciation expense was approximately $4.6 million, $4.6 million and $4.9 million for the years ended June 30, 2013, 2012 and 2011, respectively.

- Definition

The entire disclosure for long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software. This disclosure may include property plant and equipment accounting policies and methodology, a schedule of property, plant and equipment gross, additions, deletions, transfers and other changes, depreciation, depletion and amortization expense, net, accumulated depreciation, depletion and amortization expense and useful lives, income statement disclosures, assets held for sale and public utility disclosures.

+ References+ Details

Income Taxes

12 Months Ended

Jun. 30, 2013

Income Taxes

Income Taxes

F. Income Taxes

The difference between the Company's expected tax benefit, as computed by applying the U.S. federal corporate tax rate of 34% to loss before the benefit for income taxes, and actual tax is reconciled in the following chart (in thousands):

	Year Ended June 30,

	2013			2012			2011
Loss before income tax expense	$	(72,811	)	$	(73,319	)	$	(58,274	)

Expected tax benefit at 34%	$	(24,756	)	$	(24,928	)	$	(19,813	)
Permanent differences		1,540			1,469			—
State tax benefit net of federal benefit		(3,921	)		(4,204	)		(1,815	)
Increase in valuation allowance, net		25,192			26,574			16,410
Expired loss and credit carryforwards		1,945			1,089			5,610
Other		—			—			(392	)

Benefit for income taxes	$	—		$	—		$	—

At June 30, 2013, the Company has net operating loss carryforwards of approximately $329.5 million available to reduce federal taxable income, if any, that expire in 2014 through 2033 and $187.4 million available to reduce state taxable income, if any, that expire in fiscal 2014 through fiscal 2033. Included in the federal and state carryforwards is $18.5 million and $15.8 million, respectively, related to deductions from the exercise of stock options and the related tax benefit will result in an increase in additional paid-in capital if and when realized through a reduction of taxes paid in cash. The Company also has federal and state research tax credits of approximately $14.8 million available to offset federal and state income taxes, which expire beginning in fiscal 2014. Due to the degree of uncertainty related to the ultimate use of the loss carryforwards and tax credits, the Company has established a valuation allowance to fully reserve these tax benefits.

Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of the Company's deferred tax assets as of June 30, 2013 and 2012 are as follows (in thousands):

	June 30,

	2013			2012
Net operating loss carryforwards	$	121,937		$	98,601
Research and development tax credit carryforwards		12,806			10,393
Property and other intangible assets		2,077			1,486
Deferred revenue		25,484			28,325
Stock-based compensation		5,759			3,302
Deferred lease incentive		4,771			5,100
Other liabilities		508			512

Total deferred tax assets	$	173,342		$	147,719
Valuation allowance		(173,342	)		(147,719	)

Net deferred tax assets	$	—		$	—

The valuation allowance increased by $25.6 million during 2013 due primarily to the additional net loss recognized during the year, partially offset by the expiration of net operating loss carryforwards.

Utilization of the NOL and R&D credit carryforwards may be subject to a substantial annual limitation due to ownership change limitations that have occurred previously or that could occur in the future as provided by Section 382 of the Internal Revenue Code of 1986, as well as similar state and foreign provisions. These ownership changes may limit the amount of NOL and R&D credit carry forwards that can be utilized annually to offset future taxable income and tax, respectively. In general, an ownership change, as defined by Section 382, results from transactions increasing the ownership of certain shareholders or public groups in the stock of a corporation by more than 50 percentage points over a three-year period. Since the Company's formation, it has raised capital through the issuance of capital stock on several occasions (both pre and post initial public offering) which, combined with the purchasing shareholders' subsequent disposition of those shares, may have resulted in a change of control, as defined by Section 382, or could result in a change of control in the future upon subsequent disposition. The Company has not currently completed a study to assess whether a change of control has occurred or whether there have been multiple changes of control since its formation due to the significant complexity, costs associated with such study and the possibility that there could be additional changes in control in the future. If the Company has experienced a change of control at any time since its formation, utilization of its NOL or R&D credit carry forwards would be subject to an annual limitation under Section 382 which is determined by first multiplying the value of the Company's stock at the time of the ownership change by the applicable long-term tax-exempt rate, and then could be subject to additional adjustments, as required. Any limitation may result in expiration of a portion of the NOL or R&D credit carry forwards before utilization. Further, until a study is completed and any limitation known, no amounts are being presented as an uncertain tax position. The Company does not expect to have any taxable income for at least the next several years.

Interest and penalties related to the settlement of uncertain tax positions, if any, will be reflected in income tax expense. The Company did not recognize any interest and penalties associated with unrecognized tax benefits in the accompanying consolidated financial statements. The Company does not expect any material changes to the unrecognized benefits within 12 months of the reporting date. Due to existence of the valuation allowance, future changes in the Company's unrecognized tax benefits will not impact our effective tax rate. The Company's loss carryforwards are subject to adjustment by state and federal taxing authorities, commencing when those losses are utilized to reduce taxable income.

Included in other (expense) income, net for the fiscal year ended June 30, 2011 is $1.2 million of federal grant funding the Company was awarded under the Patient Protection and Affordable Care Act of 2010 to develop new anticancer therapies.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

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+ Details

Capital Stock

12 Months Ended

Jun. 30, 2013

Capital Stock

Capital Stock

G. Capital Stock

Sale of Common Stock

On May 19, 2011, the Company filed a Registration Statement on Form S-3 with the Securities and Exchange Commission. Pursuant to the shelf registration statement, in May 2011 and June 2011, the Company issued and sold a total of 7,800,000 shares of its common stock at $12.00 per share through a public offering resulting in gross proceeds of $93.6 million. Pursuant to the shelf registration statement filed in May 2011, in July 2012, the Company issued and sold a total of 6,250,000 shares of its common stock at $16.00 per share through a public offering resulting in gross proceeds of $100 million.

Common Stock Reserved

At June 30, 2013, the Company has reserved 12.57 million shares of authorized common stock for the future issuance of shares under the 2006 Plan and the 2004 Director Plan. See "Stock-Based Compensation" in Note B for a description of the 2006 Plan and the Former Plan and Note G below for a description of the 2004 Director Plan.

Stock Options

As of June 30, 2013, the 2006 Plan was the only employee share-based compensation plan of the Company. During the year ended June 30, 2013, holders of options issued under the 2006 Plan and the Former Plan exercised their rights to acquire an aggregate of 666,000 shares of common stock at prices ranging from $2.91 to $15.20 per share. The total proceeds to the Company from these option exercises were approximately $4.0 million.

The Company granted options with an exercise price equal to the fair market value of the common stock on the date of such grant. The following options and their respective weighted- average exercise prices per share were exercisable at June 30, 2013, 2012 and 2011:

		Weighted- Average Exercise Price

June 30, 2013	4,202	$	7.97
June 30, 2012	3,416	$	6.34
June 30, 2011	3,834	$	5.25

2001 Non-Employee Director Stock Plan

In November 2001, the Company's shareholders approved the establishment of the 2001 Non-Employee Director Stock Plan, or the 2001 Director Plan, and 50,000 shares of common stock to be reserved for grant thereunder. The 2001 Director Plan provided for the granting of awards to Non-Employee Directors and, at the election of Non-Employee Directors, to have all or a portion of their awards in the form of cash, stock, or stock units. All stock or stock units are immediately vested. The number of stock or stock units issued was determined by the market value of the Company's common stock on the last date of the Company's fiscal quarter for which the services are rendered. The 2001 Director Plan was administered by the Board of Directors which was authorized to interpret the provisions of the 2001 Director Plan, determine which Non-Employee Directors would be granted awards, and determine the number of shares of stock for which a stock right will be granted. The 2001 Director Plan was replaced in 2004 by the 2004 Non-Employee Director Compensation and Deferred Share Unit Plan.

During the years ended June 30, 2013, 2012 and 2011, the Company recorded approximately $(1,000), $29,000, and $44,000 in (expense reduction) compensation expense, respectively, related to approximately 6,000, 6,000, and 15,000 stock units outstanding, respectively, under the 2001 Director Plan. The value of the stock units is adjusted to market value at each reporting period. No stock units have been issued under the 2001 Plan subsequent to June 30, 2004. Pursuant to the 2001 Plan, in November 2011, the Company paid a retiring director approximately $115,000 to settle outstanding stock units.

2004 Non-Employee Director Compensation and Deferred Share Unit Plan

In June 2004, the Board of Directors approved the establishment of the 2004 Non-Employee Director Compensation and Deferred Share Unit Plan, or the 2004 Director Plan. The 2004 Director Plan provided for the compensation of Non-Employee Directors, awarding their annual retainers in the form of deferred share units, and, at their discretion, to have all or a portion of their other compensation such as meeting fees in the form of cash or deferred share units. The deferred share units for annual retainers vested one-twelfth monthly over the next year after the award; other deferred share units vested immediately upon issuance. The number of deferred share units issued was determined by the market value of the Company's common stock on the last date of the Company's fiscal year prior to the fiscal year for which services were rendered. The deferred share units were to be paid out in cash to each non-employee director based upon the market value of the Company's common stock on the date of such director's retirement from the Board of Directors of the Company. The 2004 Director Plan was administered by the Board of Directors.

The 2004 Director Plan was amended on September 5, 2006. Under the terms of the amended 2004 Director Plan, the redemption amount of deferred share units will be paid in shares of common stock of the Company under the 2006 Plan in lieu of cash. As a result of the change in payout structure, the value of the vested awards was transferred to additional paid-in capital as of the modification date and the total value of the awards, as calculated on the modification date, was expensed over the remainder of the vesting period. Accordingly, the value of the share units is fixed and will no longer be adjusted to market value at each reporting period. In addition, the amended 2004 Director Plan changed the vesting for annual retainers to take place quarterly over the three years after the award and the number of deferred share units awarded for all compensation is now based on the market value of the Company's common stock on the date of the award.

Compensation Policy for Non-Employee Directors

On September 16, 2009, the Board adopted a new Compensation Policy for Non-Employee Directors, which superseded the 2004 Plan and made certain changes to the compensation of its non-employee directors. The policy was amended on November 11, 2009 to provide that, whenever the Board has a non-employee Chairman in lieu of a Lead Director, the cash payment for the non-employee Chairman of the Board shall be the same as the cash compensation that would otherwise have been payable to the Lead Director. Effective November 12, 2009, non-employee directors became entitled to receive annual meeting fees and committee fees under the new policy. The new policy made changes to the equity portion of the non-employee director compensation, but left the cash portion unchanged. Effective November 11, 2009, non-employee directors became entitled to receive deferred stock units under the new policy as follows:

•

New non-employee directors will be initially awarded a number of deferred stock units having an aggregate market value of $65,000, based on the closing price of our common stock on the date of their initial election to the Board. These awards will vest quarterly over three years from the date of grant, contingent upon the individual remaining a director of ImmunoGen as of each vesting date.

•

On the first anniversary of a non-employee director's initial election to the Board, such non-employee director will be awarded a number of deferred stock units having an aggregate market value of $30,000, based on the closing price of our common stock on such date of grant and pro-rated based on the number of whole months remaining between the first day of the month in which such grant date occurs and the first October 31 following the grant date. These awards will generally vest quarterly over approximately the period from the grant date to the first November 1 following the grant date, contingent upon the individual remaining a director of ImmunoGen as of each vesting date.

•

Thereafter, non-employee directors in general will be annually awarded a number of deferred stock units having an aggregate market value of $30,000, based on the closing price of our common stock on the date of our annual meeting of shareholders. These awards will vest quarterly over approximately one year from the date of grant, contingent upon the individual remaining a director of ImmunoGen as of each vesting date.

As with the 2004 Plan, vested deferred stock units are redeemed on the date a director ceases to be a member of the Board, at which time such director's deferred stock units will be settled in shares of our common stock issued under our 2006 Plan at a rate of one share for each vested deferred stock unit then held. Any deferred stock units that remain unvested at that time will be forfeited. The new policy provides that all unvested deferred stock units will automatically vest immediately prior to the occurrence of a change of control, as defined in the 2006 Plan. Pursuant to the Compensation Policy for Non-Employee Directors, in November 2011, the Company issued two retiring directors an aggregate 46,298 shares of common stock of the Company to settle outstanding deferred share units.

In connection with the adoption of the new compensation policy, the Board also amended the 2004 Plan as follows:

•

All unvested deferred stock awards (other than any unvested initial awards) were vested in full on September 16, 2009 unless the date such deferred stock units were credited to the non-employee director was less than one year prior to September 16, 2009, in which case such unvested deferred stock units will vest on the first anniversary of the date such deferred stock units were credited to the non-employee director.

•

All unvested deferred stock awards will automatically vest immediately prior to the occurrence of a change of control.

On September 22, 2010, the Board revised the Compensation Policy for Non-Employee Directors to provide that, in addition to the compensation they received previously, they would also become entitled to receive stock option awards having a grant date fair value of $30,000, determined using the Black-Scholes option pricing model measured on the date of grant, which would be the date of the annual meeting of shareholders. These options will vest quarterly over approximately one year from the date of grant. Any new directors will receive a pro-rated award, depending on their date of election to the Board. The directors received a total of 41,805, 33,187 and 49,688 options in fiscal years 2013, 2012 and 2011, respectively, and the related compensation expense is included in the amounts discussed in the "Stock-based Compensation" section of footnote B above.

Pursuant to the Compensation Policy for Non-Employee Directors and the 2004 Director Plan, as amended, the Company recorded approximately:

•

$351,000 in compensation expense during the year ended June 30, 2013 related to the issuance of 26,000 deferred share units and 251,000 deferred share units previously issued under the 2004 Director Plan;

•

$314,000 in compensation expense during the year ended June 30, 2012 related to the issuance of 33,000 deferred share units and 264,000 deferred share units previously issued under the 2004 Director Plan; and

•

$326,000 in compensation expense during the year ended June 30, 2011 related to the issuance of 39,000 deferred share units and 225,000 deferred share units previously issued under the 2004 Director Plan.

Commitments and Contingencies

12 Months Ended

Jun. 30, 2013

Commitments and Contingencies

Commitments and Contingencies

H. Commitments and Contingencies

Leases

Effective July 27, 2007, the Company entered into a lease agreement with Intercontinental Fund III for the rental of approximately 89,000 square feet of laboratory and office space at 830 Winter Street, Waltham, MA. The Company uses this space for its corporate headquarters and other operations. The initial term of the lease is for twelve years with an option for the Company to extend the lease for two additional terms of five years. The Company is required to pay certain operating expenses for the leased premises subject to escalation charges for certain expense increases over a base amount. The Company entered into a sublease in December 2009 for 14,100 square feet of this space in Waltham through January 2015, with the sublessee having a conditional option to extend the term for an additional two years.

Effective April 2012, the Company entered into a sublease agreement for the rental of 7,310 square feet of laboratory and office space at 830 Winter Street, Waltham, MA from Histogenics Corporation. The initial term of the sublease is for three years with a conditional option for the Company to extend the lease through October 2017. The Company is required to pay certain operating expenses for the leased premises subject to escalation charges for certain expense increases over a base amount.

As part of the 2007 lease agreement, the Company received a construction allowance of up to approximately $13.3 million to build out laboratory and office space to the Company's specifications. After completion, the Company had recorded $12.0 million of leasehold improvements under the construction allowance. The Company received $10.8 million from the landlord and paid out the same amount towards these leasehold improvements. The remaining balance of the improvements was paid directly by the landlord. The lease term began on October 1, 2007, when the Company obtained physical control of the space in order to begin construction.

The Company also leases manufacturing and office space at 333 Providence Highway, Norwood, MA under an agreement through 2018 with an option to extend the lease for an additional term of five years. The Company is required to pay certain operating expenses for the leased premises subject to escalation charges for certain expense increases over a base amount.

Effective April 2013, the Company entered into a lease agreement with River Ridge Limited Partnership for the rental of 7,507 square feet of additional office space at 100 River Ridge Drive, Norwood, MA. The initial term of the lease is for five years and two months commencing in July 2013 with an option for the Company to extend the lease for an additional term of five years. The Company is required to pay certain operating expenses for the leased premises subject to escalation charges for certain expense increases over a base amount.

Facilities rent expense, net of sublease income, was approximately $4.8 million, $4.8 million and $4.6 million during fiscal years 2013, 2012 and 2011, respectively.

As of June 30, 2013, the minimum rental commitments, including real estate taxes and other expenses, for the next five fiscal years and thereafter under the non-cancelable operating lease agreements discussed above are as follows (in thousands):


2013	$	6,636
2014		6,780
2015		6,549
2016		6,624
2017		6,831
Thereafter		10,029

Total minimum lease payments	$	43,449
Total minimum rental income from subleases		(1,088	)

Total minimum lease payments, net	$	42,361

Collaborations

The Company is contractually obligated to make potential future success-based regulatory milestone payments in conjunction with certain collaborative agreements. These payments are contingent upon the occurrence of certain future events and, given the nature of these events, it is unclear when, if ever, the Company may be required to pay such amounts. Further, the timing of any future payment is not reasonably estimable. During the first quarter of fiscal 2013, the Company's license agreement with Janssen Biotech was terminated and, accordingly, the Company is no longer obligated to make $41.0 million of potential future success-based milestone and third-party payments under such agreement. As of June 30, 2013, the maximum amount that may be payable in the future under the Company's current collaborative agreements is $2.0 million, $1.4 million of which is reimbursable by a third party under a separate agreement.

Litigation

The Company is not party to any material litigation.

- Definition

The entire disclosure for commitments and contingencies.

+ References

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-Name FASB Interpretation (FIN)

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+ Details

Employee Benefit Plans	12 Months Ended
Employee Benefit Plans	Jun. 30, 2013
Employee Benefit Plans
Employee Benefit Plans	I. Employee Benefit Plans The Company has a deferred compensation plan under Section 401(k) of the Internal Revenue Code (the 401(k) Plan). Under the 401(k) Plan, eligible employees are permitted to contribute, subject to certain limitations, up to 100% of their gross salary and the Company's matching contribution is 50% of the first 6% of the eligible employees' contributions. In fiscal years 2013, 2012 and 2011, the Company's contributions to the 401(k) Plan totaled approximately $593,000, $548,000, and $467,000, respectively.

- Definition

The entire disclosure for pension and other postretirement benefits.

+ References

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-Number 132R

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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+ Details

Quarterly Financial Information (Unaudited)

12 Months Ended

Jun. 30, 2013

Quarterly Financial Information (Unaudited)

Quarterly Financial Information (Unaudited)

J. Quarterly Financial Information (Unaudited)

	Fiscal Year 2013

	First Quarter Ended September 30, 2012			Second Quarter Ended December 31, 2012			Third Quarter Ended March 31, 2013			Fourth Quarter Ended June 30, 2013
	(In thousands, except per share data)
Revenues:
License and milestone fees	$	933		$	429		$	22,010		$	855
Research and development support		1,377			2,036			2,257			2,203
Clinical materials revenue		1,781			147			734			181
Royalty revenue		—			—			—			592

Total revenues		4,091			2,612			25,001			3,831
Expenses:
Research and development		23,700			21,656			21,318			20,399
General and administrative		5,639			5,464			4,995			5,373

Total expenses		29,339			27,120			26,313			25,772

Loss from operations		(25,248	)		(24,508	)		(1,312	)		(21,941	)
Other income (expense), net		56			115			(39	)		66

Net loss	$	(25,192	)	$	(24,393	)	$	(1,351	)	$	(21,875	)

Basic and diluted net loss per common share	$	(0.30	)	$	(0.29	)	$	(0.02	)	$	(0.26	)

	Fiscal Year 2012

	First Quarter Ended September 30, 2011			Second Quarter Ended December 31, 2011			Third Quarter Ended March 31, 2012			Fourth Quarter Ended June 30, 2012
	(In thousands, except per share data)
Revenues:
License and milestone fees	$	1,187		$	6,025		$	999		$	950
Research and development support		1,068			945			1,320			1,184
Clinical materials reimbursement		281			647			933			818

Total revenues		2,536			7,617			3,252			2,952
Expenses:
Research and development		17,161			15,559			16,933			19,539
General and administrative		4,841			4,834			5,021			5,726

Total expenses		22,002			20,393			21,954			25,265

Loss from operations		(19,466	)		(12,776	)		(18,702	)		(22,313	)
Other income, net		(17	)		23			33			(101	)

Net loss	$	(19,483	)	$	(12,753	)	$	(18,669	)	$	(22,414	)

Basic and diluted net loss per common share	$	(0.26	)	$	(0.17	)	$	(0.24	)	$	(0.29	)

- Definition

The entire disclosure for the quarterly financial data in the annual financial statements. The disclosure may include a tabular presentation of financial information for each fiscal quarter for the current and previous year, including revenues, gross profit, income or loss before extraordinary items and earnings per share data. It also includes an indication if the information in the note is unaudited, comments on the aggregate effect of year-end adjustments, and an explanation of matters or transactions that affect comparability or are pertinent to an understanding of the information furnished.

+ References+ Details

SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS

12 Months Ended

Jun. 30, 2013

SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS

SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS

SCHEDULE II—VALUATION AND QUALIFYING ACCOUNTS
(In thousands)

COLUMN A—DESCRIPTION	COLUMN B		COLUMN C— ADDITIONS		COLUMN D			COLUMN E

Inventory Valuation Allowance	Balance at Beginning of Period		Charged to Costs and Expenses		Use of Zero Value Inventory			Balance at End of Period
Year End June 30, 2013	$	1,291	$	798	$	(1,279	)	$	810
Year End June 30, 2012	$	1,993	$	786	$	(1,488	)	$	1,291
Year End June 30, 2011	$	939	$	1,664	$	(610	)	$	1,993

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Jun. 30, 2013

Summary of Significant Accounting Policies

Principles of Consolidation

Principles of Consolidation

Use of Estimates

Use of Estimates

Subsequent Events

Subsequent Events

Revenue Recognition

Revenue Recognition

At June 30, 2013, the Company had the following two types of agreements with the parties identified below:

•

Development and commercialization licenses to use the Company's TAP technology and/or certain other intellectual property to develop compounds to a specified target antigen (referred to as development and commercialization licenses, as distinguished from the Company's right-to-test agreements described elsewhere):

- Amgen (three exclusive single-target licenses; one non-exclusive single-target license)
  
  Bayer HealthCare (one exclusive single-target license)
  
  Biotest (one exclusive single-target license)
  
  Novartis (one license to two related targets, one target on an exclusive basis and the second target on a non-exclusive basis)
  
  Roche, through its Genentech unit (five exclusive single-target licenses)
  
  Sanofi (exclusive license to multiple individual targets)
•

Option/research agreement for a defined period of time to secure development and commercialization licenses to use the Company's TAP technology to develop anticancer compounds to specified targets on established terms (referred to herein as right-to-test agreements):

- Sanofi
  
  Novartis
  
  Lilly

There are no performance, cancellation, termination or refund provisions in any of the arrangements that contain material financial consequences to the Company.

Development and Commercialization Licenses

Right-to-Test Agreements

Inventory

Inventory

Inventory at June 30, 2013 and 2012 is summarized below (in thousands):

	June 30,

	2013		2012
Raw materials	$	75	$	129
Work in process		628		1,159

Total	$	703	$	1,288

The Company capitalizes raw material as inventory upon receipt and accounts for the raw material inventory as follows:

a)

to the extent that the Company has up to twelve months of firm, fixed orders and/or projections from its collaborators, the Company capitalizes the value of raw materials that will be used in the production of conjugate subject to these firm, fixed orders and/or projections;

b)

the Company considers more than a twelve month supply of raw materials that is not supported by firm, fixed orders and/or projections from its collaborators to be excess and establishes a reserve to reduce to zero the value of any such excess raw material inventory with a corresponding charge to research and development expense; and

c)

the Company also considers any other external factors and information of which it becomes aware and assesses the impact of such factors or information on the net realizable value of the raw material inventory at each reporting period.

During fiscal years 2013, 2012 and 2011, the Company obtained additional amounts of DMx from its supplier which yielded more material than would be required by the Company's collaborators over the next twelve months and as a result, the Company recorded $798,000, $748,000 and $1.7 million respectively, of charges to research and development expense related to raw material inventory identified as excess. The Company also recorded $38,000 as research and development expense to write down certain raw material inventory to its net realizable value in fiscal year 2012. No similar charges were recorded during fiscal years 2013 and 2011. Increases in the Company's on-hand supply of raw materials, or a reduction to the Company's collaborators' projections, could result in significant changes in the Company's estimate of the net realizable value of such raw material inventory. Reductions in collaborators' projections could indicate that the Company has excess raw material inventory and the Company would then evaluate the need to record write-downs as charges to research and development expense.

Unbilled Revenue

Unbilled Revenue

The majority of the Company's unbilled revenue at June 30, 2013 and 2012 represents research funding earned based on actual resources utilized under the Company's various collaborator agreements.

Restricted Cash

Restricted Cash

Restricted cash at June 30, 2013 and 2012 are cash balances securing irrevocable letters of credit required for security deposits for the Company's leased facilities.

Other Accrued Liabilities

Other Accrued Liabilities

Other accrued liabilities consisted of the following at June 30, 2013 and 2012 (in thousands):

	June 30,

	2013		2012
Accrued contract payments	$	2,406	$	1,773
Accrued clinical trial costs		1,849		865
Accrued professional services		678		677
Accrued employee benefits		411		351
Accrued public reporting charges		179		208
Other current accrued liabilities		526		715

Total	$	6,049	$	4,589

Research and Development Expenses

Research and Development Expenses

Income Taxes

Income Taxes

Financial Instruments and Concentration of Credit Risk

Financial Instruments and Concentration of Credit Risk

Cash Equivalents

Cash Equivalents

Fair Value of Financial Instruments

Fair Value of Financial Instruments

•

Level 1—Quoted prices in active markets for identical assets or liabilities.

•

Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

•

Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

	Fair Value Measurements at June 30, 2013 Using

			Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	Total		(Level 1)		(Level 2)		(Level 3)
Cash, cash equivalents and restricted cash	$	197,191	$	197,191	$	—	$	—

	$	197,191	$	197,191	$	—	$	—

	Fair Value Measurements at June 30, 2012 Using

			Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	Total		(Level 1)		(Level 2)		(Level 3)
Cash, cash equivalents and restricted cash	$	163,488	$	163,488	$	—	$	—

	$	163,488	$	163,488	$	—	$	—

The fair value of the Company's cash equivalents is based primarily on quoted prices from active markets.

Property and Equipment

Property and Equipment

Property and equipment are stated at cost. The Company provides for depreciation based upon expected useful lives using the straight-line method over the following estimated useful lives:


Machinery and equipment		5 years
Computer hardware and software		3 years
Furniture and fixtures		5 years
Leasehold improvements		Shorter of remaining lease term or 7 years

Impairment of Long-Lived Assets

Impairment of Long-Lived Assets

Computation of Net Loss Per Common Share

Computation of Net Loss Per Common Share

	June 30,

	2013		2012		2011
Options outstanding to purchase common stock and unvested restricted stock		7,703		6,442		6,491
Common stock equivalents under treasury stock method		2,149