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

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.

The Company has evaluated all events or transactions that occurred after December 31, 2021 up through the date the Company issued these financial statements. On February 14, 2022, the Company and Eli Lilly and Company (“Lilly”) entered into a license agreement, pursuant to which the Company granted Lilly worldwide exclusive rights to research, develop, and commercialize ADCs based on the Company’s novel camptothecin technology. Under the terms of the license agreement, the Company is entitled to receive an upfront payment of $13 million, reflecting initial targets selected by Lilly, and up to an additional $32.5 million if Lilly selects the maximum number of additional targets over the four year-period following the effective date of the license agreement. In addition, Lilly will be obligated to pay the Company, on a target-by-target basis, development, regulatory, and commercial milestones. In total, the Company could earn up to $1.7 billion in target selection fees and development, regulatory, and commercial milestones if all targets are selected and all milestones are realized. The Company is also eligible to receive tiered royalties, on a product-by-product basis, as a percentage of worldwide annual net sales by Lilly, based on certain net sales thresholds. The Company did not have any other material subsequent events.

The Company enters into licensing and development agreements with collaborators for the development of ADCs. The terms of these agreements contain multiple promised goods and services which may include (i) licenses, or options to obtain licenses, to the Company’s ADC technology, (ii) rights to future technological improvements, (iii) technology transfer services and other activities to be performed on behalf of the collaborative partner, and (iv) delivery of cytotoxic agents and/or the manufacture of preclinical and clinical materials for the collaborative partner. Payments to the Company under these agreements may include upfront fees, option fees, exercise fees, payments for services, payments for preclinical or clinical materials, payments based upon the achievement of certain milestones, and royalties on product sales. The Company follows the provisions of ASC 606, Revenue from Contracts with Customers, in accounting for these agreements.

Revenue is recognized when a customer obtains control of promised goods or services in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. In determining the appropriate amount of revenue to be recognized as it fulfills its obligations under the agreements, the Company performs the following five steps: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations, including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations; and (v) recognition of revenue when or as the Company satisfies each performance obligation.

The Company only applies the five-step model to contracts when it is probable that the Company will collect the consideration to which it is entitled in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations based on its assessment of whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when or as the performance obligation is satisfied.

The Company exercises judgment in assessing those promised goods and services that are distinct and thus representative of performance obligations. To the extent the Company identifies multiple performance obligations in a contract, the Company must develop assumptions that require judgment to determine the estimated standalone selling price for each performance obligation in order to allocate the transaction price among the identified performance obligations. These judgments and assumptions are discussed in further detail below.

At December 31, 2021, the Company had the following types of material agreements with the parties identified below:

Bayer (one exclusive single-target license)

CytomX (two exclusive single-target licenses)

Debiopharm (one exclusive single-compound license)

Fusion Pharmaceuticals (one exclusive single-target license)

Hangzhou Zhongmei Huadong Pharmaceutical Co., Ltd. (one territory-specific exclusive single-compound license)

Novartis (five exclusive single-target licenses)

Oxford BioTherapeutics/Menarini (one exclusive single-target license sublicensed from Amgen)

Roche, through its Genentech unit (five exclusive single-target licenses)

Viridian (one exclusive single-target license)

●

Collaboration and license agreement to co-develop and co-commercialize a specified anticancer compound on established terms:

MacroGenics

During the year ended December 31, 2020, pursuant to notices received, the exclusive development and commercialization licenses granted to each of Biotest and Takeda and the collaboration and option agreement with Jazz were terminated.

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 obligations under a development and commercialization license agreement generally include the license to the Company’s ADC technology with respect to a specified antigen target or compound and may also include obligations related to rights to future technological improvements and other activities to be performed on behalf of 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 earn payments upon the achievement of certain milestones and royalty payments, generally until the later of the last applicable patent expiration or a fixed period of years after product launch. Royalty rates may vary over the royalty term depending on the Company’s intellectual property rights and/or the presence of comparable competing products. In the case of Debiopharm, no royalties will be received. In certain instances, the Company may also provide cytotoxic agents and/or clinical materials or other services in addition to the development and commercialization licenses. For example, the Company may provide technology transfer services in connection with the out-licensing of product candidates initially developed by the Company and may also 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 certain services, achieve milestones, or become liable for royalty payments.

In determining the performance obligations for these arrangements, management evaluates whether the license is distinct and has significant standalone functionality either alone or with other readily available resources 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 ADC technology research expertise and ADC manufacturing capabilities in the general marketplace and whether technological improvements are required for the continued functionality of the license. If the license to the Company’s intellectual property is determined to be distinct, the Company recognizes revenues from non-refundable, upfront fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. If the license is not distinct, the license is combined with other goods or services into a single performance obligation and revenue is recognized over time.

The Company estimates the standalone selling prices of the license and all other performance obligations 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 ADC technology, the Company’s pricing practices and pricing objectives, the likelihood that technological improvements will be made, and, if made, will be used by the Company’s collaborators, and the nature of the other services to be performed on behalf of its collaborators and market rates for similar services.

The Company recognizes revenue related to technology transfer activities and other services as the services are performed. The Company is generally compensated for these activities at negotiated rates that are consistent with what other third parties would charge. The Company records amounts recognized for services performed as a component of research and development support revenue.

The Company may also provide cytotoxic agents and/or preclinical and clinical materials (drug substance/drug product) to its collaborators at negotiated prices generally consistent with what other third parties would charge. The Company recognizes revenue on cytotoxic agents and/or preclinical and clinical materials when control transfers to the collaborator as a component of research and development support revenue.

The Company recognizes revenue related to the rights to future technological improvements over the estimated term of the applicable license.

The Company’s development and commercialization license agreements have milestone payments which for reporting purposes are aggregated into two categories: (i) development and regulatory milestones, and (ii) 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 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 arrangement, the Company evaluates any development and regulatory milestone payments to determine whether the milestone is considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price to be allocated; otherwise, such amounts are considered constrained and excluded from the transaction price. As part of its evaluation of the constraint, the Company considers numerous factors, including whether the achievement of the milestone is outside the control of the Company and contingent upon the future success of clinical trials, the collaborator’s efforts, or the receipt of regulatory approval. At the end of each subsequent reporting period, the Company re-evaluates the probability of achievement of such development or regulatory milestones and any related constraint, and if necessary, adjusts the estimate of the transaction price. In addition, the Company evaluates whether the achievement of each milestone specifically relates to the Company’s efforts to satisfy a performance obligation or transfer a distinct good or service within a performance obligation. If the achievement of a milestone is considered a direct result of the Company’s efforts to satisfy a performance obligation or transfer a distinct good or service and the receipt of the payment is based upon the achievement of the milestone, the associated milestone value is allocated to that distinct good or service. If the milestone payment is not specifically related to the Company’s effort to satisfy a performance obligation or transfer a distinct good or service, the amount is allocated to all performance obligations using the relative standalone selling price method. Amounts allocated to a satisfied performance obligation are recognized as revenue, or as a reduction of revenue, in the period in which the transaction price changes.

For development and commercialization license agreements that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied) in accordance with the royalty recognition constraint. Under the Company’s development and commercialization license agreements, except for the Debiopharm license, the Company receives royalty payments based upon its licensees’ net sales of covered products. Generally, under the development and commercialization agreements, the Company receives royalty reports and payments from its licensees approximately one quarter in arrears. The Company estimates the amount of royalty revenue to be recognized based on historical and forecasted sales and/or sales information from its licensees if available.

Collaboration and Option Agreements/Right-to-Test Agreements

The Company’s right-to-test agreements provide collaborators the right to test the Company’s ADC technology for a defined period of time through a research, or right-to-test, license. Under both right-to-test agreements and collaboration and option agreements, collaborators may (a) “take” options, for a defined period of time, to specified targets and (b) 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 the opt-in 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”), (iii) after providing services at the collaborator’s request at negotiated prices, which are generally consistent with what other third parties would charge, or (iv) upon some combination of all of these fees.

The accounting for collaboration and option agreements and right-to-test agreements is dependent on the nature of the options granted to the collaborative partner. Options are considered distinct performance obligations if they provide a collaborator with a material right. Factors that are considered in evaluating whether options convey a material right 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 fair value of the licenses, and the additional financial commitments or economic penalties imposed on the collaborator as a result of exercising the options.

If the Company concludes that an option provides the customer a material right, and therefore is a separate performance obligation, the Company then determines the estimated standalone selling price of the option using the following inputs: (a) estimated fair value of the license underlying each option, (b) the amount the partner would pay to exercise the option to obtain the license, and (c) probability of exercise.

The Company does not 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.

Upfront payments on development and commercialization licenses may be recognized upon delivery of the license if facts and circumstances dictate that the license is distinct from the other promised goods and services.

In determining whether a collaboration and option agreement is within the scope of ASC 808, Collaborative Arrangements, management evaluates the level of involvement of both companies in the development and commercialization of the products to determine if both parties are active participants and if both parties are exposed to risks and rewards dependent on the commercial success of the licensed products. If the agreement is determined to be within the scope of ASC 808 and not representative of a vendor-customer relationship, the Company segregates the research and development activities and the related cost sharing arrangement. Payments made by the Company for such activities are recorded as research and development expense and reimbursements received from the partner are recognized as an offset to research and development expense.

Transaction Price Allocated to Remaining Performance Obligations

Deferred revenue under ASC 606 represents the portion of the transaction price received under various contracts for which work has not been performed (or has been partially performed) and includes unexercised contract options that are considered material rights. As of December 31, 2021, the aggregate amount of the transaction price allocated to remaining performance obligations comprising deferred revenue was $92.1 million. The Company expects to recognize revenue on approximately 48%, 41%, and 11% of the remaining performance obligations over the next 12 months, 13 to 60 months, and 61 to 120 months, respectively, however, it does not control when or if any collaborator will terminate existing development and commercialization licenses.

Contract Balances from Contracts with Customers

The following tables present changes in the Company’s contract assets and contract liabilities during the years ended December 31, 2021 and 2020 (in thousands):


	Balance at								Balance at
Year ended December 31, 2021	December 31, 2020		Additions		Deductions		Impact of Netting		December 31, 2021
Contract asset	$	—	$	5,500	$	(2,500)	$	—	$	3,000
Contract liabilities (deferred revenue)	$	110,109	$	4,753	$	(22,794)	$	—	$	92,068



	Balance at								Balance at
Year ended December 31, 2020	December 31, 2019		Additions		Deductions		Impact of Netting		December 31, 2020
Contract asset	$	3,631	$	—	$	(8,000)	$	4,369	$	—
Contract liabilities (deferred revenue)	$	127,432	$	42,050	$	(63,742)	$	4,369	$	110,109

During the years ended December 31, 2021, 2020, and 2019 the Company recognized the following revenues as a result of changes in contract asset and contract liability balances in the respective periods (in thousands):


	Year Ended
	December 31,
	2021		2020		2019
Revenue recognized in the period from:
Amounts included in contract liabilities at the beginning of the period	$	22,765	$	61,872	$	14,817
Performance obligations satisfied in previous periods	$	5,500	$	—	$	12,672

Pursuant to the Company’s license agreement executed with Hangzhou Zhongmei Huadong Pharmaceutical Co., Ltd. (Huadong), upon delivery of clinical materials in 2021, the Company recorded $14.6 million of the $40.0 million upfront payment received and deferred in 2020 as license and milestone fee revenue. Additionally, in December 2021, the Company received a $5.0 million payment for a development milestone achieved pursuant to its agreement with Huadong, of which $1.8 million was recorded as license and milestone fee revenue in 2021 and $3.2 million was deferred and will be recorded as revenue, along with the remaining $25.4 million from the upfront license fee, upon delivery of clinical material in 2022. Also, during 2021, pursuant to its license agreement with Viridian, the Company recorded $2.5 million as license and milestone fee revenue related to a development milestone achieved in October 2021 and a contract asset of $3.0 million for a second probable development milestone. The Company also recorded $0.2

million as license and milestone fee revenue for delivery of certain materials to Viridian that had been previously deferred, $0.3 million of license and milestone fee revenue related to numerous collaborators’ rights to technological improvements that had been previously deferred, and recorded $7.7 million of previously deferred non-cash royalty revenue related to the sale of rights to KADCYLA royalties, further details of which can be found in Note E, “Liability Related to Sale of Future Royalties.” Lastly, pursuant to a research agreement, the Company received a $1.6 million upfront option fee that is included in deferred revenue at December 31, 2021.

During 2020, the Company recognized $60.5 million of previously deferred license revenue upon Jazz’s opt-out of its right to the last remaining license under the agreement and $3.2 million of upfront fees previously received from other partners, of which $1.4 million was included in contract liabilities at the beginning of 2020. As noted above, a $40.0 million upfront payment received in 2020 pursuant to a license agreement executed with Huadong was recorded as deferred revenue and none of this amount was recognized as revenue during 2020. Additionally, a contract asset of $3.6 million, net of $4.4 million in related contract liabilities, was recorded for two probable milestones in 2019 pursuant to license agreements with CytomX and Novartis, which were subsequently achieved and paid during 2020.

The Company recorded the following during the year ended December 31, 2019: (i) license and milestone fee revenue of $7.7 million for probable development milestones pursuant to license agreements with CytomX and Novartis, with another $0.3 million deferred which represents the amount allocated to future rights to technological improvements; a $3.6 million contract asset was recorded in December 2019 related to these probable milestones, net of a $4.4 million reduction in related contract liabilities; (ii) a $5.0 million regulatory milestone payment earned under its license agreement with Genentech, a member of Roche; the full amount of the milestone was recognized as revenue in the period as the amount allocated to future rights to technological improvements was not material; (iii) $14.5 million of previously deferred license revenue recognized upon the opt-out of the right to execute a license by Jazz; (iv) $65.2 million was recorded as deferred revenue as a result of a sale of the Company’s residual rights to receive royalty payments on commercial sales of KADCYLA^® (ado-trastuzumab emtansine) as discussed in Note F; and (v) $0.3 million of revenue previously deferred related to numerous collaborators’ rights to technological improvements. Additionally, $7.3 million of a $7.5 million upfront payment invoiced to CytomX pursuant to a license agreement executed in December 2019 was recorded as license and milestone fee revenue upon delivery of the license and $0.2 million was deferred until delivery of certain materials.

The timing of revenue recognition, billings, and cash collections results in billed receivables, unbilled receivables, contract assets, and contract liabilities on the consolidated balance sheets. When consideration is received, or such consideration is unconditionally due, from a customer prior to transferring goods or services to the customer under the terms of a contract, a contract liability is recorded (under the caption deferred revenue). Contract liabilities are recognized as revenue after control of the products or services is transferred to the customer and all revenue recognition criteria have been met.

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 December 31, 2021 or 2020. 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.

Cash and Cash Equivalents

All highly liquid financial instruments with maturities of three months or less when purchased are considered cash equivalents. As of December 31, 2021 and 2020, the Company held $478.8 million and $293.9 million, respectively, in cash and money market funds consisting principally of U.S. Government-issued securities and high quality, short-term commercial paper which were classified as cash and cash equivalents.

Non-cash Investing Activities

The Company had $0.2 million and $0.7 million of accrued capital expenditures as of December 31, 2021 and 2020, respectively, which have been treated as a non-cash investing activity and accordingly, not reflected in the consolidated statement of cash flows.

Fair Value of Financial Instruments

ASC 820, Fair Value Measurement, defines fair value, establishes a framework for measuring fair value in accordance with accounting principles generally accepted in the U.S., and provides for disclosures about fair value measurements. Fair value is defined under ASC 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 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 December 31, 2021 and 2020, the Company held certain assets that are required to be measured at fair value on a recurring basis. The following tables represent the fair value hierarchy for the Company’s financial assets measured at fair value on a recurring basis as of each date (in thousands):

Fair Value Measurements at December 31, 2021

Quoted Prices in

Significant

Active Markets for

Significant Other

Unobservable

Identical Assets

Observable Inputs

Inputs

Total

(Level 1)

(Level 2)

(Level 3)

Cash equivalents

460,298

—

Fair Value Measurements at December 31, 2020

Quoted Prices in

Significant

Active Markets for

Significant Other

Unobservable

Identical Assets

Observable Inputs

Inputs

Total

(Level 1)

(Level 2)

(Level 3)

Cash equivalents

194,525

—

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 receivable, contract assets, non-cash royalty receivable, prepaid and other current assets, accounts payable, accrued compensation, and other accrued liabilities approximate fair value due to their short-term nature. The gross carrying amount and estimated fair value of the convertible 4.5% senior notes was $2.1 million and $4.3 million, respectively, as of December 31, 2020. The fair value of the convertible notes was influenced by interest rates, the Company’s stock price and stock price volatility, and by prices observed in trading activity for the convertible notes. However, because there have been no trades involving the convertible notes since September 2019, the fair value as of December 31, 2020 uses Level 3 inputs. During 2021, $1.0 million of outstanding convertible 4.5% senior notes converted into 238,777 shares of the Company’s common stock, par value $0.01 per share (common stock), with the remaining $1.1 million of convertible 4.5% senior notes paid in cash upon maturity on July 1, 2021.

Unbilled Receivable

Unbilled receivable primarily represents research funding earned based on actual resources utilized and external expenses incurred under certain of the Company’s collaborator agreements.

Clinical Trial Accruals

Clinical trial expenses are a significant component of research and development expenses, and the Company outsources a significant portion of these activities to third parties. Third-party clinical trial expenses include investigator fees, site costs (patient cost), clinical research organization costs, and costs for central laboratory testing and data management. The accrual for site and patient costs includes inputs such as estimates of patient enrollment, patient cycles

incurred, clinical site activations, and other pass-through costs. These inputs are required to be estimated due to a lag in receiving the actual clinical information from third parties. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred. Clinical trial costs are reflected on the consolidated balance sheets as prepaid assets (to the extent payments exceed costs incurred) or accrued clinical trial costs (to the extent costs incurred exceed payments). These third-party agreements are generally cancelable, and related costs are recorded as research and development expenses as incurred. Non-refundable advance clinical payments for goods or services that will be used or rendered for future R&D activities are recorded as a prepaid asset and recognized as expense as the related goods are delivered or the related services are performed. The Company also records accruals for estimated ongoing clinical research and development costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies, including the phase or completion of events, invoices received, and contracted costs. Significant judgments and estimates may be made in determining the accrued balances at the end of any reporting period. Actual results could differ from the estimates made by the Company. The historical clinical accrual estimates made by the Company have not been materially different from the actual costs.

Leases

The Company determines if an arrangement is a lease at inception. Operating leases include right-of-use (ROU) assets and operating lease liabilities (current and non-current), which are recorded in the Company’s consolidated balance sheets. Single payment capital leases for equipment that are considered finance leases are included in property and equipment in the Company’s consolidated balance sheets. As the single payment obligations have all been made, there is no related liability recorded.

ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. The Company uses the implicit rate when readily determinable. As a number of the Company’s leases do not provide an implicit rate, the Company uses an incremental borrowing rate applicable to the Company based on the information available at the commencement date in determining the present value of lease payments. As the Company has no existing or proposed collateralized borrowing arrangements, to determine a reasonable incremental borrowing rate, the Company considers collateral assumptions, the lease term, the Company’s current credit risk profile, and rates for existing borrowing arrangements for comparable peer companies. The Company accounts for the lease and fixed non-lease components as a single lease component. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for operating lease payments is recognized on a straight-line basis over the lease term.

Other Accrued Liabilities

Other accrued liabilities consisted of the following at December 31, 2021 and 2020 (in thousands):


	December 31,		December 31,
	2021		2020
Accrued contract payments	$	5,558	$	15,576
Accrued clinical trial costs		15,556		11,401
Accrued professional services		839		1,200
Accrued employee benefits		40		39
Accrued public reporting charges		309		319
Other current accrued liabilities		775		785
Total	$	23,077	$	29,320

Accrued contract payments included in the table above primarily relate to external manufacturing, regulatory, and quality-related services. The decrease in the balance as of December 31, 2021 compared to prior year was driven by timing of external manufacturing expenses.

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, (iv) regulatory activities, and (v) external manufacturing operations. 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.

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

Equipment under capital leases is amortized over the lives of the respective leases or the estimated useful lives of the assets, whichever is shorter, and included in depreciation expense.

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 net gains (losses) of $0.7 million and $(1.7) million related to impairment charges and the sale/disposal of certain furniture and equipment during the years ended December 31, 2020, and 2019, respectively. There were no similar gains (losses) recorded during the year ended December 31, 2021.

Impairment of Long-Lived Assets

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 if impairment indicators are present. The Company evaluates the realizability of its long-lived assets based on cash flow expectations for the related asset. Any write-downs to fair value are treated as permanent reductions in the carrying amount of the assets. Accordingly, during the year ended December 31, 2019, the Company recorded a $2.5 million asset impairment charge resulting from restructuring activities, the details of which are further discussed in Note I. Based on this evaluation, except for the impairment recognized during 2019, the Company believes that none of the Company’s remaining long-lived assets were impaired.

Common Stock Warrants

The Company accounts for common stock warrants as either equity-classified or liability-classified instruments based on an assessment of the warrant’s specific terms and applicable authoritative guidance included in Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 480, Distinguishing Liabilities from Equity (“ASC 480”) and ASC 815, Derivatives and Hedging (“ASC 815”). The assessment considers whether the warrants are freestanding financial instruments pursuant to ASC 480, whether the warrants meet the definition of a liability pursuant to ASC 480, and whether the warrants meet all of the requirements for equity classification under ASC 815, including whether the warrants are indexed to the Company’s own common stock and whether the warrant holders could potentially require “net cash settlement” in a circumstance outside of the Company’s control, among other conditions for equity classification. This assessment, which requires the use of professional judgment, is conducted at the time of warrant issuance and as of each subsequent quarterly period end date while the warrants are outstanding.

For issued or modified warrants that meet all of the criteria for equity classification, the warrants are required to be recorded as a component of additional paid-in capital at the time of issuance. For issued or modified warrants that do not meet all the criteria for equity classification, the warrants are required to be recorded at their initial fair value on the date of issuance and remeasured each balance sheet date thereafter. Changes in the estimated fair value of the liability-classified warrants are recognized as a non-cash gain or loss in the accompanying consolidated statements of operations and comprehensive loss.

Computation of Net Loss per Common Share

Basic and diluted net loss per share is calculated based upon the weighted average number of shares of common stock outstanding during the period. Shares of the Company’s common stock underlying pre-funded warrants are included in the calculation of basic and diluted earnings per share. During periods of income, participating securities are allocated a proportional share of income determined by dividing total weighted average participating securities by the sum of the total weighted average common shares and participating securities (the “two-class method”). Shares of the Company’s restricted stock participate in any dividends that may be declared by the Company and are therefore considered to be participating securities. Participating securities have the effect of diluting both basic and diluted earnings per share during periods of income. During periods of loss, no loss is allocated to participating securities since they have no contractual obligation to share in the losses of the Company. Diluted loss per share is computed after giving consideration to the dilutive effect of stock options, convertible notes, and restricted stock that are outstanding during the period, except where such non-participating securities would be anti-dilutive.

The Company’s common stock equivalents, as calculated in accordance with the treasury-stock method for options and unvested restricted stock and the if-converted method for the convertible notes, are shown in the following table (in thousands):



	Year Ended December 31,
	2021	2020	2019
Options outstanding to purchase common stock, shares issuable under the employee stock purchase plan, and unvested restricted stock/units at end of period	21,296	18,459	14,815
Common stock equivalents under treasury stock method for options, shares issuable under the employee stock purchase plan, and unvested restricted stock/units	2,546	1,301	1,020
Shares issuable upon conversion of convertible notes at end of period	—	501	501
Common stock equivalents under if-converted method for convertible notes	—	501	501

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 December 31, 2021, the Company is authorized to grant future awards under three employee share-based compensation plans, which are the ImmunoGen, Inc. 2018 Employee, Director and Consultant Equity Incentive Plan, or the 2018 Plan, the Employee Stock Purchase Plan, or ESPP, and the ImmunoGen Inducement Equity Incentive Plan, or the Inducement Plan. At the annual meeting of shareholders on June 16, 2021, the 2018 Plan was amended to provide for the issuance of stock grants, the grant of options, and the grant of stock-based awards for up to 6,600,000 shares of the Company’s common stock, as well as up to 22,392,986 shares of common stock, which represent the number of shares of common stock remaining under the 2018 Plan as of March 31, 2021, and shares of the Company’s common stock represented by awards granted under the ImmunoGen, Inc. 2016 and 2006 Employee, Director and Consultant Equity Incentive Plans, that may forfeit, expire, or cancel without delivery of shares of common stock or which resulted in the forfeiture of shares of common stock back to the Company on or after March 31, 2021. The Inducement Plan was approved by the Board of Directors in December 2019, and pursuant to subsequent amendments, provided for the issuance of non-qualified option grants for up to 3,500,000 shares of the Company’s common stock as of December 31, 2021. Options awarded under the two plans 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 718, “Compensation—Stock Compensation.” Pursuant to ASC 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. 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 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
	December 31,
	2021	2020	2019
Dividend	None	None	None
Volatility	84.67%	85.07%	76.67%
Risk-free interest rate	0.80%	1.21%	2.20%
Expected life (years)	6.0	6.0	6.0

Using the Black-Scholes option-pricing model, the weighted-average grant date fair values of options granted during the years ended December 31, 2021, 2020, and 2019, were $5.07, $3.28, and $2.81 per share, respectively.

A summary of option activity under the option plans for 2021 is presented below (in thousands, except weighted-average data):


		Weighted-		Weighted-
	Number	Average		Average	Aggregate
	of Stock	Exercise		Remaining	Intrinsic
	Options	Price		Life in Yrs.	Value
Outstanding at December 31, 2020	18,398	$	6.10
Granted	5,324		7.15
Exercised	(872)		3.51
Forfeited/Canceled	(1,631)		8.59
Outstanding at December 31, 2021	21,219	$	6.28	7.34	$	41,425
Exercisable at December 31, 2021	9,619	$	7.10	5.87	$	19,140
Vested and expected to vest at December 31, 2021	21,219	$	6.28	7.34	$	41,425

In 2020, the Company issued 2.6 million performance-based stock options to certain employees, all of which remained outstanding as of December 31, 2021, that will vest upon the achievement of specified performance goals. In October 2021, upon approval by the Compensation Committee of the Company’s Board of Directors, certain terms of the performance-based stock option award agreements were modified. Pursuant to ASC 718, the Company determined the modification to be a Type IV (improbable-to-improbable) modification and revalued the modified awards as of the modification date. Upon assessment of the performance-based stock option awards as of December 31, 2021, the Company determined the first performance goal to be probable of vesting and, as such, recorded $2.6 million of stock-based compensation expense for the year ended December 31, 2021. The fair value of the performance-based options that could be expensed in future periods is $7.8 million.

A summary of restricted stock and restricted stock unit activity under the option plans for 2021 is presented below (in thousands, except weighted-average data):


	Number of	Weighted-
	Restricted	Average Grant
	Stock Shares	Date Fair Value
Unvested at December 31, 2020	61	$	2.47
Granted	75		5.68
Vested	(2)		2.53
Forfeited	(57)		2.47
Unvested at December 31, 2021	77	$	5.59

In June 2018, the Company's Board of Directors, with shareholder approval, adopted the Employee Stock Purchase Plan. Following the automatic share increase on January 1, 2021 under the ESPP’s “evergreen” provision, an aggregate of 2,000,000 shares of common stock have been reserved for issuance under the ESPP. Under the ESPP, eligible participants purchase shares of the Company's common stock at a price equal to 85% of the lesser of the closing price of the Company's common stock on the first business day and the final business day of the applicable plan purchase period. Plan purchase periods are six months and begin on January 1 and July 1 of each year, with purchase dates occurring on the final business day of the given purchase period. The fair value of each ESPP award is estimated on the first day of the offering period using the Black-Scholes option-pricing model. The Company recognizes share-based compensation expense equal to the fair value of the ESPP awards on a straight-line basis over the offering period.

During 2021, 2020, and 2019, approximately 126,000, 122,000, and 356,000 shares, respectively, were issued to participating employees at fair values ranging from $1.20 to $2.29 per share.

Stock compensation expense related to stock options and restricted stock awards granted under the option plans and the ESPP was $16.8 million, $14.0 million, and $13.8 million during the years ended December 31, 2021, 2020, and 2019, respectively. As of December 31, 2021, the estimated fair value of unvested employee awards was $28.6 million. The weighted-average remaining vesting period for these awards is 2.9 years. Also included in stock and deferred stock unit compensation expense in the consolidated statements of cash flows for the years ended December 31, 2021, 2020, and 2019 is $0.7 million, $0.4 million, and $0.3 million, respectively, of expense recorded for directors’ deferred share units, the details of which are discussed in Note H.

A summary of option activity for options vested during the years ended December 31, 2021, 2020, and 2019 is presented below (in thousands):


	Year Ended December 31,
	2021		2020		2019
Total fair value of options vested	$	15,839	$	11,465	$	13,747
Total intrinsic value of options exercised		3,322		746		556
Cash received from the exercise of stock options and ESPP purchases		3,769		1,471		2,873

Comprehensive Loss

The Company presents comprehensive loss in accordance with ASC 220, Comprehensive Income. Comprehensive loss is comprised of the Company’s net loss for all periods presented.

Segment Information

During all periods presented, the Company continued to operate in one reportable business segment under the management approach of ASC 280, Segment Reporting, which is the business of the discovery and development of ADCs for the treatment of cancer.

The percentages of revenues recognized from significant customers of the Company in the years ended December 31, 2021, 2020, and 2019 are included in the following table:


	Year Ended December 31,
Collaborative Partner:	2021	2020	2019
Roche	67%	53%	64%
Huadong	24%	-%	-%
Jazz	-%	46%	18%
CytomX	-%	-%	13%

There were no other customers of the Company with significant revenues in the periods presented.

Recently Adopted Accounting Pronouncements

In December 2019, the FASB issued Accounting Standards Update (“ASU”) 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, which is intended to simplify the accounting for income taxes. ASU 2019-12 removes certain exceptions to the general principles in ASC 740 and also clarifies and amends existing guidance to improve consistent application. The Company adopted the standard on January 1, 2021, and it did not have a material effect on the Company’s consolidated financial statements.

In November 2018, the FASB issued ASU No. 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606, which clarifies that certain transactions between participants in a collaborative arrangement should be accounted for under ASC 606 when the counterparty is a customer. In addition, ASU 2018-18 adds unit-of-account guidance to ASC 808 in order to align this guidance with ASC 606 and also precludes an entity from presenting consideration from a transaction in a collaborative arrangement as revenue from contracts with customers if the counterparty is not a customer for that transaction. This guidance is effective for annual reporting periods beginning after December 15, 2019, including interim periods within those annual reporting periods. The Company adopted the standard on January 1, 2020, and it did not have a material effect on the Company’s consolidated financial statements.

In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments, to require financial assets carried at amortized cost to be presented at the net amount expected to be collected based on

historical experience, current conditions, and forecasts. The ASU is effective for interim and annual periods beginning after December 15, 2019. Adoption of the ASU is on a modified retrospective basis. The Company adopted the standard on January 1, 2020, and it did not have a material effect on the Company’s consolidated financial statements.

No other recently issued or effective ASUs had, or are expected to have, a material effect on the Company's results of operations, financial condition, or liquidity.