Agreements	9 Months Ended
Sep. 30, 2019
Agreements
Agreements	C.Agreements Significant Collaborative Agreements Roche In May 2000, the Company granted Genentech, now a member of the Roche Group, an exclusive license to use the Company’s maytansinoid ADC technology. Pursuant to this agreement, Roche developed and received marketing approval for its HER2-targeting ADC compound, Kadcyla, in the U.S., Europe, Japan, and numerous other countries. 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, $32.1 million and $22.9 million of non-cash royalties on net sales of Kadcyla were recorded and included in non-cash royalty revenue for the nine months ended September 30, 2019 and 2018. Kadcyla sales occurring after January 1, 2015 were covered by a royalty purchase agreement whereby the associated cash, except for a residual tail, was remitted to Immunity Royalty Holdings, L.P, or IRH. In January 2019, the Company sold its residual tail to OMERS, the defined benefit pension plan for municipal employees in the Province of Ontario, Canada, for a net payment of $65.2 million, as discussed further in Note E. Simultaneously, OMERS purchased IRH’s right to the royalties the Company previously sold as described above, therefore obtaining the rights to 100% of the royalties received from that date on. On May 3, 2019, Roche notified the Company that the U.S. Food and Drug Administration approved Kadcyla for adjuvant (after surgery) treatment of people with HER2-positive early breast cancer who have residual invasive disease after neoadjuvant (before surgery) taxane and Herceptin® (trastuzumab)-based treatment, resulting in a $5 million regulatory milestone payment to the Company for a first extended indication, which is included in license and milestone fees for the nine months ended September 30, 2019. The next potential milestone the Company will be entitled to receive will be a $5 million regulatory milestone for marketing approval of Kadcyla for a second extended indication as defined in the license. Novartis The Company granted Novartis exclusive development and commercialization licenses to the Company’s maytansinoid and IGN ADC technology for use with antibodies to six specified targets under a now-expired right-to-test agreement established in 2010. The Company received a $45 million upfront payment in connection with the execution of the right-to-test agreement in 2010, and for each development and commercialization license taken for a specific target, the Company received an exercise fee of $1 million and is entitled to receive up to a total of $199.5 million in milestone payments, plus royalties on the commercial sales of any resulting products. In May 2018, Novartis terminated one of its six development and commercialization licenses. As a result, the Company recorded the remaining $978,000 balance of the upfront payment that had been allocated to future performance obligations under this license as revenue, which is included in license and milestone fees for the nine months ended September 30, 2018. Takeda In March 2015, the Company entered into a three-year right-to-test agreement with Takeda through its wholly owned subsidiary, Millennium Pharmaceuticals, Inc. The agreement provided Takeda with the right to (a) take exclusive options, with certain restrictions, to individual targets selected by Takeda for specified option periods, (b) test the Company’s ADC technology with Takeda’s antibodies directed to the targets optioned under a right-to-test, or research, license, and (c) take exclusive licenses to use the Company’s ADC technology to develop and commercialize products to targets optioned for up to two individual targets on terms specified in the right-to-test agreement. The first license was granted to Takeda in December 2015. In March 2018, the right-to-test agreement expired without Takeda exercising its option to a second license or extending or expanding the agreement as it had the right to do for a third license. Accordingly, the remaining $10.9 million of revenue that had been deferred for such performance obligations was recognized as revenue and is included in license and milestone fees for the nine months ended September 30, 2018. In May 2018, Takeda enrolled its first patient in a Phase I clinical trial, triggering a $5 million milestone payment to the Company. Due to the likelihood of this milestone being attained, this milestone was recognized as a contract asset as part of the cumulative adjustment to transition to ASC 606. It had been previously allocated to the delivered license and the right to technological improvements. The next potential milestone payment the Company will be entitled to receive will be a $10 million development milestone payment with the initiation of a Phase II clinical trial. Takeda is responsible for the manufacturing, product development, and marketing of any products resulting from the remaining license. Fusion In December 2016, the Company entered into an exclusive license agreement to a specified target with Fusion Pharmaceuticals Inc. The Company is entitled to receive up to a total of $50 million in milestone payments, plus royalties on the commercial sales of any resulting products. The total milestones are categorized as follows: development milestones—$15 million; and sales milestones—$35 million. During the three months ended September 30, 2018, a development milestone related to dosing of a first patient in a Phase I clinical trial became probable of being attained, and accordingly, $500,000 was recorded as license and milestone fee revenue in the three and nine months ended September 30, 2018, which was subsequently paid in 2019. The next potential milestone payment the Company will be entitled to receive will be a $1.5 million development milestone payment with the initiation of a Phase II clinical trial. Fusion is responsible for the manufacturing, product development, and marketing of any products resulting from the license. Debiopharm In May 2017, Debiopharm acquired the Company’s IMGN529 program, a clinical-stage anti-CD37 ADC for the treatment of patients with B-cell malignancies. Under the terms of the Exclusive License and Asset Purchase agreement, the Company received a $25 million upfront payment for specified assets related to IMGN529 and a paid-up license to the Company’s ADC technology. Upon substantial completion of the transfer of the Company’s technologies related to the program (technology transfer) in the fourth quarter of 2017, the Company achieved a $5 million milestone, $4.5 million of which was received in December 2017 and the balance in January 2018 upon delivery of the final materials related to the transfer. Accordingly, $500,000 was recorded as license and milestone fee revenue in the nine months ended September 30, 2018. In addition, the Company is eligible for a second success-based milestone payment of $25 million upon IMGN529 entering a Phase 3 clinical trial. The milestone payment will be significantly reduced if Debiopharm commences an anti-CD37 ADC Phase 3 trial using the Company’s ADC technology but not ImmunoGen’s proprietary anti-CD37 antibody prior to IMGN529 entering a Phase 3 trial. The Company does not believe this scenario is likely to occur. For additional information related to these agreements, as well as the Company’s other significant collaborative agreements, please read Note C, Agreements, to the consolidated financial statements included within the Company’s 2018 Annual Report on Form 10-K.

Agreements

9 Months Ended

Sep. 30, 2019

C.Agreements

Significant Collaborative Agreements

Roche

In May 2000, the Company granted Genentech, now a member of the Roche Group, an exclusive license to use the Company’s maytansinoid ADC technology. Pursuant to this agreement, Roche developed and received marketing approval for its HER2-targeting ADC compound, Kadcyla, in the U.S., Europe, Japan, and numerous other countries. 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, $32.1 million and $22.9 million of non-cash royalties on net sales of Kadcyla were recorded and included in non-cash royalty revenue for the nine months ended September 30, 2019 and 2018. Kadcyla sales occurring after January 1, 2015 were covered by a royalty purchase agreement whereby the associated cash, except for a residual tail, was remitted to Immunity Royalty Holdings, L.P, or IRH. In January 2019, the Company sold its residual tail to OMERS, the defined benefit pension plan for municipal employees in the Province of Ontario, Canada, for a net payment of $65.2 million, as discussed further in Note E. Simultaneously, OMERS purchased IRH’s right to the royalties the Company previously sold as described above, therefore obtaining the rights to 100% of the royalties received from that date on.

On May 3, 2019, Roche notified the Company that the U.S. Food and Drug Administration approved Kadcyla for adjuvant (after surgery) treatment of people with HER2-positive early breast cancer who have residual invasive disease after neoadjuvant (before surgery) taxane and Herceptin® (trastuzumab)-based treatment, resulting in a $5 million regulatory milestone payment to the Company for a first extended indication, which is included in license and milestone fees for the nine months ended September 30, 2019. The next potential milestone the Company will be entitled to receive will be a $5 million regulatory milestone for marketing approval of Kadcyla for a second extended indication as defined in the license.

Novartis

The Company granted Novartis exclusive development and commercialization licenses to the Company’s maytansinoid and IGN ADC technology for use with antibodies to six specified targets under a now-expired right-to-test agreement established in 2010. The Company received a $45 million upfront payment in connection with the execution of the right-to-test agreement in 2010, and for each development and commercialization license taken for a specific target, the Company received an exercise fee of $1 million and is entitled to receive up to a total of $199.5 million in milestone payments, plus royalties on the commercial sales of any resulting products. In May 2018, Novartis terminated one of its six development and commercialization licenses. As a result, the Company recorded the remaining $978,000 balance of the upfront payment that had been allocated to future performance obligations under this license as revenue, which is included in license and milestone fees for the nine months ended September 30, 2018.

Takeda

In March 2015, the Company entered into a three-year right-to-test agreement with Takeda through its wholly owned subsidiary, Millennium Pharmaceuticals, Inc. The agreement provided Takeda with the right to (a) take exclusive options, with certain restrictions, to individual targets selected by Takeda for specified option periods, (b) test the Company’s ADC technology with Takeda’s antibodies directed to the targets optioned under a right-to-test, or research, license, and (c) take exclusive licenses to use the Company’s ADC technology to develop and commercialize products to targets optioned for up to two individual targets on terms specified in the right-to-test agreement. The first license was granted to Takeda in December 2015. In March 2018, the right-to-test agreement expired without Takeda exercising its option to a second license or extending or expanding the agreement as it had the right to do for a third license. Accordingly, the remaining $10.9 million of revenue that had been deferred for such performance obligations was recognized as revenue and is included in license and milestone fees for the nine months ended September 30, 2018. In May 2018, Takeda enrolled its first patient in a Phase I clinical trial, triggering a $5 million milestone payment to the Company. Due to the likelihood of this milestone being attained, this milestone was recognized as a contract asset as part of the cumulative adjustment to transition to ASC 606. It had been previously allocated to the delivered license and the right to technological improvements. The next potential milestone payment the Company will be entitled to receive will

be a $10 million development milestone payment with the initiation of a Phase II clinical trial. Takeda is responsible for the manufacturing, product development, and marketing of any products resulting from the remaining license.

Fusion

In December 2016, the Company entered into an exclusive license agreement to a specified target with Fusion Pharmaceuticals Inc. The Company is entitled to receive up to a total of $50 million in milestone payments, plus royalties on the commercial sales of any resulting products. The total milestones are categorized as follows: development milestones—$15 million; and sales milestones—$35 million. During the three months ended September 30, 2018, a development milestone related to dosing of a first patient in a Phase I clinical trial became probable of being attained, and accordingly, $500,000 was recorded as license and milestone fee revenue in the three and nine months ended September 30, 2018, which was subsequently paid in 2019. The next potential milestone payment the Company will be entitled to receive will be a $1.5 million development milestone payment with the initiation of a Phase II clinical trial. Fusion is responsible for the manufacturing, product development, and marketing of any products resulting from the license.

Debiopharm

In May 2017, Debiopharm acquired the Company’s IMGN529 program, a clinical-stage anti-CD37 ADC for the treatment of patients with B-cell malignancies. Under the terms of the Exclusive License and Asset Purchase agreement, the Company received a $25 million upfront payment for specified assets related to IMGN529 and a paid-up license to the Company’s ADC technology. Upon substantial completion of the transfer of the Company’s technologies related to the program (technology transfer) in the fourth quarter of 2017, the Company achieved a $5 million milestone, $4.5 million of which was received in December 2017 and the balance in January 2018 upon delivery of the final materials related to the transfer. Accordingly, $500,000 was recorded as license and milestone fee revenue in the nine months ended September 30, 2018. In addition, the Company is eligible for a second success-based milestone payment of $25 million upon IMGN529 entering a Phase 3 clinical trial. The milestone payment will be significantly reduced if Debiopharm commences an anti-CD37 ADC Phase 3 trial using the Company’s ADC technology but not ImmunoGen’s proprietary anti-CD37 antibody prior to IMGN529 entering a Phase 3 trial. The Company does not believe this scenario is likely to occur.

For additional information related to these agreements, as well as the Company’s other significant collaborative agreements, please read Note C, Agreements, to the consolidated financial statements included within the Company’s 2018 Annual Report on Form 10-K.