Agreements	12 Months Ended
Dec. 31, 2019
Agreements
Agreements	C.Agreements Significant Collaborative Agreements Roche In 2000, the Company granted Genentech, now a unit of Roche, an exclusive development and commercialization license to use the Company’s maytansinoid ADC technology with antibodies, such as trastuzumab, or other proteins that target HER2. Under the terms of this agreement, Roche has exclusive worldwide rights to develop and commercialize maytansinoid ADC compounds targeting HER2. In 2013, the HER2-targeting ADC, Kadcyla, was approved for marketing in the U.S., Japan, and the European Union, or EU. Roche has also received marketing approval in various other countries around the world. Roche is responsible for the manufacturing, product development, and marketing of any products resulting from 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 December 31, 2019, the Company has received and recognized $13.5 million and $25.5 million in development and regulatory milestone payments, respectively, related to Kadcyla. On May 3, 2019, Roche notified the Company that the FDA 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 year ended December 31, 2019. The next and final 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 agreement. 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, $47.4, $32.2, and $28.1 million of non-cash royalties on net sales of Kadcyla were recorded and included in royalty revenue for the years ended December 31, 2019, 2018 and 2017. Kadcyla sales occurring after January 1, 2015 are covered by a royalty purchase agreement whereby the associated cash, except for a residual tail, would have been remitted to Immunity Royalty Holdings, L.P, or IRH. In January 2019, the Company announced the sale of its residual tail to OMERS, the defined benefit pension plan for municipal employees in the Province of Ontario, Canada, for $65.2 million, net of fees, as discussed further in Note F. Simultaneously, OMERS purchased IRH’s right to the royalties the Company previously sold as described above, thereby obtaining the rights to 100% of the royalties received from that date on. Roche, through its Genentech unit, also has licenses for the exclusive right to use the Company’s maytansinoid ADC technology with antibodies to four undisclosed targets, which were granted under the terms of a separate, now expired, 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 December 31, 2019. 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. Amgen/Oxford BioTherapeutics Under a now-expired right-to-test agreement established in 2000, the Company granted Amgen four exclusive development and commercialization licenses, for which the Company received an exercise fee of $1 million for each license taken. Three of the four licenses have since been terminated by Amgen, and Amgen has sublicensed its rights under the one remaining license to Oxford BioTherapeutics Ltd. (OBT). For the remaining development and commercialization license, the Company is entitled to receive up to a total of $34 million in milestone payments, plus royalties on the commercial sales of any resulting products. The total milestones are categorized as follows: development milestones—$9 million; regulatory milestones—$20 million; and sales milestones—$5 million. Amgen (or its sublicensee(s)) is responsible for the manufacturing, development, and marketing of any products resulting from this development and commercialization license. Through December 31, 2019, the Company has received and recognized an aggregate of $4 million in milestone payments for compounds covered under this agreement now or in the past. The next potential milestone the Company will be entitled to receive under the remaining license will be a development milestone for the first dosing of a patient in a U.S. Phase II clinical trial, which will result in a $3 million payment being due. Sanofi In 2003, the Company entered into a broad collaboration agreement with Sanofi (formerly Aventis Pharmaceuticals) to discover, develop, and commercialize antibody-based products. The collaboration agreement provided 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 ADC technology in the creation of products developed to these targets. Through December 31, 2019, the Company recognized an aggregate of $26.5 million in development milestone payments for compounds covered under this agreement in the past, including $6 million of milestone payments received and included in license and milestone fee revenue for the year ended December 31, 2017. In May 2017, the Company and an affiliate of Sanofi amended the license agreements covering all compounds in development by Sanofi using the Company’s technology. Under the terms of the amended 2003 collaboration and license agreement, the Company granted Sanofi a fully-paid, exclusive license to develop, manufacture, and commercialize four experimental compounds in development. The Company also amended a separate 2013 exclusive license entered into pursuant to a separate, now-expired right-to-test agreement to grant Sanofi a fully-paid, exclusive license to develop, manufacture, and commercialize another experimental compound being studied for the treatment of solid tumors. As consideration for these amendments, the Company received a $30 million payment and agreed to forego a limited co-promotion option in the U.S. with respect to the compounds covered by the 2003 agreement, as well as future milestones or royalties with respect to all licensed products. In accordance with ASC-605-25, the Company determined that there were no remaining deliverables upon execution of the amendments, and accordingly, the $30 million was recognized as revenue and is included in license and milestone fee revenue for the year ended December 31, 2017. Biotest In 2006, the Company granted Biotest an exclusive development and commercialization license to our maytansinoid ADC technology for use with antibodies that target CD138. The product candidate indatuximab ravtansine is in development under this agreement. Biotest is responsible for the manufacturing, 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. In September 2008, Biotest began Phase 1 evaluation of indatuximab ravtansine which triggered a $500,000 milestone payment to the Company. The next potential milestone the Company will be entitled to receive will be a development milestone for commencement of a Phase 2b clinical trial (as defined in the agreement) which will result in a $2 million payment being due. Bayer In 2008, the Company granted Bayer an exclusive development and commercialization license to the Company’s maytansinoid ADC 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 which was recognized as revenue ratably over the Company’s estimated period of substantial involvement which concluded in September 2012. For each compound developed and marketed by Bayer under this collaboration the Company is entitled to receive a total of $170.5 million in milestone payments, plus tiered royalties between 4 - 7% 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 December 31, 2019, the Company has received and recognized an aggregate of $13 million in milestone payments under this agreement. In July 2017, Bayer announced that its Phase 2 clinical study did not meet its primary endpoint of progression-free survival. The safety and tolerability of anetumab ravtansine were consistent with earlier clinical findings and Bayer is continuing development in additional studies, including a Phase 1b multi-indication study in six different types of advanced solid tumors, and a Phase 1b combination-study in patients with recurrent platinum-resistant ovarian cancer. The next potential milestone the Company will be entitled to receive will be either a development milestone for commencement of a pivotal clinical trial for a second indication for anetumab ravtansine which will result in a $2 million payment being due or a regulatory milestone for filing of regulatory approval for its first indication for anetumab ravtansine which will result in a $6 million payment being due. 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. The total milestones are categorized as follows: development milestones—$22.5 million; regulatory milestones—$77 million; and sales milestones—$100 million. The initial three-year term of the right-to-test agreement was extended by Novartis in October 2013 for an additional one-year period by payment of a $5 million fee to the Company. The Company also is entitled to receive payments for research and development activities performed on behalf of Novartis. Novartis is responsible for the manufacturing, development, and marketing of any products resulting from this agreement. In March 2013, the Company and Novartis amended the right-to-test agreement so that Novartis could take a license to develop and commercialize products directed at two undisclosed, related 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 no longer be converted to an exclusive target due to the expiration of the right-to-test agreement. The Company received a $3.5 million fee in connection with the execution of the amendment to the agreement. In connection with the amendment, in March 2013, the Company granted Novartis 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 received a $1 million upfront fee with the execution of this license. In May 2018, Novartis terminated the license. 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 year ended December 31, 2018. In October 2013 and November 2013, the Company granted Novartis its second and third exclusive licenses to single targets, and in October 2014, the three remaining exclusive licenses, each triggering a $1 million upfront payment to the Company and the opportunity to receive milestone payments totaling $199.5 million, as outlined above, plus royalties on the commercial sales of any resulting products. In January 2015 and May 2015, Novartis initiated Phase 1, first-in-human clinical testing of its cKit-targeting ADC product candidate, LOP628, and P-cadherin-targeting ADC product candidate, PCA062, respectively, triggering a $5 million development milestone payment to the Company with each event. In December 2016, Novartis initiated Phase 1, first-in-human clinical testing of its CDH6-targeting ADC product candidate, HKT288, triggering a $5 million milestone payment which the Company received in 2017. Novartis later discontinued clinical testing of these three products. In December 2019, a development milestone related to dosing a first patient in a Phase 1 clinical trial for a separate licensed product became probable of being attained. Accordingly, $4.7 million of the $5.0 million milestone that was allocated to the delivered license was recorded as revenue and is included in license and milestone fees for the year ended December 31, 2019, and $0.3 million that was allocated to future technological improvements was deferred and will be recognized as revenue ratably over the estimated term of the license. The next potential payment the Company could receive would be either a $7.5 million development milestone for commencement of a Phase 2 clinical trial or a $5 million development milestone for commencement of a Phase 1 clinical trial. Lilly The Company granted Eli Lilly and Company (Lilly) three exclusive development and commercialization licenses under a now-expired right-to-test agreement established in 2011. The Company received a $20 million upfront payment in connection with the execution of the right-to-test agreement in 2011. Under the terms of this right-to-test agreement, the first license had no associated exercise fee, and the second and third licenses each had a $2 million exercise fee. The first development and commercialization license was granted in August 2013 and the agreement was amended in December 2013 to provide Lilly with an extension provision and retrospectively include a $2 million exercise fee for the first license in lieu of the fee due for either the second or third license. The second and third licenses were granted in December 2014, with one including the $2 million exercise fee and the other not. In October 2018, Lilly terminated its three development and commercialization licenses. As a result, the Company recorded the remaining $692,000 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 year ended December 31, 2018. CytomX In 2016, the Company granted CytomX an exclusive development and commercialization license to the Company’s maytansinoid ADC technology for use with Probodies™ that target CD166 under a now expired reciprocal right-to-test agreement. The Company neither received nor made an upfront cash payment in connection with the execution of the right-to-test agreement or the license agreement. An amendment of the agreement executed simultaneously with the license, granted CytomX the right, for a specified period of time, to substitute the specified target with another as yet unspecified target. Accordingly, the revenue associated with this license was deferred until the expiration of that substitution right in January 2017, whereupon the Company recognized $12.7 million of the $13 million of arrangement consideration allocated to the development and commercialization license, which is included in license and milestone fee revenue for the year ended December 31, 2017. With respect to the development and commercialization license granted to CytomX, the Company is entitled to receive up to a total of $160 million in milestone payments plus royalties on the commercial sales of any resulting product. The total milestones are categorized as follows: development milestones—$10 million; regulatory milestones—$50 million; and sales milestones—$100 million. In June 2017, CytomX enrolled its first patient in a Phase 1 clinical trial for its product candidate, CX-2009, triggering a $1 million development milestone payment which is included in license and milestone fee revenue for the year ended December 31, 2017. In December 2019, a development milestone related to dosing of a first patient in a Phase 2 clinical trial became probable of being attained, which resulted in $3.0 million of license and milestone fee revenue being recorded in 2019. On February 21, 2020, CytomX notified the Company that it had enrolled its first patient in the aforementioned Phase 2 clinical trial. The next payment the Company could receive would be a $6 million development milestone payment with commencement of a Phase III clinical trial. CytomX is responsible for the manufacturing, development, and marketing of any products resulting from the development and commercialization license taken by CytomX under this collaboration. Costs directly attributable to the CytomX collaborative agreement are comprised of compensation and benefits related to employees who provided research and development services on behalf of CytomX as well as costs of clinical materials sold. Indirect costs are not identified to individual collaborators. The costs related to the research and development services amounted to $195,000 and $256,000 for the years ended December 31, 2018 and 2017, respectively. The costs related to clinical materials sold were $3.5 million and $1.0 million for the years ended December 31, 2018 and 2017, respectively. There were no similar costs recorded subsequently. In 2017, we took exclusive development and commercialization licenses to CytomX’s proprietary antibody-masking (Probody) technology for use with Probodies that target two specified targets under the same reciprocal right-to-test agreement. The Company terminated one of these licenses for convenience prior to the end of 2017, and terminated the second license in December 2019 in connection with the grant of the EpCAM license to CytomX discussed further below. No upfront cash payments were made by the Company with the execution of these license agreements. The arrangement was accounted for based on the fair value of the items exchanged. The items to be delivered to CytomX under the arrangement are accounted for under the Company’s revenue recognition policy. The items that were received from CytomX were recorded as research and development expenses as incurred. In December 2019, the Company granted CytomX an exclusive development and commercialization license to maytansinoid and IGN ADC technology for use with Probodies™ that target EpCAM. Pursuant to the license agreement, in January 2020, the Company received a $7.5 million upfront payment, of which $7.3 million was recorded as license and milestone fee revenue upon delivery of the license to CytomX in December 2019 and $200,000 was deferred until delivery of certain materials as these performance obligations were determined to be distinct. The Company is also entitled to receive up to a total of $355 million in milestone payments plus royalties on the commercial sales of any resulting product. The total milestones are categorized as follows: development milestones—$35 million; regulatory milestones—$170 million; and sales milestones—$150 million. CytomX is responsible for the manufacturing, product development, and marketing of any products resulting from this license. Takeda In March 2015, the Company entered into a three-year right-to-test agreement with Takeda Pharmaceutical Company Limited (Takeda) through its wholly owned subsidiary, Millennium Pharmaceuticals, Inc. The agreement provides 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 by the end of the term of the right-to-test agreement, after which any then outstanding options would lapse. Takeda had the right to extend the three-year right-to-test period for one additional year by payment to the Company of $4 million. Alternatively, Takeda had the right to expand the scope of the right-to-test agreement by payment to the Company of $8 million. Takeda is responsible for the manufacturing, development, and marketing of any products resulting from this collaboration. The Company received a $20 million upfront payment in connection with the execution of the right-to-test agreement and, for each development and commercialization license taken, is entitled to receive up to a total of $210 million in milestone payments, plus royalties on the commercial sales of any resulting products. The total milestones are categorized as follows: development milestones—$30 million; regulatory milestones—$85 million; and sales milestones—$95 million. The Company also is entitled to receive payments for delivery of cytotoxic agents to Takeda and research and development activities performed on behalf of Takeda. A first license was granted to Takeda in December 2015, whereupon the Company recognized $8.6 million of the arrangement consideration allocated to the development and commercialization licenses. In March 2018, the right-to-test agreement expired without Takeda exercising its option to a second license or extending the agreement 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 year ended December 31, 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 2 clinical trial. Costs directly attributable to the Takeda collaborative agreement are comprised of compensation and benefits related to employees who provided research and development services on behalf of Takeda. Indirect costs are not identified to individual collaborators. The costs related to the research and development services amounted to $199,000 and $913,000, for the years ended December 31, 2018 and 2017, respectively. The costs related to clinical materials sold were $650,000 and $2.1 million for the years ended December 31, 2018 and 2017, respectively. There were no similar costs recorded subsequently. 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 year ended December 31, 2018, a development milestone related to dosing of a first patient in a Phase I clinical trial became probable of being attained, which resulted in a $500,000 contract asset and the related license and milestone fee revenue being recorded in that year. It 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, development, and marketing of any products resulting from the license. Debiopharm In May 2017, Debiopharm International SA (Debiopharm) acquired the Company’s IMGN529 program, a clinical-stage anti-CD37 ADC for the treatment of patients with B-cell malignancies, such as non-Hodgkin lymphomas (NHL). 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 and a $5 million milestone payment upon substantial completion of the transfer of ImmunoGen technologies related to the program (technology transfer), which was completed in the fourth quarter of 2017. $4.5 million was received for this milestone in December 2017, and the balance in January 2018 upon delivery of the final materials related to the transfer. Accordingly, the Company recorded $500,000 and $29.5 million of license and milestone fee revenue in 2018 and 2017, respectively. In addition, ImmunoGen 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 a Phase 3 trial using the Company’s technology but not the IMGN529 antibody commences prior to IMGN529 entering a Phase 3 trial. The Company does not believe this scenario is likely to occur. Jazz Pharmaceuticals In August 2017, the Company entered into a Collaboration and Option Agreement (the “Option Agreement”) with Jazz Pharmaceuticals Ireland Limited (Jazz), a subsidiary of Jazz Pharmaceuticals plc, granting Jazz exclusive, worldwide rights to opt into development and commercialization of two early-stage, hematology-related ADC programs, as well as an additional program to be designated during the term of the agreement. The programs covered under the agreement included IMGN779, a CD33-targeted ADC for the treatment of acute myeloid leukemia (AML) then in Phase 1 testing, IMGN632, a CD123-targeted ADC for hematological malignancies also then in Phase 1 testing, and an early-stage program to be determined at a later date. In October 2019, Jazz exercised certain of its opt-out rights under the Option Agreement following the termination of the Company’s IMGN779 development program. In addition, in November 2019, the Company executed a First Amendment (the “First Amendment”) to the Option Agreement. The First Amendment included an exercise of their opt-out rights related to the termination of the Company’s early research programs covered by the Option Agreement in connection with the Company’s previously announced restructuring. Under the terms of the Option Agreement, the exercise of both of these opt-out rights will result in a pro-rata reduction in Jazz’s obligation to provide development funding, which will now be limited to support of the Company’s IMGN632 development program. The First Amendment also provides for a streamlining of the governance structure under the Option Agreement and a reduction in the option exercise fee that Jazz would pay for the remaining product under the Option Agreement or a back-up to that product. As part of the Option agreement, Jazz made an upfront payment of $75 million to the Company. Additionally, Jazz had also agreed to pay the Company up to $100 million in development funding over seven years to support the three ADC programs. That obligation has now been reduced for years 2020 through 2024 pursuant to the terms of the First Amendment. Jazz may exercise its option with respect to IMGN632 at any time prior to a pivotal study or at any time prior to the filing of a biologics license application (BLA) upon payment of an option exercise fee of mid-double digit millions or low triple digit millions, respectively. Following any opt-in, Jazz would be generally responsible for any further development as well as for potential regulatory submissions and commercialization and Jazz and the Company would share costs associated with developing and obtaining regulatory approvals of the applicable product in the U.S. and EU. If Jazz elects to opt-in to IMGN632, the Company would be eligible to receive milestone payments based on receiving regulatory approvals aggregating $100 million plus tiered royalties as a percentage of commercial sales by Jazz, which will vary depending upon sales levels and the stage of development at the time of opt-in. The Company has the right to co-commercialize IMGN632 in the U.S. with profit sharing in lieu of Jazz's payment of the U.S. milestone and royalties to the Company. Due to the involvement the Company and Jazz both had in the development and commercialization of the products, as well as both parties being part of the cost share agreement and exposed to significant risks and rewards dependent on the commercial success of the products, the arrangement was determined to be a collaborative arrangement within the scope of ASC 808. Accordingly, the Company carved out the research and development activities and the related cost sharing arrangement with Jazz. Payments for such activities are recorded as research and development expense and reimbursements received from Jazz are recognized as an offset to research and development expense in the accompanying statement of operations during the development period. Included in research and development expense for the years ended December 31, 2019, 2018 and 2017, are $12.5, $10.0 and $3.3 million of credits related to reimbursements from Jazz, respectively. The non-refundable, upfront arrangement consideration of $75 million was allocated to the three License Options. The amount allocated to the rights to future technological improvements under the relative selling price method was deemed immaterial and, therefore, not segregated from the License Options. In conjunction with the opt-out of IMGN779, the Company recognized $14.5 million of the deferred revenue in the year ended December 31, 2019. In connection with the execution of the First Amendment, the amount of the transaction price originally allocated to the early research product Options was reallocated to the to the IMGN632 Option, which represents the only remaining material right. The amount allocated to the IMGN632 option will be recognized as revenue when exercised by Jazz or upon expiration. The Company does not control when Jazz will exercise its option for its development and commercialization license. As a result, the Company cannot predict when it will recognize revenue related to the delivery of the license and, accordingly, the remaining upfront payment of $60.5 million is included in long-term deferred revenue as of December 31, 2019.

Agreements

12 Months Ended

Dec. 31, 2019

C.Agreements

Significant Collaborative Agreements

Roche

In 2000, the Company granted Genentech, now a unit of Roche, an exclusive development and commercialization license to use the Company’s maytansinoid ADC technology with antibodies, such as trastuzumab, or other proteins that target HER2. Under the terms of this agreement, Roche has exclusive worldwide rights to develop and commercialize maytansinoid ADC compounds targeting HER2. In 2013, the HER2-targeting ADC, Kadcyla, was approved for marketing in the U.S., Japan, and the European Union, or EU. Roche has also received marketing approval in various other countries around the world. Roche is responsible for the manufacturing, product development, and marketing of any products resulting from 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 December 31, 2019, the Company has received and recognized $13.5 million and $25.5 million in development and regulatory milestone payments, respectively, related to Kadcyla. On May 3, 2019, Roche notified the Company that the FDA 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 year ended December 31, 2019. The next and final 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 agreement.

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, $47.4, $32.2, and $28.1 million of non-cash royalties on net sales of Kadcyla were recorded and included in royalty revenue for the years ended December 31, 2019, 2018 and 2017. Kadcyla sales occurring after January 1, 2015 are covered by a royalty purchase agreement whereby the associated cash, except for a residual tail, would have been remitted to Immunity Royalty Holdings, L.P, or IRH. In January 2019, the Company announced the sale of its residual tail to OMERS, the defined benefit pension plan for municipal employees in the Province of Ontario, Canada, for $65.2 million, net of fees, as discussed further in Note F. Simultaneously, OMERS purchased IRH’s right to the royalties the Company previously sold as described above, thereby obtaining the rights to 100% of the royalties received from that date on.

Roche, through its Genentech unit, also has licenses for the exclusive right to use the Company’s maytansinoid ADC technology with antibodies to four undisclosed targets, which were granted under the terms of a separate, now expired, 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 December 31, 2019. 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.

Amgen/Oxford BioTherapeutics

Under a now-expired right-to-test agreement established in 2000, the Company granted Amgen four exclusive development and commercialization licenses, for which the Company received an exercise fee of $1 million for each license taken. Three of the four licenses have since been terminated by Amgen, and Amgen has sublicensed its rights under the one remaining license to Oxford BioTherapeutics Ltd. (OBT).

For the remaining development and commercialization license, the Company is entitled to receive up to a total of $34 million in milestone payments, plus royalties on the commercial sales of any resulting products. The total milestones are categorized as follows: development milestones—$9 million; regulatory milestones—$20 million; and sales milestones—$5 million. Amgen (or its sublicensee(s)) is responsible for the manufacturing, development, and marketing of any products resulting from this development and commercialization license. Through December 31, 2019, the Company has received and recognized an aggregate of $4 million in milestone payments for compounds covered under this agreement now or in the past. The next potential milestone the Company will be entitled to receive under the remaining license will be a development milestone for the first dosing of a patient in a U.S. Phase II clinical trial, which will result in a $3 million payment being due.

Sanofi

In 2003, the Company entered into a broad collaboration agreement with Sanofi (formerly Aventis Pharmaceuticals) to discover, develop, and commercialize antibody-based products. The collaboration agreement provided 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 ADC technology in the creation of products developed to these targets. Through December 31, 2019, the Company recognized an aggregate of $26.5 million in development milestone payments for compounds covered under this agreement in the past, including $6 million of milestone payments received and included in license and milestone fee revenue for the year ended December 31, 2017.

In May 2017, the Company and an affiliate of Sanofi amended the license agreements covering all compounds in development by Sanofi using the Company’s technology. Under the terms of the amended 2003 collaboration and license agreement, the Company granted Sanofi a fully-paid, exclusive license to develop, manufacture, and commercialize four experimental compounds in development. The Company also amended a separate 2013 exclusive license entered into pursuant to a separate, now-expired right-to-test agreement to grant Sanofi a fully-paid, exclusive license to develop, manufacture, and commercialize another experimental compound being studied for the treatment of solid tumors. As consideration for these amendments, the Company received a $30 million payment and agreed to forego a limited co-promotion option in the U.S. with respect to the compounds covered by the 2003 agreement, as well as future milestones or royalties with respect to all licensed products.

In accordance with ASC-605-25, the Company determined that there were no remaining deliverables upon execution of the amendments, and accordingly, the $30 million was recognized as revenue and is included in license and milestone fee revenue for the year ended December 31, 2017.

Biotest

In 2006, the Company granted Biotest an exclusive development and commercialization license to our maytansinoid ADC technology for use with antibodies that target CD138. The product candidate indatuximab ravtansine is in development under this agreement. Biotest is responsible for the manufacturing, 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. In September 2008, Biotest began Phase 1 evaluation of indatuximab ravtansine which triggered a $500,000 milestone payment to the Company. The next potential milestone the Company will be entitled to receive will be a development milestone for commencement of a Phase 2b clinical trial (as defined in the agreement) which will result in a $2 million payment being due.

Bayer

In 2008, the Company granted Bayer an exclusive development and commercialization license to the Company’s maytansinoid ADC 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 which was recognized as revenue ratably over the Company’s estimated period of substantial involvement which concluded in September 2012. For each compound developed and marketed by Bayer under this collaboration the Company is entitled to receive a total of $170.5 million in milestone payments, plus tiered royalties between 4 - 7% 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 December 31, 2019, the Company has received and recognized an aggregate of $13 million in milestone payments under this agreement. In July 2017, Bayer announced that its Phase 2 clinical study did not meet its primary endpoint of progression-free survival. The safety and tolerability of anetumab ravtansine were consistent with earlier clinical findings and Bayer is continuing development in additional studies, including a Phase 1b multi-indication study in six different types of advanced solid tumors, and a Phase 1b combination-study in patients with recurrent platinum-resistant ovarian cancer. The next potential milestone the Company will be entitled to receive will be either a development milestone for commencement of a pivotal clinical trial for a second indication for anetumab ravtansine which will result in a $2 million payment being due or a regulatory milestone for filing of regulatory approval for its first indication for anetumab ravtansine which will result in a $6 million payment being due.

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. The total milestones are categorized as follows: development milestones—$22.5 million; regulatory milestones—$77 million; and sales milestones—$100 million. The initial three-year term of the right-to-test agreement was extended by Novartis in October 2013 for an additional one-year period by payment of a $5 million fee to the Company. The Company also is entitled to receive payments for research and development activities performed on behalf of Novartis. Novartis is responsible for the manufacturing, development, and marketing of any products resulting from this agreement.

In March 2013, the Company and Novartis amended the right-to-test agreement so that Novartis could take a license to develop and commercialize products directed at two undisclosed, related 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 no longer be converted to an exclusive target due to the expiration of the right-to-test agreement. The Company received a $3.5 million fee in connection with the execution of the amendment to the agreement.

In connection with the amendment, in March 2013, the Company granted Novartis 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 received a $1 million upfront fee with the execution of this license. In May 2018, Novartis terminated the license. 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 year ended December 31, 2018.

In October 2013 and November 2013, the Company granted Novartis its second and third exclusive licenses to single targets, and in October 2014, the three remaining exclusive licenses, each triggering a $1 million upfront payment to the Company and the opportunity to receive milestone payments totaling $199.5 million, as outlined above, plus royalties on the commercial sales of any resulting products. In January 2015 and May 2015, Novartis initiated Phase 1, first-in-human clinical testing of its cKit-targeting ADC product candidate, LOP628, and P-cadherin-targeting ADC product candidate, PCA062, respectively, triggering a $5 million development milestone payment to the Company with each event. In December 2016, Novartis initiated Phase 1, first-in-human clinical testing of its CDH6-targeting ADC product candidate, HKT288, triggering a $5 million milestone payment which the Company received in 2017. Novartis later discontinued clinical testing of these three products. In December 2019, a development milestone related to dosing a first patient in a Phase 1 clinical trial for a separate licensed product became probable of being attained. Accordingly, $4.7 million of the $5.0 million milestone that was allocated to the delivered license was recorded as revenue and is included in license and milestone fees for the year ended December 31, 2019, and $0.3 million that was allocated to future technological improvements was deferred and will be recognized as revenue ratably over the estimated term of the license. The next potential payment the Company could receive would be either a $7.5 million development milestone for commencement of a Phase 2 clinical trial or a $5 million development milestone for commencement of a Phase 1 clinical trial.

Lilly

The Company granted Eli Lilly and Company (Lilly) three exclusive development and commercialization licenses under a now-expired right-to-test agreement established in 2011. The Company received a $20 million upfront payment in connection with the execution of the right-to-test agreement in 2011. Under the terms of this right-to-test agreement, the first license had no associated exercise fee, and the second and third licenses each had a $2 million exercise fee. The first development and commercialization license was granted in August 2013 and the agreement was amended in December 2013 to provide Lilly with an extension provision and retrospectively include a $2 million exercise fee for the first license in lieu of the fee due for either the second or third license. The second and third licenses were granted in December 2014, with one including the $2 million exercise fee and the other not. In October 2018, Lilly terminated its three development and commercialization licenses. As a result, the Company recorded the remaining $692,000 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 year ended December 31, 2018.

CytomX

In 2016, the Company granted CytomX an exclusive development and commercialization license to the Company’s maytansinoid ADC technology for use with Probodies™ that target CD166 under a now expired reciprocal right-to-test agreement. The Company neither received nor made an upfront cash payment in connection with the execution of the right-to-test agreement or the license agreement. An amendment of the agreement executed simultaneously with the license, granted CytomX the right, for a specified period of time, to substitute the specified target with another as yet unspecified target. Accordingly, the revenue associated with this license was deferred until the expiration of that substitution right in January 2017, whereupon the Company recognized $12.7 million of the $13 million of arrangement consideration allocated to the development and commercialization license, which is included in license and milestone fee revenue for the year ended December 31, 2017. With respect to the development and commercialization license granted to CytomX, the Company is entitled to receive up to a total of $160 million in milestone payments plus royalties on the commercial sales of any resulting product. The total milestones are categorized as follows: development milestones—$10 million; regulatory milestones—$50 million; and sales milestones—$100 million. In June 2017, CytomX enrolled its first patient in a Phase 1 clinical trial for its product candidate, CX-2009, triggering a $1 million development milestone payment which is included in license and milestone fee revenue for the year ended December 31, 2017. In December 2019, a development milestone related to dosing of a first patient in a Phase 2 clinical trial became probable of being attained, which resulted in $3.0 million of license and milestone fee revenue being recorded in 2019. On February 21, 2020, CytomX notified the Company that it had enrolled its first patient in the aforementioned Phase 2 clinical trial. The next payment the Company could receive would be a $6 million development milestone payment with commencement of a Phase III clinical trial. CytomX is responsible for the manufacturing, development, and marketing of any products resulting from the development and commercialization license taken by CytomX under this collaboration.

Costs directly attributable to the CytomX collaborative agreement are comprised of compensation and benefits related to employees who provided research and development services on behalf of CytomX as well as costs of clinical materials sold. Indirect costs are not identified to individual collaborators. The costs related to the research and development services amounted to $195,000 and $256,000 for the years ended December 31, 2018 and 2017, respectively. The costs related to clinical materials sold were $3.5 million and $1.0 million for the years ended December 31, 2018 and 2017, respectively. There were no similar costs recorded subsequently.

In 2017, we took exclusive development and commercialization licenses to CytomX’s proprietary antibody-masking (Probody) technology for use with Probodies that target two specified targets under the same reciprocal right-to-test agreement. The Company terminated one of these licenses for convenience prior to the end of 2017, and terminated the second license in December 2019 in connection with the grant of the EpCAM license to CytomX discussed further below. No upfront cash payments were made by the Company with the execution of these license agreements.

The arrangement was accounted for based on the fair value of the items exchanged. The items to be delivered to CytomX under the arrangement are accounted for under the Company’s revenue recognition policy. The items that were received from CytomX were recorded as research and development expenses as incurred.

In December 2019, the Company granted CytomX an exclusive development and commercialization license to maytansinoid and IGN ADC technology for use with Probodies™ that target EpCAM. Pursuant to the license agreement, in January 2020, the Company received a $7.5 million upfront payment, of which $7.3 million was recorded as license and milestone fee revenue upon delivery of the license to CytomX in December 2019 and $200,000 was deferred until delivery of certain materials as these performance obligations were determined to be distinct. The Company is also

entitled to receive up to a total of $355 million in milestone payments plus royalties on the commercial sales of any resulting product. The total milestones are categorized as follows: development milestones—$35 million; regulatory milestones—$170 million; and sales milestones—$150 million. CytomX is responsible for the manufacturing, product development, and marketing of any products resulting from this license.

Takeda

In March 2015, the Company entered into a three-year right-to-test agreement with Takeda Pharmaceutical Company Limited (Takeda) through its wholly owned subsidiary, Millennium Pharmaceuticals, Inc. The agreement provides 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 by the end of the term of the right-to-test agreement, after which any then outstanding options would lapse. Takeda had the right to extend the three-year right-to-test period for one additional year by payment to the Company of $4 million. Alternatively, Takeda had the right to expand the scope of the right-to-test agreement by payment to the Company of $8 million. Takeda is responsible for the manufacturing, development, and marketing of any products resulting from this collaboration.

The Company received a $20 million upfront payment in connection with the execution of the right-to-test agreement and, for each development and commercialization license taken, is entitled to receive up to a total of $210 million in milestone payments, plus royalties on the commercial sales of any resulting products. The total milestones are categorized as follows: development milestones—$30 million; regulatory milestones—$85 million; and sales milestones—$95 million. The Company also is entitled to receive payments for delivery of cytotoxic agents to Takeda and research and development activities performed on behalf of Takeda.

A first license was granted to Takeda in December 2015, whereupon the Company recognized $8.6 million of the arrangement consideration allocated to the development and commercialization licenses. In March 2018, the right-to-test agreement expired without Takeda exercising its option to a second license or extending the agreement 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 year ended December 31, 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 2 clinical trial.

Costs directly attributable to the Takeda collaborative agreement are comprised of compensation and benefits related to employees who provided research and development services on behalf of Takeda. Indirect costs are not identified to individual collaborators. The costs related to the research and development services amounted to $199,000 and $913,000, for the years ended December 31, 2018 and 2017, respectively. The costs related to clinical materials sold were $650,000 and $2.1 million for the years ended December 31, 2018 and 2017, respectively. There were no similar costs recorded subsequently.

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 year ended December 31, 2018, a development milestone related to dosing of a first patient in a Phase I clinical trial became probable of being attained, which resulted in a $500,000 contract asset and the related license and milestone fee revenue being recorded in that year. It 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, development, and marketing of any products resulting from the license.

Debiopharm

In May 2017, Debiopharm International SA (Debiopharm) acquired the Company’s IMGN529 program, a clinical-stage anti-CD37 ADC for the treatment of patients with B-cell malignancies, such as non-Hodgkin lymphomas (NHL). 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 and a $5 million milestone payment upon substantial completion of the transfer of ImmunoGen technologies related to the program (technology transfer), which was completed in the fourth quarter of 2017. $4.5 million was received for this milestone in December 2017, and the balance in January 2018 upon delivery of the final materials related to the transfer. Accordingly, the Company recorded $500,000 and $29.5 million of license and milestone fee revenue in 2018 and 2017, respectively. In addition, ImmunoGen 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 a Phase 3 trial using the Company’s technology but not the IMGN529 antibody commences prior to IMGN529 entering a Phase 3 trial. The Company does not believe this scenario is likely to occur.

Jazz Pharmaceuticals

In August 2017, the Company entered into a Collaboration and Option Agreement (the “Option Agreement”) with Jazz Pharmaceuticals Ireland Limited (Jazz), a subsidiary of Jazz Pharmaceuticals plc, granting Jazz exclusive, worldwide rights to opt into development and commercialization of two early-stage, hematology-related ADC programs, as well as an additional program to be designated during the term of the agreement. The programs covered under the agreement included IMGN779, a CD33-targeted ADC for the treatment of acute myeloid leukemia (AML) then in Phase 1 testing, IMGN632, a CD123-targeted ADC for hematological malignancies also then in Phase 1 testing, and an early-stage program to be determined at a later date.

In October 2019, Jazz exercised certain of its opt-out rights under the Option Agreement following the termination of the Company’s IMGN779 development program. In addition, in November 2019, the Company executed a First Amendment (the “First Amendment”) to the Option Agreement. The First Amendment included an exercise of their opt-out rights related to the termination of the Company’s early research programs covered by the Option Agreement in connection with the Company’s previously announced restructuring. Under the terms of the Option Agreement, the exercise of both of these opt-out rights will result in a pro-rata reduction in Jazz’s obligation to provide development funding, which will now be limited to support of the Company’s IMGN632 development program. The First Amendment also provides for a streamlining of the governance structure under the Option Agreement and a reduction in the option exercise fee that Jazz would pay for the remaining product under the Option Agreement or a back-up to that product.

As part of the Option agreement, Jazz made an upfront payment of $75 million to the Company. Additionally, Jazz had also agreed to pay the Company up to $100 million in development funding over seven years to support the three ADC programs. That obligation has now been reduced for years 2020 through 2024 pursuant to the terms of the First Amendment. Jazz may exercise its option with respect to IMGN632 at any time prior to a pivotal study or at any time prior to the filing of a biologics license application (BLA) upon payment of an option exercise fee of mid-double digit millions or low triple digit millions, respectively. Following any opt-in, Jazz would be generally responsible for any further development as well as for potential regulatory submissions and commercialization and Jazz and the Company would share costs associated with developing and obtaining regulatory approvals of the applicable product in the U.S. and EU. If Jazz elects to opt-in to IMGN632, the Company would be eligible to receive milestone payments based on receiving regulatory approvals aggregating $100 million plus tiered royalties as a percentage of commercial sales by Jazz, which will vary depending upon sales levels and the stage of development at the time of opt-in. The Company has the right to co-commercialize IMGN632 in the U.S. with profit sharing in lieu of Jazz's payment of the U.S. milestone and royalties to the Company.

Due to the involvement the Company and Jazz both had in the development and commercialization of the products, as well as both parties being part of the cost share agreement and exposed to significant risks and rewards dependent on the commercial success of the products, the arrangement was determined to be a collaborative arrangement within the scope of ASC 808. Accordingly, the Company carved out the research and development activities and the related cost sharing arrangement with Jazz. Payments for such activities are recorded as research and development expense and reimbursements received from Jazz are recognized as an offset to research and development expense in the accompanying statement of operations during the development period. Included in research and development expense for the years ended December 31, 2019, 2018 and 2017, are $12.5, $10.0 and $3.3 million of credits related to reimbursements from Jazz, respectively.

The non-refundable, upfront arrangement consideration of $75 million was allocated to the three License Options. The amount allocated to the rights to future technological improvements under the relative selling price method was deemed immaterial and, therefore, not segregated from the License Options. In conjunction with the opt-out of IMGN779, the Company recognized $14.5 million of the deferred revenue in the year ended December 31, 2019. In connection with the execution of the First Amendment, the amount of the transaction price originally allocated to the

early research product Options was reallocated to the to the IMGN632 Option, which represents the only remaining material right. The amount allocated to the IMGN632 option will be recognized as revenue when exercised by Jazz or upon expiration. The Company does not control when Jazz will exercise its option for its development and commercialization license. As a result, the Company cannot predict when it will recognize revenue related to the delivery of the license and, accordingly, the remaining upfront payment of $60.5 million is included in long-term deferred revenue as of December 31, 2019.