6. Collaboration and License Agreements

Amgen, Inc.

On September 29, 2017, the Company entered into a Collaboration and License Agreement with Amgen, Inc. (the "Amgen Agreement") pursuant to which the parties collaborated on the research, development, and commercialization of conditionally activated T-cell engager ("TCE") therapies, including CX-904, an EGFR-targeting TCE candidate. In connection with the agreement, the Company received a $40.0 million upfront payment and $20.0 million from Amgen's purchase of the Company's common stock, with CytomX responsible for certain early-stage development activities and Amgen responsible for late-stage development and commercialization of selected programs.

Following FDA clearance of the IND for CX-904 in 2022 and advancement into Phase 1 clinical development, CytomX and Amgen jointly discontinued the program in March 2025. Effective the second quarter of 2025, Amgen terminated its rights to both the EGFR program and an additional Amgen-selected target, resulting in the recognition of all remaining deferred revenue associated with these programs by June 30, 2025. As of June 30, 2025, the Company had completed its performance obligations under the Amgen Agreement.

At the initiation of the collaboration, CytomX had the option to select from programs specified in the Amgen Agreement, an existing preclinical stage TCE product from the Amgen preclinical pipeline. In March 2018, CytomX selected the program and this program, CX-908, a PROBODY T cell engager targeting CDH3 and CD3, is currently in preclinical development. CytomX is responsible, at its expense, for converting this program to a conditionally activated TCE product, and thereafter, will be responsible for development, manufacturing, and commercialization of the product (“CytomX Product”). Amgen is eligible to receive up to $203.0 million in development, regulatory, and commercial milestone payments for the CytomX Product, and tiered mid-single digit to low double-digit percentage royalties.

Astellas Pharma Inc.

On March 23, 2020, the Company entered into a Collaboration and License Agreement with Astellas Pharma Inc. ("Astellas") to research, develop, and commercialize PROBODY therapeutic candidates against up to six oncology targets, including an initial target and potential additional targets. Under the agreement, the Company received an $80.0 million upfront payment and is eligible to receive development, regulatory and commercial milestone payments, as well as tiered royalties on future product sales.

Since inception of the collaboration, the Company has achieved multiple development milestones on selected the collaboration targets, including a $5.0 million payment for the initiation of GLP toxicology studies by Astellas, which was fully recognized in the first quarter of 2025.

In the first quarter of 2026, Astellas chose not to advance the remaining preclinical programs and terminated the Astellas Agreement effective May 12, 2026, which resulted in the completion of the Company's performance obligation and recognition of the remaining deferred revenue by the second quarter of 2026. As a result, a cumulative adjustment of $7.1 million of revenue was recognized in the first quarter of 2026, which lowered the net loss per share by $0.04 for the six months ended June 30, 2026. It has no impact on the net loss per share of the current quarter. As of June 30, 2026, there was no deferred revenue relating to the Astellas Agreement. Deferred revenue was $8.6 million as of December 31, 2025. The amount due from Astellas under the Astellas Agreement was $30 thousand as of June 30, 2026 and $0.9 million as of December 31, 2025.

Bristol Myers Squibb Company

Effective July 7, 2014, the Company entered into a collaboration and license agreement with Bristol Myers Squibb Company ("Bristol Myers Squibb") to discover, develop, and commercialize PROBODY therapeutics against multiple oncology targets, including CTLA-4, which was subsequently expanded in 2017 and amended in 2021 to include additional targets and extended research activities. Under the collaboration, the Company received aggregate upfront and milestone payments of $297.0 million and was eligible for additional development, regulatory, commercial milestone payments, and royalties on future product sales.

In 2024, Bristol Myers Squibb discontinued development of its lead CTLA-4 program, BMS-986288, and reduced the scope of certain preclinical research activities under the collaboration. The Company's research obligations for the remaining programs were completed in April 2025, resulting in recognition of the remaining deferred revenue of $11.6 million, and Bristol Myers Squibb subsequently terminated the collaboration in May 2026 after electing not to advance the remaining preclinical programs.

ModernaTX, Inc.

The Company and ModernaTX, Inc. (“Moderna”) entered into a Collaboration and License Agreement (the “Moderna Agreement”) on December 30, 2022, the effective date, to collaborate on discovery and preclinical research and development activities to create investigational messenger RNA (“mRNA”) based conditionally activated therapies using the Company’s PROBODY therapeutic technology. Moderna is solely responsible for the development (preclinical and clinical), manufacturing, and commercialization of any products under the Moderna Agreement.

Under the terms of the Moderna Agreement, the Company granted Moderna an exclusive, worldwide right to develop and commercialize PROBODY therapeutics for the collaboration programs. In exchange, the Company received an upfront payment of $35.0 million in January 2023, including $5.0 million of prepaid research and development service fees. The Company will continue to receive research and development service fees according to the preclinical research work plans based on a prescribed FTE rate and is eligible to receive up to approximately $1.2 billion in future development, regulatory, and commercial milestone payments. The Company is also eligible to receive tiered royalties from high-single digit to low-teen percentage rates of annual global net sales of any products that are commercialized under the Moderna Agreement.

Due to Moderna's budget considerations, the Company's remaining activities for its performance obligation are currently paused pending future alignment with Moderna. As of June 30, 2026 and December 31, 2025, deferred revenue relating to the Moderna Agreement was $9.3 million and $9.3 million, respectively. There was no amount due from Moderna under the Moderna Agreement as of June 30, 2026 and December 31, 2025.

Regeneron Pharmaceuticals, Inc.

The Company and Regeneron Pharmaceuticals Inc. (“Regeneron”) entered into a Collaboration and License Agreement (the “Regeneron Agreement”) on November 16, 2022, to collaborate on creation of conditionally-activated investigational bispecific cancer therapies utilizing the Company’s PROBODY therapeutic platform and Regeneron’s Veloci-Bi® bispecific antibody development platform. The Company and Regeneron will collaborate on preclinical research and discovery activities for initially agreed upon collaboration programs (“Collaboration Program”) with an option to expand additional Collaboration Programs (“Additional Collaboration Program Option”).

Under the Regeneron Agreement, the Company granted Regeneron an exclusive, worldwide, royalty-bearing license under certain Company intellectual property to develop, manufacture, commercialize and otherwise exploit licensed products (“Licensed Products”) for all human and non-human diagnostic, prophylactic and therapeutic uses in oncology. Regeneron is responsible for funding the cost of preclinical research and discovery activities of both parties for all Licensed Products and for funding the cost of development, manufacturing and commercialization of all Licensed Products worldwide.

Pursuant to the Regeneron Agreement, the consideration from Regeneron was comprised of an upfront fee of $30.0 million, contingent payments for development and regulatory milestones and commercial milestone payments of up to an aggregate of approximately $0.8 billion. If Regeneron exercised its Additional Collaboration Program Option, the Company would have been eligible to receive additional upfront and milestone payments aggregating up to approximately $1.2 billion.

In May 2026, the Company and Regeneron amended the Regeneron Agreement (the "Amendment") primarily to (1) extend the program selection period for Regeneron to select its additional Collaboration Programs for research and development, and (2) expand the total number of additional Collaboration Programs from three to eight targets. Of the eight Collaboration Programs and pursuant to the Amendment, two targets were selected in June 2026 for an aggregate upfront fee of $37.0 million, with contingent payments for development and regulatory milestones and commercial milestone payments of up to an aggregate of approximately $0.8 billion.

Pursuant to the Amendment, if Regeneron exercises all Additional Collaboration Program Options, the Company is eligible to receive total upfront, development, regulatory and commercial milestone payments aggregating up to approximately $4.0 billion. The Company is also entitled to tiered royalties from high-single digit to low-teen percentage royalties from potential future sales. In addition, the Company will receive research and development service fees based on a prescribed FTE rate.

The Company determined that each selected Collaboration Program was a distinct performance obligation consisting of an exclusive research, development and commercialization license, research and development services and participation in the joint research committee. The Company concluded that as of the effective date of the Amendment, the final two targets were material rights and performance obligations. The Company accounted for the Amendment as a contract modification and allocated the total unrecognized transaction price among the identified performance obligations using the relative standalone selling price (“SSP”) of each performance obligation. The total unrecognized transaction price as of the effective date of the Amendment was $56.4 million, consisting of the upfront fee of $37.0 million, estimated research and development service fees of $10.0 million and unrecognized transaction price at the time of the modification of $9.4 million. To determine the SSP, the Company considered observable collaboration transactions, adjusted for differences in stage of development, modality, scope of rights transferred, expected research effort, market conditions, and Company-specific circumstances known as of the modification date. The transaction price allocated to each performance obligation is recognized using an input measure over the estimated research service period of four years consistent with the Company’s related accounting policy. The Company determined that the contingent milestone payments were fully constrained due to the uncertainty in achieving them as of the inception of the Amendment.

As of June 30, 2026 and December 31, 2025, deferred revenue relating to the Regeneron Agreement was $45.4 million and $10.5 million, respectively. The amount due from Regeneron under the Regeneron Agreement was $37.5 million and $0.8 million as of June 30, 2026 and December 31, 2025, respectively. The $37.0 million upfront fee was collected in July 2026.

Contract Liabilities

The Company expects that the $54.7 million of deferred revenue related to the following contracts as of June 30, 2026 will be recognized as revenue based on actual FTE effort and estimated program progress as set forth below. However, the timing of revenue recognition could differ from the estimates depending on facts and circumstances impacting the various contracts, including progress of research and

development, resources assigned to the contracts by the Company or its collaboration partners or other factors outside of the Company’s control.