{"url_path":"/sec/ctmx/8-k/2026-06-03/item-1-01","section_key":"item-1-01","section_title":"Item 1.01 Entry into a Material Definitive Agreement.","topic":"sec","document":{"doc_type":"8-K","doc_date":"2026-06-03","source_url":"https://www.sec.gov/Archives/edgar/data/1501989/0001193125-26-255467-index.html","accession_number":"0001193125-26-255467","cik":"0001501989","ticker":"CTMX","issuer_name":"CytomX Therapeutics, Inc.","edgar_url":"https://www.sec.gov/Archives/edgar/data/1501989/0001193125-26-255467-index.html","primary_entity_key":"0001501989","primary_entity_name":"CytomX Therapeutics, Inc."},"word_count":349,"has_tables":true,"body_markdown":"Item 1.01\n\nEntry into a Material Definitive Agreement.\n\nCytomX Therapeutics, Inc. (the “Company”) previously entered into that certain Collaboration and License Agreement, effective November 16, 2022 (as amended, the “Agreement”), with Regeneron Pharmaceuticals, Inc. (“Regeneron”), providing for the collaboration on the creation of conditionally-activated investigational bispecific cancer therapies utilizing the Company’s Probody® therapeutic platform and Regeneron’s Veloci-Bi® bispecific antibody development platform. On May 29, 2026, the Company and Regeneron entered into Amendment No. 4 to the Agreement (“Amendment No. 4”), effective May 31, 2026, pursuant to which the parties agreed to (i) extend the program selection period within which Regeneron may nominate additional collaboration programs and (ii) provide for the addition of up to eight additional collaboration programs to the Agreement, of which Regeneron has nominated the first two as described below, and the remaining six of which are subject to Regeneron’s exercise of its nomination option and payment of certain per-program nomination fees. Total potential target nomination payments and preclinical, clinical, regulatory and commercial milestones covered under the scope of the Agreement are up to approximately $4 billion. The royalty obligations under the Agreement, including the tiered royalty rates on global net sales of licensed products previously disclosed by the Company, are not modified by Amendment No. 4.\n\nAdditionally, in connection with Amendment No. 4, Regeneron nominated the first two additional collaboration programs under the Agreement, entitling the Company to receive aggregate target nomination payments of $37.0 million.\n\nThe foregoing summary of the material terms of Amendment No. 4 is qualified in its entirety by the full text thereof, a copy of which will be filed as an exhibit to the Company’s Quarterly Report on Form 10-Q for the quarterly period ending June 30, 2026. The Company intends to omit certain confidential portions of Amendment No. 4.\n\n \n\nSIGNATURES\n\nPursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.\n\n \n\n \n\n \nCYTOMX THERAPEUTICS, INC.\n\nDate: June 3, 2026\n \n\n \nBy:\n \n\n/s/ Leslie J.B. Robbins\n\n \n\n \n\n \nLeslie J.B. Robbins\nSenior Vice President, Intellectual Property"}