CytomX Therapeutics Announces 2025 Financial Results and Provides Business Update (Form 8-K)

CytomX Therapeutics Announces 2025 Financial Results and Provides

Business Update

- Announced Positive Data from Phase 1 Dose Expansion Study of varsetatug masetecan ("Varseta-M") EpCAM PROBODY® ADC in Patients with Advanced Colorectal Cancer (CRC) -

- FDA interactions targeted for mid-year with goal to align on potential Varseta-M registrational trial design in late line CRC -

- Varseta-M Phase 1 study evaluating combination with bevacizumab initiated; Phase 1b/2 chemotherapy combination study to be initiated by the end of 2026 -

- Initial CX-801 PROBODY Interferon-alpha-2b Phase 1 combination data with KEYTRUDA® (pembrolizumab) in melanoma expected by the end of 2026 -

- Company to host conference call today at 8 a.m. ET / 5 a.m. PT -

SOUTH SAN FRANCISCO, Calif., March 16, 2026 - CytomX Therapeutics, Inc. (Nasdaq: CTMX), a leader in the field of masked, conditionally activated biologics, today announced 2025 financial results and provided a business update.

"Today's encouraging Varseta-M Phase 1 update underscores the program's intentional design and broad potential in CRC as well as other EpCAM-expressing indications. CytomX's top priority in 2026 is to align with the FDA on a registrational path for Varseta-M in late-line CRC. We also plan to accelerate Varseta-M combination studies to benefit CRC patients in earlier lines of treatment," said Sean McCarthy, D.Phil., chief executive officer and chairman of CytomX.

"Our continued and exciting progress with Varseta-M reinforces our leadership in the field of masking and CytomX's ability to unlock true innovation. Our highly focused portfolio strategy is also illustrated by our second clinical program, CX-801. This masked version of Interferon-alpha-2b is being developed initially in advanced melanoma and, we believe, has the potential to become a new centerpiece of combination immunotherapy across multiple cancers. The CX-801 translational and biomarker data presented to date have been very encouraging, and we expect to share initial proof of concept data for the combination with KEYTRUDA® later this year."

Pipeline Program Updates:

Varsetatug masetecan (EpCAM PROBODY Topo-1 ADC, CX-2051)

CX-801 (PROBODY Interferon alpha-2b)

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KEYTRUDA® is a registered trademark of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA

Corporate and Financial:

Full Year 2025 Financial Results:

Cash, cash equivalents and investments totaled $137.1 million as of December 31, 2025, compared to $100.6 million as of December 31, 2024.

Total revenue was $76.2 million for the year ended December 31, 2025, compared to $138.1 million in 2024. The decrease in revenue was driven primarily by the completion of our performance obligations in our collaboration with Bristol Myers Squibb in April 2025 as well as a lower estimated percentage of performance obligation completion for 2025 compared to 2024 in the Moderna, Astellas, and Regeneron collaborations.

In 2025, CytomX remained focused on controlling costs and efficiently progressing its pipeline programs. Total operating expense for 2025 was $98.6 million compared to $113.1 million for 2024, a decrease of $14.5 million.

Research and development expenses decreased by $14.7 million during the year ended December 31, 2025, to $68.7 million compared to $83.4 million for 2024. Research and development expenses decreased primarily due to lower general research and development expenses as a result of our January 2025 restructuring and reduced expenses for CX-904, partially offset by increased manufacturing and clinical spend on Varseta-M.

General and administrative expenses increased by $0.1 million during the year ended December 31, 2025, to $29.8 million, compared to $29.7 million for 2024. The general and administrative expenses for 2025 included $1.1 million of one-time restructuring expenses partially offset by reduced personnel related expenses and legal and consulting related expenses.

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About CytomX Therapeutics, Inc.

CytomX is a clinical-stage, oncology-focused biopharmaceutical company focused on developing novel conditionally activated, masked PROBODY® therapeutics designed to be localized to the tumor microenvironment. By pioneering a novel pipeline of localized biologics, powered by its PROBODY therapeutic platform, CytomX's vision is to create safer, more effective therapies for the treatment of cancer. CytomX's robust and differentiated pipeline comprises therapeutic candidates across multiple treatment modalities including antibody-drug conjugates ("ADCs"), cytokines and T-cell engagers. CytomX's clinical-stage pipeline includes varsetatug masetecan (Varseta-M; CX-2051) and CX-801. Varseta-M is a masked, conditionally activated ADC armed with a topoisomerase-1 inhibitor payload and directed toward epithelial cell adhesion molecule (EpCAM). EpCAM is a highly expressed tumor antigen that has previously been undruggable due to expression on normal tissues. Varseta-M is designed to open a therapeutic window for this high potential target and is initially being developed for the treatment of metastatic colorectal cancer. Varseta-M was discovered in collaboration with ImmunoGen, now part of AbbVie. CX-801 is a masked interferon alpha-2b PROBODY® cytokine with broad potential applicability in traditionally immuno-oncology sensitive as well as insensitive (cold) tumors. CX-801 is initially being developed for the treatment of metastatic melanoma. CytomX has established strategic collaborations with multiple leaders in oncology, including Amgen, Bristol Myers Squibb, Regeneron and Moderna. For more information about CytomX and how it is working to make conditionally activated treatments the new standard-of-care in the fight against cancer, visit www.cytomx.com and follow us on LinkedIn and X (formerly Twitter).

CytomX Therapeutics Forward-Looking Statements