On May 7, 2026 CytomX Therapeutics, Inc. (Nasdaq: CTMX), a leader in the field of masked, conditionally activated biologics, reported Q1 2026 financial results and provided a business update.

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"CytomX has continued to gain tremendous momentum in 2026 and we remain highly focused on executing against the multiple layers of potential value creation we see for Varseta-M. Our top priority is to advance this highly differentiated, first in class EpCAM ADC into a registrational study in late-line CRC while also investing to unlock the broader potential of Varseta-M in earlier line CRC and other cancers," said Dr. Sean McCarthy, chairman and CEO of CytomX Therapeutics."

Continued Dr. McCarthy, "Strategically, we view Varseta-M as a company-building asset, uniquely enabled by the CytomX PROBODY therapeutic platform. Varseta-M is the only EpCAM targeted ADC in clinical development and is, we believe, ideally positioned to address the large unmet need in colorectal cancer as well as a broad range of EpCAM-expressing tumors. Based on the highly encouraging clinical results presented to-date and Varseta-M’s pan-tumor potential, we plan to execute with speed and focus to maximize benefit for people with cancer."

Pipeline Program Updates:

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

On March 16th 2026, CytomX announced positive data from the ongoing Phase 1 dose expansion study of Varseta-M in patients with advanced colorectal cancer (CRC).
As of April 2026, enrollment into Varseta-M Dose Optimization cohorts was complete, having reached the goal of 40 total patients across the 8.6 mg/kg Q3W and 10 mg/kg Q3W doses1.
Additional Phase 1 Varseta-M data, including data from ongoing dose optimization, is anticipated to be presented in the second half of 2026. This update is expected to support monotherapy dose selection and a potential registrational trial design in late line CRC.
FDA interactions are planned in 2026 with goal of aligning on the potential first registrational study for Varseta-M monotherapy in advanced CRC starting in 1H 2027.
A Phase 1 Varseta-M combination study with bevacizumab in CRC has commenced with an initial focus on determining combination dose(s) for later phase development, including in earlier lines of therapy. Varseta-M doses to be assessed in combination with bevacizumab will include Q2W and Q4W schedules to align with the approved bevacizumab CRC dose of 5 mg/kg Q2W. Initial clinical data are anticipated by 1H 2027.
Phase 1/2 combination study including Varseta-M administered with bevacizumab, 5-fluorouracil, and leucovorin is planned to start in 2H 2026.
Initiation of initial Phase 1 expansion cohort(s) in non-CRC indications is planned for 2H 2026.
CX-801 (PROBODY Interferon alpha-2b)

The CX-801 Phase 1 study in advanced melanoma is ongoing. The CX-801 monotherapy dose escalation portion of the study has reached the fourth dose level.
CX-801 monotherapy has been generally well tolerated at dose levels exceeding the approved dose of unmasked IFNα2b.2
In May 2025, Phase 1 dose escalation of CX-801 in combination with KEYTRUDA (pembrolizumab) was initiated. Dose escalation of CX-801 in combination with KEYTRUDA is currently enrolling the third dose level.
Biomarker data from the CX‑801 monotherapy study in advanced melanoma were presented at the 2025 Society for Immunotherapy of Cancer (SITC) (Free SITC Whitepaper) Annual Meeting, reinforcing CX‑801’s mechanism of action and supporting the ongoing combination trial with KEYTRUDA.
Initial clinical data for CX-801 in combination with KEYTRUDA in advanced melanoma is projected by the end of 2026.
KEYTRUDA is a registered trademark of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA

Corporate and Financial:

Financial:
Completed an equity follow-on offering in March 2026 with gross proceeds of $250 million.
CytomX ended Q1 2026 with $346.7 million of cash, cash equivalents and investments with expected cash runway to at least the second half of 2028.
Research Pipeline and Collaborations:
CytomX has research collaborations with Amgen, Regeneron, and Moderna. Drug discovery programs continue in our research collaborations with a focus on bispecific immunotherapies, including T-cell engagers.
Q1 2026 Financial Results:

Cash, cash equivalents and investments totaled $346.7 million as of March 31, 2026, compared to $137.1 million as of December 31, 2025. Cash as of March 31, 2026 included $234.2 million of net proceeds from the completion of an underwritten public offering in March 2026.

Total revenue was $10.3 million for the quarter ended March 31, 2026, compared to $50.9 million for the first quarter of 2025. The decrease in revenue was driven primarily by the completion of our performance obligations during 2025 in the collaborations with Bristol Myers Squibb and Amgen.

Total operating expense for quarter ended March 31, 2026 was $29.9 million compared to $28.3 million for the first quarter ended March 31, 2025, an increase of $1.6 million.

Research and development expenses increased by $0.4 million during the quarter ended March 31, 2026, to $19.2 million compared to $18.9 million for the quarter ended March 31, 2025. Research and development expenses increased primarily due to increased manufacturing activities for Varseta-M, partially offset by $1.7 million of restructuring expenses incurred in the first quarter of 2025.

General and administrative expenses increased by $1.3 million during the quarter ended March 31, 2026, to $10.7 million, compared to $9.4 million for the quarter ended March 31, 2025. The general and administrative expenses for the first quarter of 2025 included $1.1 million of one-time restructuring expenses.

(Press release, CytomX Therapeutics, MAY 7, 2026, View Source [SID1234665319])