CytomX Therapeutics Launches $250 Million Public Offering for PROBODY Platform Development

Font: Financial Modeling Prep  • Mar 17, 2026

CytomX Therapeutics, Inc. (NASDAQ:CTMX) Announces Proposed $250 Million Public Offering

CytomX Therapeutics, Inc. (NASDAQ:CTMX) is a pioneering company in the field of masked, conditionally activated biologics (PROBODY® therapeutics platform). The company has commenced an underwritten public offering of up to $250 million in shares of common stock and, in lieu of common stock to certain investors, pre-funded warrants, with an option for underwriters to purchase an additional $37.5 million in shares. The funds raised are expected to support the development of CytomX's pipeline, including Varseta-M (varsetatug masetecan; CX-2051), and other programs.

The offering is managed by Jefferies, Piper Sandler, Cantor, and Barclays, with Wedbush PacGrow as co-manager. A shelf registration statement was filed with the U.S. Securities and Exchange Commission on March 16, 2026, and is effective immediately. CytomX's pipeline features Varseta-M, an antibody-drug conjugate (ADC) targeting EpCAM for advanced/metastatic colorectal cancer, developed in collaboration with ImmunoGen, now part of AbbVie. Another candidate, CX-801, is a masked interferon alpha-2b PROBODY® cytokine targeting initially for metastatic melanoma.

CytomX has strategic collaborations with Amgen, Bristol Myers Squibb, Regeneron, and Moderna. The offering's completion depends on market conditions and other factors. On March 16, 2026, alongside the offering announcement and 2025 financial results (which showed positive Varseta-M Phase 1 data in CRC, with confirmed response rates of 32% at 10 mg/kg and 20% at 8.6 mg/kg, plus plans for FDA alignment mid-2026 on potential registrational design), the stock experienced high volatility.

Oppenheimer maintains an "Outperform" rating. As of March 17, 2026, CTMX trades around $5.82–$6.53. CTMX's stock has shown high intraday volatility, with massive volume. The 52-week high is $8.21 (recent) and low of $0.40 (prior periods). The company's market capitalization is approximately $400 million. Trading volume was extremely high (e.g., over 121 million shares on March 16, and millions on March 17), driven by the offering news, earnings update, and positive clinical data. These figures highlight the volatility and potential of CTMX in the biotech sector.