CytomX bags $20M for its novel antibodies with Pfizer leading the charge

CytomX CEO Sean McCarthy

South San Francisco oncology specialist CytomX raised a $20 million C round to advance its in-house pipeline of novel cancer treatments, with partner Pfizer ($PFE) pouring in the lion's share of the new cash.

Pfizer Venture Investments led the round, joined by previous backers Third Rock Ventures, Canaan Partners and the Roche ($RHHBY) Venture Fund, giving CytomX the money it needs to hit the gas on its unpartnered oncology therapies. The company's banner technology is designed to generate Probodies, which are antibodies that can lay dormant in healthy tissue and activate only when they run into tumors. That creates a wealth of opportunities to attack some tough targets in cancer, CytomX said, and the biotech has an early-stage pipeline focused on immunotherapies and antibody-drug conjugates.

Leading the way is a preclinical treatment that ties a tumor-seeking Probody to a cancer-killing drug and targets the body's Notch pathway, which is linked to breast, prostate, pancreatic and blood cancers. Then there's a discovery-stage immunotherapy program that hopes to create more tolerable checkpoint inhibitors by applying CycomX's proprietary antibodies to targets like PD-1 and PD-L1, and a second Probody-drug conjugate project designed to create a new generation of less toxic treatments.

"CytomX continues to make significant progress with our Probody platform, and that effort has resulted in a compelling pipeline of wholly owned and partnered Probody therapeutics," CEO Sean McCarthy said in a statement. "The proceeds from this financing will help enable CytomX to advance our proprietary pipeline of Probody drug conjugates and Probodies against cancer immunotherapy checkpoint targets towards the clinic, while we also pursue Probody applications with bispecific antibodies and engineered T cell therapies."

CytomX, a 2013 Fierce 15 winner, is also at work on Probody-driven projects with partners Pfizer, ImmunoGen ($IMGN) and Bristol-Myers Squibb ($BMY).

- read the statement

Special Report: FierceBiotech's 2013 Fierce 15 - CytomX