Therapeutic selectivity remains a challenge in cancer treatment, despite significant advances in the pharmaceutical industry. Promising therapeutic design candidates often fail to make it past the clinical trial stage, due to toxicity and drug interaction concerns. These failures represent a substantial loss of investment.
To combat this problem, Frederick Gluck, Dr. Nancy Stagliano, and Professor Patrick Daugherty of UCSB’s Department of Chemical Engineering founded CytomX Therapeutics, in 2008. CytomX’s novel Probody® platform, allows for drug designs that selectively activate in the tumor microenvironment while reducing drug activity in healthy tissue and in circulation. CytomX has pioneered a novel class of antibody therapeutics against clinically-validated targets such as PD-L1, as well as cancer therapeutics for targets that are much more difficult to drug, such as the highly expressed tumor antigen, CD166.
In the 17 years since its inception, CytomX has seen extensive growth. Many renowned names in biotech, including AbbVie, Amgen, Bristol-Myers Squibb, Astellas Pharma, ImmunoGen Inc., Pfizer, and the MD Anderson Cancer Center have seen the potential in Probody® therapeutics and have engaged CytomX in strategic partnerships to develop new drugs with their targets. Over these collaborations, CytomX has earned more than $500 million in upfront payments and milestones, and can earn additional milestones, and either royalties or profit splits on all partnered products. In 2025, CytomX announced that the first patient has been dosed with CX-801 in combination with KEYTRUDA® (pembrolizumab), Merck’s anti-PD-1 therapy, in the ongoing Phase 1 dose escalation study evaluating safety and initial clinical activity in patients with metastatic melanoma.