BRIEF—First peptide-drug conjugate promises new option in cancer

Exelixis and Cybrexa Therapeutics have entered into an exclusive collaboration agreement, giving the former the right to buy a first-in-class peptide-drug conjugate (PDC).

The new kind of therapy, dubbed CBX-12 (alphalex exatecan), uses Cybrexa’s proprietary alphalex technology to enhance delivery of a topoisomerase I blocker, exatecan, to tumor cells.

Scientists believe the candidate may have broad utility in people who are not eligible for treatments such as monoclonal antibodies and antibody-drug conjugates (ADC).

Data from an ongoing Phase I trial in metastatic solid tumors showed preliminary anti-tumor activity in a heavily pretreated patient population, including a complete response in a patient with ovarian cancer.

Cybrexa will receive $60 million right away for the option on CBX-12, “pending certain Phase I results.”

The firm could receive an additional $642.5 million in milestones, plus an acquisition fee, if all goes according to plan.