Bristol-Myers initiates new cohort in Phase I/II trial of BMS-986249

25th February 2020 (Last Updated February 25th, 2020 10:40)

Bristol-Myers Squibb (BMS) has launched an expanded Phase II cohort in the ongoing Phase I/IIa clinical trial of CytomX Therapeutics’ anti-CTLA-4 Probody candidate, BMS-986249.

Bristol-Myers initiates new cohort in Phase I/II trial of BMS-986249
3D structure of a melanoma cell derived by ion abrasion scanning electron microscopy. Credit: Sriram Subramaniam, National Cancer Institute, National Institutes of Health.

Bristol-Myers Squibb (BMS) has launched an expanded Phase II cohort in the ongoing Phase I/IIa clinical trial of CytomX Therapeutics’ anti-CTLA-4 Probody candidate, BMS-986249.

BMS-986249 is said to be a peptide masked formulation of Yervoy (ipilimumab), which is also an anti-CTLA-4 antibody.

The Phase I/II study is being conducted to assess the drug candidate alone or in combination with BMS’ Opdivo (nivolumab) for the treatment of solid tumours.

In the new expansion cohort, the combination’s safety and efficacy will be investigated in approximately 375 metastatic melanoma patients.

Primary measures of the study are the incidence of adverse events, serious adverse events, treatment-related Grade 3-5 adverse events, death, laboratory abnormalities, and objective response rate.

The advancement of BMS-986249 into the new part of the study triggers a $10m milestone payment from BMS to CytomX. It is expected that the trial will be completed in 2024.

CytomX Therapeutics president, CEO and chairman Sean McCarthy said: “CTLA-4 is the prototypical checkpoint target and blocking this mechanism has proven highly effective in the treatment of melanoma and other cancer types.

“This ongoing work by the Bristol-Myers Squibb team complements CytomX’s own work and continued clinical progress with the combination of our anti-PD-L1 Probody, CX-072, with ipilimumab, which will further delineate the potential of our Probody therapeutic platform to deliver differentiated anti-cancer therapies.”

In September last year, BMS launched the dose-escalation part of a Phase I/IIa study of another anti-CTLA-4 Probody, BMS-986288. This compound builds on a modified version of ipilimumab.

BMS-986288 is being evaluated as a monotherapy and in combination with nivolumab in around 200 patients with certain advanced solid tumours. The study is set to be completed in 2024.