Blueprint Medicines: FDA puts partial clinical hold on the Phase 1/2 VELA trial

Blueprint Medicines announced that the U.S. FDA verbally informed the company on February 8 that it has placed a partial clinical hold on the Phase 1/2 VELA trial of BLU-222 due to visual adverse events observed in a limited number of patients. Patients currently enrolled in the trial are continuing on study drug at this time, and additional patients will not be enrolled until the partial clinical hold is resolved. BLU-222 is currently being evaluated in the Phase 1 dose escalation portion of the VELA trial. Patients have been treated with BLU-222 at doses ranging from 50 mg BID to 800 mg BID to date, with evidence of clinical benefit observed and no discontinuations due to AEs. The reported visual AEs consisted of transient, reversible episodes of light sensitivity and blurred vision. All events were Grade 1, except one Grade 3 event involving light sensitivity and blurred vision in a patient treated at 600 mg BID. All events resolved with dose interruption or reduction. No treatment-emergent abnormal findings, including uveitis, have been observed in patients who have received detailed ophthalmologic examinations. "Patient safety is our first priority, and we are working closely with the FDA to investigate the reported visual adverse events as well as amend the VELA trial protocol to provide specific guidance to investigators on how to monitor for and manage these events should they occur," said Becker Hewes, M.D., Chief Medical Officer at Blueprint Medicines. "We have confidence in the benefit-risk profile of BLU-222 based on the activity and safety data we have seen to date in the dose escalation study. In addition, we recognize the urgency to treat patients with CDK2-vulnerable cancers, many of whom have seen their disease progress after exhausting all other options, and we aim to resume enrollment as expeditiously and responsibly as possible." Consistent with prior guidance, Blueprint Medicines plans to present initial dose escalation data from the VELA trial of BLU-222 in the first half of 2023.