FDA has granted an accelerated approval to a new dosing regimen of 400 mg every six weeks for Keytruda (pembrolizumab) across all currently approved adult indications, in addition to the current 200 mg every three weeks dosing regimen.
Merck sponsors Keytruda.
The approval was based on pharmacokinetic modeling and exposure-response analyses that compared the predicted exposure of pembrolizumab 400 mg every six weeks to observed exposures of pembrolizumab in patients who received pembrolizumab at 2 mg/kg every three weeks, 200 mg every three weeks, and 10 mg/kg administered every two weeks.
The pharmacokinetic modeling was supported by additional exposure-response analyses across the pembrolizumab development program and an interim analysis of pharmacokinetics and overall response rate in a cohort of patients (Cohort B) enrolled in KEYNOTE-555 (NCT03665597), the company said. Cohort B of Study KEYNOTE-555 was an international, single-arm, multi-center study that enrolled 101 patients with advanced or metastatic melanoma who had not received prior PD-1, PD-L1, or CTLA-4 inhibitors (other than CTLA-4 inhibitors in the adjuvant setting). The ORR was 39% (95% CI: 24, 55) in the first 44 patients enrolled in KEYNOTE-555.
Merck resubmitted supplemental Biologics License Applications to FDA to update the dosing frequency for Keytruda to include a 400 mg Q6W option across all approved adult indications. The results of KEYNOTE-555 supported the resubmission, the comoany said. In the EU, 400 mg Q6W dosing for Keytruda monotherapy was approved by the European Commission in March 2019.
Results from KEYNOTE-555 Cohort B were presented in an online plenary session at the American Association for Cancer Research virtual annual meeting April 28.