The immune checkpoint inhibitor pembrolizumab, first approved by the US Food and Drug Administration (FDA) in 2014, is a standard treatment for nearly 20 diseases. Registrational pembrolizumab trials administered doses every 3 weeks (standard interval) of 200 mg (flat) or 2 mg per kg (weight based).
1 Pharmacokinetic modeling
2 led the European Medicines Agency to approve 400 mg every 6 weeks dosing (extended interval) of pembrolizumab in March 2019.
1 The FDA rejected a supplemental biologics license application for extended-interval pembrolizumab in February 2020 owing to concern that lower trough concentrations would reduce efficacy.
3 However, the FDA reversed course in April 2020, approving extended-interval pembrolizumab after preliminary nonprespecified analysis of KEYNOTE-555 cohort B—a single-arm cohort of patients outside of the US (n = 44) receiving extended-interval pembrolizumab for melanoma—demonstrated response and immune-related adverse event rates approximately equivalent to historic standard-interval controls.
4