The Food and Drug Administration (FDA) has granted accelerated approval for Keytruda (pembrolizumab; Merck) for the treatment of advanced or unresectable melanoma in patients who are no longer responsive to other drugs.
It is indicated for use after treatment with ipilimumab (Yervoy; Bristol-Myers Squibb). For patients whose tumors express the BRAF V600 mutation, Keytruda is indicated for use after treatment with ipilimumab and a BRAF inhibitor.
Keytruda is the first PD-1 inhibitor approved, which restricts the immune system from attacking melanoma cells. It is designed to block the interaction of PD-1 on T-cells with its ligands, PD-L1 and PD-L2, to reactivate anti-tumor immunity. It exerts dual ligand blockade of the PD-1 pathway.
Keytruda was granted a breakthrough therapy designation, as well as priority review and orphan product designations.
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Keytruda’s efficacy was established in clinical trial subjects (N=173) with advanced melanoma whose disease progressed after prior treatment. All were treated with Keytruda, either at the recommended dose of 2mg/kg or at a higher dose of 10mg/kg.
In the half of the participants who received Keytruda at the recommended dose of 2mg/kg, about 24% demonstrated tumor shrinkage. This effect lasted at least 1.4–8.5 months and continued beyond this period in most patients. A similar percentage of patients had their tumor shrink at the 10mg/kg dose.
This article originally appeared on MPR