Use of pembrolizumab among older adults with cancer in the United States, before and after FDA approval of its tumor‐agnostic indication

Abstract

AbstractIntroductionPembrolizumab, an anticancer immunotherapy agent, has received multiple approvals since its first approval by the U.S. Food and Drug Administration (FDA) in 2014. Limited data exist on its real‐world use and shifts post tumor‐agnostic approval in 2017 for the treatment of patients with any microsatellite instability‐high/mismatch repair deficient (MSI‐H/dMMR) solid tumors. This study analyzes pembrolizumab's pre and post‐tumor‐agnostic approval use among older U.S. adults, revealing its evolving role in oncology practice.MethodsUsing the Surveillance, Epidemiology and End Results (SEER)‐Medicare data (2014–2019), we examined the cancer sites of pembrolizumab recipients before and after tumor‐agnostic approval. Cancer sites were classified based on the timing of site‐specific approvals (before/after tumor‐agnostic approval) or no site‐specific approval, and inclusion in MSI‐H/dMMR clinical trials.ResultsThe total number of pembrolizumab recipients increased from 4221 in the pre‐agnostic period to 20 479 in the post‐agnostic period. Pembrolizumab was used for a broad range of cancer types, including cancers that had no FDA‐approved site‐specific indications at the time of use (25.8% in pre‐ and 24.6% in post‐agnostic periods). The proportion of pembrolizumab recipients receiving pembrolizumab for cancers with site‐specific approvals before tumor‐agnostic approval decreased from 77.3% to 70.8%. The proportion of pembrolizumab recipients receiving pembrolizumab for cancers that gained site‐specific approvals following tumor‐agnostic approval almost doubled (6.8% to 13.0%). The proportion of pembrolizumab recipients with cancers included in MSI‐H/dMMR trials also doubled (12.3% to 25.5%) following tumor‐agnostic approval.ConclusionsPembrolizumab use has expanded over time among older adults with cancer, extending beyond those with FDA‐approved site‐specific indications.