UC Irvine

Epidermal growth factor receptor (EGFR) exon 20 insertions are a rare subtype of EGFR mutations that do not respond to EGFR tyrosine kinase inhibitors developed for sensitizing mutations. In 2021, two drugs, amivantamab and mobocertinib each received FDA accelerated approval for second line use after platinum based therapy. These drugs were then brought to first line setting clinical trials; PAPILLON and EXCLAIM2. PAPILLON, which compared amivantamab plus chemotherapy to chemotherapy was positive, whereas EXCLAIM2, which compared mobocertinib to chemotherapy was negative. The PAPILLON regimen received subsequent FDA approval. In this commentary, we review the details of PAPILLON and also discuss why the rival trial, EXCLAIM2, may have failed.