On May 21st, 2021, the Food and Drug Administration (FDA) approved Rybrevant (amivantamab-vmjw) for treatment of advanced non-small cell lung cancer (NSCLC) with a change in EGFR called exon 20 insertion. The FDA based their approval on the results of the clinical trial CHRYSALIS which showed that patients receiving Rybrevant responded to the drug for a year.
In addition to approving Rybrevant, the FDA also granted approval for Guardant360 CDx as a companion diagnostic. Rybrevant marks the first drug to receive approval from the FDA for patients with the exon 20 insertion change delivering hope and a new option to a large population of patients.
is there a difference between exon 21 and exon 20?
Exon 21 and exon 20 describe what specific part of EGFR is mutated, or changed. You can think of EGFR as a page in a book. Exon 21 would refer to a specific paragraph on that page. Exon 20 would refer to a completely different paragraph. Exon 21 and exon 20 are treated with different drugs because of they refer to different parts of EGFR.