Selecting First-Line Therapy in EGFR Exon 20 NSCLC: Toxicity and Monitoring

"Selecting First-Line Therapy in EGFR Exon 20 NSCLC: Toxicity and Monitoring" takes up the practical question of how treatment is chosen once an exon 20 insertion is confirmed.

Dr. Yu explains that chemotherapy with amivantamab remains her preferred option whenever possible, given its longest progression-free and overall survival in PAPILLON. She stresses, however, that patients are not treated in isolation. Performance status, comorbidities, and personal preferences all shape the final decision. Platinum-based chemotherapy brings familiar toxicities, including cytopenias affecting white cells, hemoglobin, and platelets, along with fatigue, nausea, and anorexia.

Amivantamab carries a distinctive profile because it targets both EGFR and MET. EGFR-related effects center on acneiform rash of the scalp, face, or trunk, along with paronychia and nail weakening. MET-related effects include lower-extremity edema, an on-target finding seen across available MET inhibitors in lung cancer. Dr. Yu walks patients through these profiles before deciding. At times she recommends starting with chemotherapy and reserving amivantamab for second line. She recalls a patient with a public-facing job who could not work with a rash, so chemotherapy came first.

Dr. Yu also highlights differences in the timing of adverse events. Chemotherapy toxicities peak during the 4 induction cycles of carboplatin and pemetrexed, then ease during pemetrexed maintenance. With an antibody or targeted therapy given continuously, side effects stay fairly consistent throughout treatment. Both regimens are administered every 3 weeks in clinic, which gives her regular opportunities to check blood work and assess toxicity.

For prevention, she points to the COCOON study, which she considers very impactful. COCOON tested proactive dermatologic management during amivantamab, pairing an oral antibiotic such as doxycycline or minocycline with topical agents and a ceramide-based moisturizer. The regimen reduced both the incidence and severity of rash, and she now prescribes it upfront when starting amivantamab. Patients receiving chemotherapy also get folic acid, vitamin B12, and antiemetics as needed.

Up next, in "Unmet Needs in EGFR Exon 20 NSCLC and Next-Generation Oral TKIs," Dr. Yu examines what drives the cost of care in this population and why a new generation of oral inhibitors was needed.