Clinical efficacy of dacomitinib in rechallenge setting for patients with epidermal growth factor receptor mutant non–small cell lung cancer: A multicenter retrospective analysis (TOPGAN2020‐02)

BACKGROUND: Dacomitinib is the second‐generation epidermal growth factor receptor (EGFR)‐tyrosine kinase inhibitor (TKI) for mutant non–small cell lung cancer (NSCLC). EGFR‐TKIs are often re‐administered in Japan after the disease progression prior EGFR‐TKI. There is little evidence of dacomitinib in rechallenge setting. This study evaluated clinical outcomes of dacomitinib in rechallenge setting. METHODS: Patients who received dacomitinib for advanced EGFR‐mutant NSCLC who had progressed after EGFR‐TKI in nine institutions in Japan were included in the analyses. RESULTS: In total, 43 patients were analyzed. The median progression‐free survival (PFS) was 4.3 months (95% confidence interval [CI], 2.5–5.6). The overall survival (OS) was 10.5 months (95% CI, 7.4–not reached). The overall response rate was 25.5% (95% CI, 13.1–33.7). Subset analysis indicated that patients with EGFR exon 21 L858R showed longer PFS than those with EGFR exon 19 deletion (5.8 vs. 4.1 months) (p = 0.018). The most common adverse events leading to dose modification were diarrhea, paronychia, rash, and oral mucositis. CONCLUSION: In the real practice in Japan, dacomitinib showed a worthwhile treatment option for NSCLC patients with EGFR mutation after failure of previous EGFR‐TKI. The benefit was especially pronounced in patients with the exon 21 mutation.