Poziotinib for Patients With Exon 20 Mutant Non-Small-Cell Lung Cancer: Results From a Phase II Trial.

Purpose: Targeted therapies against non-small-cell lung cancer (NSCLC) harboring mutations remain an unmet need. In this study, we assessed the efficacy and safety of poziotinib in patients with exon 20 mutant advanced NSCLC in a single-arm, open-label, phase II study.

Patients And Methods: Patients with advanced exon 20 mutant NSCLC were enrolled to receive poziotinib at a dose of 16 mg/d for 28-day cycles. The primary end point was objective response rate per RECIST version 1.1. Confirmatory scans were performed at least 28 days from initial radiologic response.

Results: Thirty patients received poziotinib treatment. At baseline, 90% of patients received prior platinum-based chemotherapy and 53% had two lines or more prior systemic therapies. As of data cutoff on March 1, 2021, the confirmed objective response rate was 27% (95% CI, 12 to 46). Responses were observed across exon 20 mutation subtypes. The median duration of response was 5.0 months (95% CI, 4.0 to not estimable). The median progression-free survival was 5.5 months (95% CI, 4.0 to 7.0). The median overall survival was 15 months (95% CI, 9.0 to not estimable). The most common grade 3 treatment-related adverse events were skin rash (47%) and diarrhea (20%). There was one possible treatment-related death because of pneumonitis.

Conclusion: Poziotinib showed promising antitumor activity in patients with exon 20 mutant NSCLC including patients who had previously received platinum-based chemotherapy.