Pyrotinib in Patients with HER2-Amplified Advanced Non–Small Cell Lung Cancer: A Prospective, Multicenter, Single-Arm Trial

Abstract Purpose: In this study, we aimed to evaluate the efficacy and safety of pyrotinib, a pan-HER inhibitor, in patients with HER2-amplified non–small cell lung cancer (NSCLC). Patients and Methods: In this prospective, multicenter, single-arm trial (ChiCTR1800020262), patients with advanced NSCLC with HER2 amplification, as determined by next-generation sequencing, were enrolled and administered pyrotinib orally at 400 mg per day. The primary endpoint was 6-month progression-free survival (PFS) rate. Other endpoints included objective response rate (ORR), disease control rate (DCR), PFS, overall survival (OS), and safety. Results: The enrolled cohort included 27 patients with HER2 amplification. The 6-month PFS rate was 51.9% [95% confidence interval (CI), 34.0–69.3]. The median PFS (mPFS) was 6.3 months (95% CI, 3.0–9.6 months), and median OS was 12.5 months (95% CI, 8.2–16.8 months). Pyrotinib elicited a confirmed ORR of 22.2% (95% CI, 10.6%−40.8%). Patients administered pyrotinib as first-line treatment achieved an mPFS of 12.4 months. Moreover, 30.8% of the patients who had progressed on EGFR tyrosine kinase inhibitor (TKI) responded to pyrotinib. Patients with brain metastases had an ORR of 40%. Treatment-related adverse events (TRAE) occurred in all patients (grade 3, 22.2%), but no grade 4 or higher TRAEs were documented. Diarrhea was the most frequent TRAE (all, 92.6%; grade 3, 7.4%). Loss of HER2 amplification was detected upon disease progression. Conclusions: Pyrotinib provided antitumor efficacy with a manageable safety profile in HER2-amplified patients with NSCLC.