Sevabertinib in Advanced HER2 -Mutant Non–Small-Cell Lung Cancer

BackgroundHER2 gene mutations occur in 2 to 4% of patients with non–small-cell lung cancer (NSCLC). Sevabertinib is an oral, reversible tyrosine kinase inhibitor that has shown anti-HER2 activity in preclinical models.MethodsWe conducted an open-label, multicenter, multicohort, phase 1–2 study to evaluate sevabertinib at a twice-daily dose of 20 mg in patients with locally advanced or metastatic HER2-mutant NSCLC. Three cohorts were defined according to previous therapy: cohort D comprised previously treated patients who had not received HER2-targeted therapy; cohort E, patients who had previously received HER2-directed antibody–drug conjugates; and cohort F, patients who had not previously received treatment. The primary end point was an objective response, as assessed by blinded independent central review. Secondary end points were duration of response and progression-free survival.ResultsA total of 209 patients received sevabertinib (as of June 27, 2025, the data-cutoff date); the median duration of follow-up was 13.8 months in cohort D, 11.7 months in cohort E, and 9.9 months in cohort F. Among 81 patients in cohort D, an objective response was observed in 64% (95% confidence interval CI, 53 to 75); the median duration of response was 9.2 months (95% CI, 6.3 to 13.5), and the median progression-free survival was 8.3 months (95% CI, 6.9 to 12.3). Among 55 patients in cohort E, an objective response was observed in 38% (95% CI, 25 to 52); the median duration of response was 8.5 months, and the median progression-free survival was 5.5 months. Among 73 patients in cohort F, an objective response was observed in 71% (95% CI, 59 to 81), and the median duration of response was 11.0 months; data on progression-free survival were immature. Grade 3 or higher drug-related adverse events occurred in 31% of the patients. The most common adverse event was diarrhea (in 84 to 91%), with diarrhea of grade 3 or higher occurring in 5 to 23%. Treatment was discontinued by 3% of the patients owing to drug-related adverse events.ConclusionsSevabertinib showed antitumor activity in patients with locally advanced or metastatic HER2-mutant NSCLC. Diarrhea was the most common adverse event. (Funded by Bayer; SOHO-01 ClinicalTrials.gov number, NCT05099172.)