Posted: Friday, January 14, 2022
Previous research has shown that patients with non–small cell lung cancers (NSCLCs) have a 2% to 5% chance of insertion mutations in ERBB2 or HER2 exon 20. These mutations are known to function as oncogenic drivers, and there are no approved targeted treatments for this population. A study published in the Journal of Clinical Oncology reported the effects of poziotinib, an irreversible pan-ERBB inhibitor in a cohort of previously treated patients with HER2 exon 20 insertion–positive NSCLC. Mark A. Socinski, MD, of Advent Health Cancer Institute, Orlando, Florida, and colleagues found that the disease control rate with this targeted agent was 70%, and most patients experienced tumor reduction.
A total of 90 patients with a median of 2 prior lines of treatment between October 2017 and March 2021 were enrolled in this study. Patients received poziotinib (16 mg) once daily in an outpatient setting. The primary endpoint was objective response rate, as evaluated by an independent review committee (Response Evaluation Criteria in Solid Tumors version 1.1). The secondary endpoints were duration of response, disease control rate, progression-free survival, safety, tolerability, and quality of life.
Findings revealed that the objective response rate was 27.8% (95% confidence interval [CI] = 18.9%–38.2%), and the disease control rate was 70% (95% CI = 59.4%–79.2%). Most patients (74%) experienced tumor reduction, and the median progression-free survival was 5.5 months (95% CI = 3.9–5.8 months). The median duration of response was 5.1 months (95% CI = 4.2–5.5 months), and the clinical benefit was seen regardless of the number or types of prior therapy.
However, there were some reported grade 3 or higher treatment-related adverse events that included rash (48.9%), diarrhea (25.6%), and stomatitis (24.4%). Based on these findings, Dr. Socinski and colleagues concluded that poziotinib has antitumor activity and that the HER2 exon 20 insertions offer a valid target for future therapeutic advances in this population.
Disclosure: For full disclosures of the study authors, visit, ascopubs.org.