Puma Biotechnology, Inc. (NASDAQ: PBYI), a biopharmaceutical company, presented updated findings from the Phase II SUMMIT basket trial of neratinib for EGFR exon 18-mutant non-small cell lung cancer (NSCLC) patients at the EORTC/NCI/AACR Molecular Targets and Cancer Therapeutics Symposium that is taking place in Barcelona, Spain. The poster, entitled, "Neratinib efficacy in patients with EGFR exon 18-mutant non-small cell lung cancer: findings from the SUMMIT basket trial," was presented by Alejandro MartÃnez Bueno, Head of Medical Oncology Service, Hospital Quirón Deuxes, Barcelona, Spain, on October 27 beginning at 10:00 a.m. CEST.
The Phase II SUMMIT ‘basket’ trial is an open-label, multicenter, multi-national study evaluating the safety and efficacy of neratinib administered daily to patients who have solid tumors with activating, EGFR exon 18 or HER2 mutations. In the EGFR exon 18-mutant cohort, patients with lung cancer with single or complex EGFR exon 18 mutations, who were EGFR tyrosine kinase inhibitor (TKI) naïve or were previously exposed to EGFR TKI, were enrolled into this study and received 240 mg of neratinib monotherapy once daily. Anti-diarrheal prophylaxis with loperamide was required for the first 2 cycles.
This cohort of 29 patients had received 1-6 prior lines of therapy in the metastatic setting before entering the trial. Twenty-three patients (79%) had been previously treated with an EGFR-targeted TKI (e.g., afatinib, osimertinib).
The interim efficacy results showed that the objective response rate (ORR) was 35% overall, 30% in patients pretreated with TKIs, and 50% in patients not pretreated with TKIs. Response or stable disease lasting for ≥ 48 weeks was observed in 7 patients (6 PR, 1 SD). Final data will be presented at a later date.
The safety profile observed in the cohort of patients with EGFR exon 18-mutant NSCLC showed that for the 31 patients who received at least one dose of neratinib, diarrhea, constipation, and nausea were the most commonly reported adverse events. There were no reports of grade 4 diarrhea, 3 patients (10%) reported grade 3 diarrhea, and 1 patient (3%) permanently discontinued neratinib due to diarrhea.
