Oral Plenary Presentation Receives SGO Presidential Award

LOS ANGELES, CA, USA I March 18, 2019 I Puma Biotechnology, Inc. (Nasdaq: PBYI), a biopharmaceutical company, announced today that updated results from the cervical cancer cohort of SUMMIT, an ongoing Phase II basket trial examining the efficacy of neratinib in HER2-mutated cancers, were reported at the Society of Gynecologic Oncology (SGO) 2019 Annual Meeting in Honolulu, Hawaii. “Neratinib in patients with HER2-mutant, metastatic cervical cancer: findings from the phase II SUMMIT ‘basket’ trial,” was presented during the Scientific Plenary Session by Anishka D’Souza, M.D., Assistant Professor of Clinical Medicine, Keck School of Medicine of University of Southern California (USC). SGO selected this abstract as the recipient of the 2019 SGO Presidential Award. Slides from the presentation are available on the Puma Biotechnology website.

The Phase II SUMMIT ‘basket’ trial is an open-label, multicenter, multinational study to evaluate the safety and efficacy of neratinib administered daily to patients who have solid tumors with activating, somatic HER2 mutations. The cervical cancer cohort was comprised of 11 patients with advanced and/or metastatic disease treated with neratinib monotherapy. Patients received a median of 2 (range 1–4) prior regimens in the recurrent or metastatic setting before entering this trial. Six patients (54.5%) had been previously treated with bevacizumab prior to entering the study; 7 patients (63.6%) had received prior surgery; and 9 patients (81.8%) received prior radiation therapy. The objective response rate was 27.3% (95% CI: 6.0%–61.0%). The clinical benefit rate was 54.5% (95% CI: 23.4%–83.3%) and included 3 patients with confirmed partial responses and 3 patients with stable disease that lasted greater than 16 weeks. The median progression free survival was 7.0 months (95% CI: 0.7–20.1 months).

The safety profile observed in neratinib-treated cervical cancer patients in SUMMIT was consistent with that reported for HER2-amplified metastatic breast cancer. The most frequently observed adverse event was diarrhea, any grade (n=9, 81.8%) including 1 (9%) grade 3 diarrhea event. The duration of grade 3 diarrhea was 1 day. None of the diarrhea events resulted in dose reduction, dose discontinuation or hospitalization.

“Somatic HER2 mutations represent a distinct class of oncogenic driver mutations that appear to be clinically actionable for metastatic cervical cancers. Treatment with neratinib led to durable responses and disease control in metastatic patients with HER2-mutant cervical cancer,” said Dr. D’Souza, who practices oncology at the USC Norris Comprehensive Cancer Center.

Alan H. Auerbach, CEO and President of Puma Biotechnology, added, “We are very pleased with the activity seen with neratinib in this cohort of patients with HER2-mutated cervical cancer. We look forward to the further development of neratinib in this patient population.”

About Puma Biotechnology

Puma Biotechnology, Inc. is a biopharmaceutical company with a focus on the development and commercialization of innovative products to enhance cancer care. Puma in-licenses the global development and commercialization rights to three drug candidates — PB272 (neratinib, oral), PB272 (neratinib, intravenous) and PB357. Neratinib, oral was approved by the U.S. Food and Drug Administration in July 2017 for the extended adjuvant treatment of adult patients with early stage HER2-overexpressed/amplified breast cancer, following adjuvant trastuzumab-based therapy, and is marketed in the United States as NERLYNX® (neratinib) tablets. NERLYNX was granted marketing authorization by the European Commission for the extended adjuvant treatment of hormone receptor-positive HER2-positive early stage breast cancer in September 2018. NERLYNX is a registered trademark of Puma Biotechnology, Inc.

SOURCE: Puma Biotechnology