Puma Biotechnology Presents Interim Results from the Phase II SUMMIT Trial of Neratinib for HER2 (ERBB2) Mutant, Metastatic Cervical Cancer at the Society of Gynecologic Oncology (SGO) 2019 Annual Meeting

March 18, 2019 Off By BusinessWire

Oral Plenary Presentation Receives SGO Presidential Award

LOS ANGELES–(BUSINESS WIRE)–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.

Further information about Puma Biotechnology may be found at www.pumabiotechnology.com.

Forward-Looking Statements

This press release contains forward-looking statements, including
statements regarding the development of Puma’s product candidates. All
forward-looking statements involve risks and uncertainties that could
cause Puma’s actual results to differ materially from the anticipated
results and expectations expressed in these forward-looking statements.
These statements are based on current expectations, forecasts and
assumptions, and actual outcomes and results could differ materially
from these statements due to a number of factors, which include, but are
not limited to, the risk factors disclosed in the periodic and current
reports filed by Puma with the Securities and Exchange Commission from
time to time, including Puma’s Annual Report on Form 10-K for the year
ended December 31, 2018. Readers are cautioned not to place undue
reliance on these forward-looking statements, which speak only as of the
date hereof. Puma assumes no obligation to update these forward-looking
statements, except as required by law.