LOS ANGELES--(BUSINESS WIRE)--Puma Biotechnology, Inc. (NYSE: PBYI), a biopharmaceutical company,
announced that results from the ExteNET Phase III clinical trial of
neratinib in patients with early stage HER2 positive breast cancer were
published in the journal The Lancet Oncology. The article
entitled “Neratinib after trastuzumab-based adjuvant therapy in patients
with HER2-positive breast cancer (ExteNET); a multicentre, randomized,
double-blind, placebo-controlled, phase 3 trial” appears in the February
10, 2016 online issue and will be published in a future print issue of
the journal.
The ExteNET trial is a double-blind, placebo-controlled, Phase III trial
of neratinib versus placebo after adjuvant treatment with trastuzumab
(Herceptin) in women with early stage HER2-positive breast cancer. The
trial randomized 2,840 patients in 41 countries with early-stage
HER2-positive breast cancer who had undergone surgery and adjuvant
treatment with trastuzumab. After completion of adjuvant treatment with
trastuzumab, patients were randomized to receive extended adjuvant
treatment with either neratinib or placebo for a period of one year.
Patients were then followed for recurrent disease, ductal carcinoma in
situ (DCIS), or death for a period of two years after randomization in
the trial. The primary endpoint of the trial was invasive disease free
survival (DFS).
The study demonstrated that the trial hit its primary endpoint and that
treatment with neratinib resulted in a 33% reduction of risk of invasive
disease recurrence or death versus placebo (hazard ratio = 0.67, p =
0.009). The 2-year DFS rate for the neratinib arm was 93.9% and the
2-year DFS rate for the placebo arm was 91.6%. For the pre-defined
subgroup of patients with hormone receptor positive disease, the results
of the trial demonstrated that treatment with neratinib resulted in a
49% reduction of risk of invasive disease recurrence or death versus
placebo (hazard ratio = 0.51, p = 0.001). For the patients with hormone
receptor positive disease, the 2-year DFS rate for the neratinib arm was
95.4% and the 2-year DFS rate for the placebo arm was 91.2%.
"ExteNET represents the first randomized trial to demonstrate a
statistically significant DFS benefit using a HER2 targeted drug in the
extended adjuvant treatment of patients with early stage HER2 positive
breast cancer who have previously been treated with adjuvant
trastuzumab," said Alan H. Auerbach, Chief Executive Officer and
President of Puma. "We are pleased that The Lancet Oncology
has chosen to publish these results."
The safety results of the ExteNET study showed that the most frequently
observed adverse event for the neratinib-treated patients was diarrhea,
with approximately 39.9% of the neratinib-treated patients experiencing
grade 3 or higher diarrhea (1 (0.1%) patient had grade 4 diarrhea).
Patients who received neratinib in the ExteNET trial did not receive any
prophylaxis with antidiarrheal agents to prevent the neratinib-related
diarrhea. Recently announced interim results of a Phase II study of
neratinib monotherapy in patients with HER2 positive early stage breast
cancer who have previously been treated with adjuvant trastuzumab where
patients received anti-diarrheal prophylaxis with loperamide
demonstrated that treatment with prophylactic loperamide reduced the
rate of grade 3 or higher diarrhea to between 13.0-18.5%. In addition,
the grade 3 diarrhea that was seen in the interim analysis of this Phase
II trial was limited to the first 3 weeks of the 12 month treatment
period.
About Puma Biotechnology
Puma Biotechnology, Inc. is a biopharmaceutical company with a focus on
the acquisition, development and commercialization of innovative
products to enhance cancer care. The Company aims to acquire proprietary
rights to these products, by license or otherwise, fund their research
and development and bring the products to market. The Company is
initially focused on the development of PB272 (oral neratinib), a potent
irreversible tyrosine kinase inhibitor, for the treatment of patients
with HER2-positive breast cancer and patients with non-small cell lung
cancer, breast cancer and other solid tumors that have a HER2 mutation.
Further information about Puma Biotechnology can be found at www.pumabiotechnology.com.
Forward-Looking Statements:
This press release contains forward-looking statements, including
statements regarding the publication of clinical trial data. All
forward-looking statements included in this press release involve risks
and uncertainties that could cause the Company'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 fact
that the Company has no product revenue and no products approved for
marketing, the Company's dependence on PB272, which is still under
development and may never receive regulatory approval, the challenges
associated with conducting and enrolling clinical trials, the risk that
the results of clinical trials may not support the Company's drug
candidate claims, even if approved, the risk that physicians and
patients may not accept or use the Company's products, the Company's
reliance on third parties to conduct its clinical trials and to
formulate and manufacture its drug candidates, the Company's dependence
on licensed intellectual property, and the other risk factors disclosed
in the periodic reports filed by the Company with the Securities and
Exchange Commission from time to time, including the Company's Annual
Report on Form 10-K for the year ended December 31, 2014 and Quarterly
Reports on Form 10-Q for the quarters ended June 30, 2015 and September
30, 2015. Readers are cautioned not to place undue reliance on these
forward-looking statements, which speak only as of the date hereof. The
Company assumes no obligation to update these forward-looking
statements, except as required by law.
Contact: