Puma Biotechnology’s Licensing Partner Specialised Therapeutics Asia Receives Regulatory Approval to Commercialize NERLYNX® (neratinib) for Extended Adjuvant Treatment of HER2-Positive Early Stage Breast Cancer

March 18, 2019 Off By BusinessWire

Neratinib becomes the first anti-HER2 treatment to be approved in
Australia, as extended adjuvant therapy for early stage HER2-positive
breast cancer following adjuvant trastuzumab-based therapy.
Treatment with neratinib in the approved indication resulted in a
34% reduction in the risk of invasive disease recurrence or death
versus placebo after patients completed one year of therapy following
a trastuzumab-based regimen.
Further, five-year data shows neratinib reduces the risk of
invasive disease recurrence or death by 42% in women with early-stage,
HER2+/HR+ breast cancer.
Neratinib addresses an unmet medical need, as up to 25% of
HER2-positive early stage breast cancer patients treated with
trastuzumab-based adjuvant therapy experience a recurrence.

LOS ANGELES–(BUSINESS WIRE)–Puma Biotechnology, Inc. (Nasdaq: PBYI) announced that its licensing
partner Specialised Therapeutics Asia (STA) has received marketing
authorization from Australia’s Therapeutic Goods Administration (TGA) to
commercialize NERLYNX® (neratinib) in Australia for the extended
adjuvant treatment of adult patients with early stage
HER2-overexpressed/amplified breast cancer following adjuvant
trastuzumab based therapy. STA has submitted regulatory
applications to gain approval to introduce NERLYNX in Singapore. Further
applications are planned by STA in other countries in South East Asia,
including Malaysia, Brunei, Vietnam and Thailand.

TGA approval was based on the Phase III ExteNET trial, a multicenter,
randomized, double-blind, placebo-controlled trial of neratinib
following adjuvant trastuzumab treatment. Women (n=2,840) with
early-stage HER2-positive breast cancer and within two years of
completing adjuvant trastuzumab were randomized to receive either
neratinib (n=1420) or placebo (n=1420) for one year.

The results of the ExteNET trial demonstrated that after two years of
follow-up, invasive disease-free survival (iDFS) was 94.2% in patients
treated with neratinib compared with 91.9% in those receiving placebo
(HR 0.66; 95% CI: 0.49, 0.90, p=0.008).

The most common adverse reactions (>5%) were diarrhea, nausea, abdominal
pain, fatigue, vomiting, rash, stomatitis, decreased appetite, muscle
spasms, dyspepsia, AST or ALT increase, nail disorder, dry skin,
abdominal distention, weight loss, and urinary tract infection. The most
common adverse reaction leading to discontinuation was diarrhea, which
was observed in 16.8% of neratinib-treated patients. Hepatotoxicity or
increases in liver transaminases led to drug discontinuation in 1.7% of
neratinib-treated patients.

“TGA approval marks the first time Australian women are being presented
with an opportunity for extended-adjuvant therapy that will
reduce the risk of disease recurrence in patients who would otherwise
have had a relapse,” said Carlo Montagner, Chief Executive Officer of
Specialised Therapeutics. “We are pleased to be at the forefront of this
new treatment paradigm and look forward to changing outcomes for these
women and their families.”

Puma Biotechnology’s CEO and President, Alan H. Auerbach, added,
“Reducing the risk of disease recurrence remains a need for patients,
despite advances in the treatment of early stage HER2-positive breast
cancer. We are pleased that our partner STA will be bringing this new
medicine to patients throughout Australia and would like to express our
appreciation to the patients, caregivers and physicians who contributed
to the neratinib clinical development program and, more specifically,
the ExteNET trial. We are committed to continuing to expand NERLYNX
accessibility to patients around the world.”

About HER2-Positive Breast Cancer

Approximately 20 to 25 percent of breast cancer tumors over-express the
HER2 protein. HER2-positive breast cancer is often more aggressive than
other types of breast cancer, increasing the risk of disease progression
and death. Although research has shown that trastuzumab can reduce the
risk of early stage HER2-positive breast cancer returning after surgery,
up to 25% of patients treated with trastuzumab experience recurrence.

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.

Important Safety Information Regarding NERLYNX^®(neratinib)
U.S. Indication

NERLYNX® (neratinib) tablets, for oral use

INDICATIONS AND USAGE: NERLYNX is a kinase inhibitor indicated
for the extended adjuvant treatment of adult patients with HER2
overexpressed/amplified breast cancer, to follow adjuvant
trastuzumab-based therapy.

CONTRAINDICATIONS: None

WARNINGS AND PRECAUTIONS:

• Diarrhea: Aggressively manage diarrhea occurring despite
recommended prophylaxis with additional antidiarrheals, fluids, and
electrolytes as clinically indicated. Withhold NERLYNX in patients
experiencing severe and/or persistent diarrhea. Permanently discontinue
NERLYNX in patients experiencing Grade 4 diarrhea or Grade ≥ 2 diarrhea
that occurs after maximal dose reduction.

• Hepatotoxicity: Monitor liver function tests monthly for the
first 3 months of treatment, then every 3 months while on treatment and
as clinically indicated. Withhold NERLYNX in patients experiencing Grade
3 liver abnormalities and permanently discontinue NERLYNX in patients
experiencing Grade 4 liver abnormalities.

• Embryo-Fetal Toxicity: NERLYNX can cause fetal harm. Advise
patients of potential risk to a fetus and to use effective contraception.

ADVERSE REACTIONS: The most common adverse reactions (≥ 5%) were
diarrhea, nausea, abdominal pain, fatigue, vomiting, rash, stomatitis,
decreased appetite, muscle spasms, dyspepsia, AST or ALT increase, nail
disorder, dry skin, abdominal distention, epistaxis, weight decreased
and urinary tract infection.

To report SUSPECTED ADVERSE REACTIONS, contact Puma Biotechnology,
Inc. at 1-844-NERLYNX (1-844-637-5969) and www.NERLYNX.com
or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

DRUG INTERACTIONS:

Gastric acid reducing agents: Avoid concomitant use with proton pump
inhibitors (PPI) and H2-receptor antagonists. Separate NERLYNX by 3
hours after antacid dosing.
Strong or moderate CYP3A4 inhibitors: Avoid concomitant use.
Strong or moderate CYP3A4 inducers: Avoid concomitant use.
P-glycoprotein (P-gp) substrates: Monitor for adverse reactions of
narrow therapeutic agents that are P-gp substrates when used
concomitantly with NERLYNX.

USE IN SPECIFIC POPULATIONS:

Lactation: Advise women not to breastfeed.

Please see Full
Prescribing Information for additional safety information.

To help ensure patients have access to NERLYNX, Puma has implemented the
Puma Patient Lynx support program to assist patients and health care
providers with reimbursement support and referrals to resources that can
help with financial assistance. More information on the Puma Patient
Lynx program can be found at www.NERLYNX.com
or 1-855-816-5421.

The recommended dose of NERLYNX is 240 mg (six 40 mg tablets) given
orally once daily with food, continuously for one year. Antidiarrheal
prophylaxis should be initiated with the first dose of NERLYNX and
continued during the first 2 months (56 days) of treatment and as needed
thereafter.

Forward-Looking Statements

This press release contains forward-looking statements, including
statements regarding the worldwide expansion of NERLYNX. All
forward-looking statements 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 risk factors disclosed in the
periodic and current 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, 2018. 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.