Puma Biotechnology and Pierre Fabre Enter into Exclusive License Agreement to Develop and Commercialize NERLYNX® (neratinib) in Europe

Puma Biotechnology, Inc. (Nasdaq: PBYI) and Pierre Fabre have entered
into an exclusive license agreement under which Pierre Fabre will
develop and commercialize NERLYNX® (neratinib) within Europe and part of
Africa. In September 2018 the European Commission granted marketing
authorization for NERLYNX® (neratinib) for the extended adjuvant
treatment of adult patients with early stage hormone receptor positive
HER2-overexpressed/amplified breast cancer and who are less than one
year from the completion of prior adjuvant trastuzumab-based therapy.

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Pierre Fabre will have exclusive commercialization rights for NERLYNX in
European countries excluding Russia and Ukraine, along with countries in
North Africa and francophone countries of West Africa. Pierre Fabre will
also be responsible for conducting additional clinical studies and
leading regulatory activities in connection with the European Medicines
Agency (EMA).

Under the terms of the agreement, Puma will receive an upfront payment
of $60 million, as well as additional regulatory and commercial
milestone payments totaling up to $345 million. In addition, Puma will
receive significant double-digit royalties on NERLYNX sales throughout
the territory covered by the license agreement between Puma and Pierre
Fabre.

“Puma is committed to providing access to NERLYNX to patients around the
world and soon physicians and patients in Europe will have commercial
availability of NERLYNX,” stated Alan H. Auerbach, Chief Executive
Officer and President of Puma. “Pierre Fabre has a robust commercial and
medical oncology infrastructure that we hope will lead to rapid
commercial access to NERLYNX.”

“We are thrilled to provide this new therapy to patients with
HER2-positive breast cancer throughout Europe,” said Frederic Duchesne,
Chief Executive Officer, Pierre Fabre Pharmaceuticals. “Pierre Fabre has
developed a strong expertise and presence in breast cancer treatment and
the addition of NERLYNX to our historical oncology portfolio will allow
us to strengthen our commercial presence. We anticipate providing access
to NERLYNX to patients throughout Europe in 2019 and 2020, starting with
Germany.”

About HER2-Positive Breast Cancer

Approximately 20% to 25% 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.

Important EU NERLYNX® (neratinib) Safety Information

All suspected adverse reactions should be reported in accordance with
the national reporting system.

The adverse reactions described in this section were identified in the
randomized Phase 3 clinical trial (n=2840). The most common adverse
reactions of any grade were diarrhoea (93.6%), nausea (42.5%), fatigue
(27.3%), vomiting (26.8%), abdominal pain (22.7%), rash (15.4%),
decreased appetite (13.7%), abdominal pain upper (13.2%), stomatitis
(11.2%), and muscle spasms (10.0%).

The most common Grade 3-4 adverse reactions were diarrhoea (Grade 3,
36.9% and Grade 4, 0.2%) and vomiting (Grade 3, 3.4% and Grade 4, 0.1%).

Adverse reactions reported as serious included diarrhoea (1.9%),
vomiting (1.3%), dehydration (1.1%), nausea (0.5%), alanine
aminotransferase increased (0.4%), aspartate aminotransferase increased
(0.4%), abdominal pain (0.3%), fatigue (0.3%) and decreased appetite
(0.2%).

For full European prescribing information, please refer to the
NERLYNX (neratinib) Summary of Product Characteristics on the European
Medicines Agency website (http://www.ema.europa.eu/ema/).

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 inpatients
  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. When patients require gastric acid reducing agents, use an
  H2-receptor antagonist or antacid. Separate NERLYNX by at least 3
  hours with antacids. Separate NERLYNX by at least 2 hours before or 10
  hours after H2-receptor antagonists.
• 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 <https://nerlynx.com/pdf/full-prescribing-information.pdf>
for additional safety information.

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. The Company 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 in September 2018 for the
extended adjuvant treatment of adult patients with early stage hormone
receptor-positive HER2-overexpressed/amplified breast cancer and who are
less than one year from completion of prior adjuvant trastuzumab-based
therapy. NERLYNX is a registered trademark of Puma Biotechnology, Inc.

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

About Oncology at Pierre Fabre

Pierre Fabre’s expertise in oncology is based on almost four decades of
experience in the discovery, development and global marketing of
innovative cancer drugs, including monoclonal antibodies and ADCs.
Navelbine® has been one of the company’s major successes and is valuable
in the treatment of breast cancer patients. The company conducts its R&D
in two oncology centers, based in Saint-Julien-en-Genevois (near Geneva)
and at the Oncopole campus in Toulouse. The Oncopole is officially
recognized by the French government as a National Center of Excellence
for cancer research. In 2015, Pierre Fabre entered into an agreement
with the American biotech company, Array BioPharma, to codevelop two
small molecules (kinase inhibitors), Braftovi® & Mektovi®. The primary
indication (melanoma) was approved in September 2018 by EMA and
marketing is already underway in Germany, the UK, the Netherlands,
Austria, Norway and Denmark.

About Pierre Fabre

With a portfolio representing a continuum of activities spanning from
prescription drugs and consumer healthcare products to dermo-cosmetics,
Pierre Fabre is the 2^nd largest dermo-cosmetics laboratory in
the world, the 2^nd largest private French
pharmaceutical group and the market leader in France for products sold
over the counter in pharmacies. Its portfolio includes several global
brands and franchises among which Eau Thermale Avène, Klorane, Ducray,
René Furterer, A-Derma, Galénic, Elancyl, Naturactive, Pierre Fabre
Health Care, Pierre Fabre Oral Care, Pierre Fabre Dermatologie and
Pierre Fabre Oncologie.

In 2018, Pierre Fabre generated 2.3 billion euros in revenues, of which
63% came from its international business and 61% from its
dermo-cosmetics division. Pierre Fabre, which has always been
headquartered in the South-West of France, counts about 11,000 employees
worldwide, owns subsidiaries and offices in 47 countries and enjoys
distribution agreements in over 130 countries. In 2018, Pierre Fabre
dedicated 187 million euros to R&D efforts, split between oncology,
consumer healthcare, dermatology and dermo-cosmetics.

Pierre Fabre is 86%-owned by the Pierre Fabre Foundation, a
government-recognized public-interest foundation, and secondarily by its
own employees through an international employee stock ownership plan.

The independent French certification group AFNOR audited in 2015 Pierre
Fabre for its corporate social responsibility policy at the “exemplary”
level, according to the ISO 26000 standard for CSR.

To find out more about Pierre Fabre, please go to www.pierre-fabre.com.

Forward-Looking Statements

This press release contains forward-looking statements, including
statements regarding the commercialization and commercial availability
of NERLYNX^® in European countries excluding Russia and
Ukraine, along with countries in North Africa and francophone countries
of West Africa; the registration and regulatory approval of NERLYNX in
the region; and potential payments and royalties payable under the
license agreement.. 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.

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