Puma Biotechnology has announced that the US Food and Drug Administration (FDA) has approved Nerlynx (neratinib), formerly known as PB272, a once-daily oral tyrosine kinase inhibitor for the extended adjuvant treatment of adult patients with early stage HER2-overexpressed/amplified breast cancer, following adjuvant trastuzumab-based therapy. Puma expects neratinib to become commercially available in September 2017 and to be marketed as Nerlynx.

FDA 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.

"The fear of recurrence is ever present in the minds of most women with breast cancer, from the moment they are diagnosed to long after they finish adjuvant treatment," said Marisa C. Weiss, M.D., chief medical officer and Founder of Breastcancer.org. “New and effective innovative therapeutic options provide huge hope to patients and their families, giving them a better chance of overcoming breast cancer with a chance for a full life.”

“Despite advances in the treatment of early stage HER2-positive breast cancer, there remains a need for further therapeutic improvements in order to attempt to further reduce the risk of disease recurrence,” said Puma Biotechnology CEO and President Alan H. Auerbach. “We are pleased to be able to bring this new medicine to patients with breast cancer. We 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.”

Nerlynx is a tyrosine kinase inhibitor indicated for the extended adjuvant treatment of adult patients with early stage HER2-overexpressed/amplified breast cancer, to follow adjuvant trastuzumab-based therapy.