18 July 2019 - - US-based Puma biotechnology, Inc. (NASDAQ: PBYI) licensing partner Knight Therapeutics Inc. (Knight) has received marketing authorisation from Health Canada to commercialise Nerlynx (neratinib) in Canada for the extended adjuvant treatment of women with early stage hormone receptor positive, HER2-overexpressed/amplified breast cancer within one year after completion of trastuzumab-based adjuvant therapy, the company said.
Health Canada approval was based on the Phase III ExteNET trial, a multicenter, randomised, 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 therapy 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, for patients with hormone receptor positive, HER2-positive early stage breast cancer patients who were treated within one year after the completion of trastuzumab based adjuvant therapy, invasive disease-free survival was 95.3% in the patients treated with neratinib compared with 90.8% in those receiving placebo (hazard ratio = 0.49; 95% CI: (0.30, 0.78); p=0.002).
The most common adverse reactions 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.
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.
Puma biotechnology is a biopharmaceutical company with a focus on the development and commercialisation 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 US 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.