US-based biopharmaceutical company Puma Biotechnology has reported interim five-year disease-free survival data from the Phase III ExteNET trial of PB272 (neratinib) for an adjuvant treatment of early stage, HER2-positive breast cancer.
Puma’s investigational drug PB272 acts as an irreversible tyrosine kinase inhibitor, blocking signal transduction through the epidermal growth factor receptors HER1, HER2 and HER4.
The ExteNET trial involved 2,840 patients with early stage, HER2-positive breast cancer who had undergone surgery and adjuvant treatment with trastuzumab.
After being treated with trastuzumab, patients were randomised to be administered with an extended adjuvant treatment with either neratinib or placebo for one year.
The trial was primarily focused to determine the invasive disease free survival (DFS) post treatment with neratinib.
An interim five-year invasive DFS analysis has displayed a 26% reduction of risk of invasive disease recurrence or death as compared to placebo.
Puma president and CEO Alan Auerbach said: “We believe these results support the long-term clinical benefit of neratinib in the extended adjuvant treatment of patients with early stage HER2-positive breast cancer who have completed prior trastuzumab-based adjuvant therapy.
“We look forward to obtaining the full five-year DFS data, which we anticipate will be available in 2017.”
A previous two-year DFS rate for the neratinib arm of the trial was determined at 93.9% compared to placebo at 91.6%.