U.S. Food and Drug Administration Approval: Neratinib for the Extended Adjuvant Treatment of Early Stage HER2-Positive Breast Cancer
Cet article analyse les éléments d'un essai clinique utilisés par la FDA pour approuver l'utilisation du nératinib en traitement adjuvant étendu chez des patientes atteintes d'un cancer du sein HER2+ de stade préoce, après un traitement adjuvant à base de trastuzumab, et évalue son efficacité, du point de vue de la survie sans maladie, et sa toxicité
On July 17, 2017, the Food and Drug Administration (FDA) approved neratinib (NERLYNX, Puma Biotechnology, Inc) for the extended adjuvant treatment of adult patients with early-stage HER2-overexpressed/amplified breast cancer, to follow adjuvant trastuzumab-based therapy. Approval was based on data from ExteNET, a randomized, double-blind, placebo-controlled multicenter trial. Women with early-stage HER2-positive breast cancer and within two years of completing adjuvant trastuzumab were randomized to neratinib (n=1420) or placebo (n=1420) for one year. The primary endpoint was invasive disease-free survival (iDFS) defined as the time between randomization date to first occurrence of invasive recurrence (local/regional, ipsilateral or contralateral breast cancer), distance recurrence, or death from any cause, with two years and 28 days of follow up. The trial showed a statistically significant treatment effect favoring neratinib with a stratified hazard ratio of 0.66 (95% CI: 0.49, 0.90, p=0.008). Estimated iDFS rate at 2-years was 94.2% (95% CI: 92.6%, 95.4%) in patients treated with neratinib vs. 91.9% (95% CI: 90.2%, 93.2%) in those receiving placebo. Diarrhea was the most common adverse event (AE) with a 40% incidence of Grade 3 or 4 diarrhea and represents the most common AE leading to treatment discontinuation. Other frequent AEs (>10% incidence) were nausea, abdominal pain, fatigue, vomiting, rash, stomatitis, decreased appetite, and muscle spasms. Other than diarrhea, neratinib is associated with a low incidence of severe AEs; toxicities are generally reversible and manageable with dose interruptions, dose reductions, and/or standard medical care. This article summarizes FDA decision-making and data supporting the neratinib approval.