Nerlynx can cause diarrhoea when therapy is commenced. Diarrhoea may be severe, causing dehydration, unless loperamide is introduced to prevent or reduce this side effect. Patients are advised to speak to their clinicians if they can’t take loperamide and to start taking loperamide with the first dose. Professor Arlene Chan discusses this side effect and optimal management.

The ExteNET study was a randomised, double-blind, placebo-controlled Phase 3 investigation examining the efficacy and safety of 12 months of NERLYNX (neratinib) after trastuzumab-based adjuvant therapy in patients with early-stage HER2-positive breast cancer. Eligible women (aged ≥18 years, or ≥20 years in Japan) had stage 1–3 HER2-positive breast cancer and had completed neoadjuvant and adjuvant trastuzumab therapy up to 2 years before randomisation. Inclusion criteria were amended in February 2010 to include patients with stage 2–3 HER2-positive breast cancer who had completed trastuzumab therapy up to 1 year previously. Patients were randomly assigned (1:1) to receive oral neratinib 240 mg per day or matching placebo. The study met its primary endpoint.

HER2+ breast cancer is typically regarded as an aggressive form of the disease. In this piece, international breast cancer authority Professor Arlene Chan AM discusses the ongoing risk of disease recurrence for HER2+ patients following chemotherapy and trastuzumab-based therapy.