Neratinib was approved as an extended adjuvant therapy by FDA in 2017 for patients (pts) with HER2+ eBC and by the EMA in 2018 for pts with HER2+ HR+ eBC who completed adjuvant trastuzumab-based therapy within the prior 1 year (EU Label) based on the phase III ExteNET trial. The present study objective was to investigate neratinib effectiveness and tolerability in real-world clinical practice.
Patients with stage I–III HER2+ eBC who started extended adjuvant neratinib at US Oncology Network centres from 15 July 2017 to 30 June 2020 were retrospectively identified and followed to last visit, death or study end. Demographic/clinical data, effectiveness and tolerability outcomes were extracted from electronic medical records and assessed descriptively.
Of 240 patients, 166 pts (69.2%) had HER2+ / HR+ eBC and had completed adjuvant trastuzumab-based treatment within 1 year of initiating extended adjuvant neratinib (EU Label). The median age was 50 years. 72% (n=120) of patients presented stage ≥ II. 106 pts received neoadjuvant therapy (96.2% pertuzumab) and of those, 49 patients (46.2%) achieved a pathological complete response (pCR). 72 (43.4%) and 3 (1.8%) pts received prior adjuvant pertuzumab or T-DM1, respectively. 81.3% initiated neratinib at full dose and 12.6% had dose escalation. 38% of patients required dose adjustments since treatment start. Median neratinib treatment duration was 11.6 months. Six pts had invasive relapses (5 distant, 1 locoregional) over a median of 26.9 months of follow-up. The 12- and 24-month iDFS rates were 97.5% and 96.0%, respectively. 90.4% of patients experienced any-grade diarrhea during treatment, which was the main AE leading to treatment discontinuation. Patients who received anti-diarrheal prophylaxis (66.9%) had a longer median time to discontinuation than patients who did not receive prophylaxis (11.8 and 6.8 mo, respectively).
Based on these US community oncology data, the real-world effectiveness of neratinib in patients with HER2+ HR+ eBC ≤ 1 year after completing current adjuvant trastuzumab based therapies is consistent with that observed in the ExteNET study with no new safety findings.
Catherine Rees provided editorial assistance in the development of this abstract on behalf of Springer Healthcare Communications. This medical writing assistance was funded by Pierre Fabre.
Pierre Fabre Medicament.
Pierre Fabre.
D.I. Lüftner: Financial Interests, Personal, Invited Speaker: Roche, Pierre Fabre, Daiichi Sankyo, Gilead; Financial Interests, Personal, Advisory Role: Roche, Pierre Fabre, Daiichi Sankyo, Gilead. J. O'Shaughnessy: Financial Interests, Advisory Role: AbbVie Inc., Agendia, Aptitude Health, AstraZeneca, Athenex, Bayer, Bristol Myers Squibb, Caris, Carrick Therapeutics, Celgene Corporation, Daiichi Sankyo , Eisai, Exact Sciences, G1 Therapeutics , Genentech, Gilead Sciences, Immunomedics, Lilly, Merck, Novartis, Ontada, Pfizer, Pharmacyclics, Pierre Fabre Pharmaceuticals, Puma Biotechnology, Prime Oncology, Roche, Samsung Bioepis, Sanofi, Seagen, Theralink, Synthon. A. Zkik, O. Dialla, M. Brignone, M. Zivanov: Financial Interests, Personal, Full or part-time Employment: Pierre Fabre. J. Andersen: Financial Interests, Personal, Speaker’s Bureau: Puma, AstraZeneca, DSI, Exact Sciences, Gilead, Seagen; Financial Interests, Personal, Advisory Board: AstraZeneca, Athenex, Novartis, Merck, Biotheranostics.