Treatment of HER2+/HR+early breast cancer with neratinib: final results from a retrospective single case report retrieval project

Purpose: Neratinib is an oral, irreversible pan-HER tyrosine kinase inhibitor approved in Europe as extended adjuvant treatment for adult patients with HER2+/HR+early breast cancer (eBC) who completed adjuvant trastuzumab-based therapy<1 year ago. In the phase III ExteNET study, neratinib significantly improved 5-year invasive disease-free survival (Δ5.1%, HR 0.58, 95%CI 0.41-0.82).

This retrospective single case report project aims to collect real-world data on treatment management of patients with HER2+/HR+eBC who received extended adjuvant neratinib in different treatment scenarios.

Material and Methods: Single case reports of adult patients with HER2+/HR+eBC treated with neratinib for≥3 months were selected based on the following treatment scenarios by participating sites in Germany and Austria:

I: adjuvant trastuzumab (T)

II: adjuvant trastuzumab+pertuzumab (T+P)

IIIa: pathological complete response (pCR) after neoadjuvant T+P, post-neoadjuvant T

IIIb: pCR after neoadjuvant T+P, post-neoadjuvant T+P

IV: non-pCR after neoadjuvant T+P, post-neoadjuvant T-emtansine (T-DM1)

Results: Twenty-seven case reports were documented at 8 sites (first-patient-in: 21-Aug-2023, last-patient-in: 27-Jan-2025). Representative patient cases will be presented including patient, disease and treatment characteristics as well as neratinib safety profile.

Conclusions: Patient cases collected within this project provide interesting insights on treatment situations of patients with HER2+/HR+eBC treated with (neo)adjuvant anti-HER2 therapy and extended adjuvant neratinib in Germany and Austria. These data could serve as a basis for clinical practice discussions in the management of HER2+/HR+eBC.

Funded by Pierre Fabre Pharma.

Publication History

Article published online:
04 June 2025