309P - A multicenter, prospective, non-interventional study to investigate the treatment patterns of neratinib in human epidermal growth factor receptor 2 positive (HER2+) early breast cancer (EBC) in China: Interim analysis of the NER-Tree study

Background

Neratinib, an oral irreversible pan-HER tyrosine kinase inhibitor, was approved in 2020 in China. However, with the evolving treatment practices for HER2+ EBC in China, like the increased use of pertuzumab, understanding real-world extended adjuvant neratinib use in China is crucial.

Methods

This is a multi-center, prospective, non-interventional study planning to enroll 500 HER2+ EBC patients who scheduled extended adjuvant neratinib treatment. The primary and secondary objectives are to describe the real-world adjuvant treatment patterns and to observe the safety of patients treated with neratinib respectively.

Results

As of 21 September 2023, 250 patients were included in the analysis. 90.5% in the neoadjuvant therapy and 88% in the adjuvant therapy received pertuzumab plus trastuzumab. The median time from completion of previous adjuvant therapy until the start of neratinib treatment was 1.3 months (interquartile range: 0.69-3.38). The initial dose of neratinib was <240 mg for 51.2% and 240 mg for 48.8% of the patients. 59.6% received diarrhea prophylaxis at least once, including prophylaxis medication (33.2%), dose-escalated (17.2%), or both (9.2%). Serious adverse events (SAEs) and Grade ≥3 adverse events (AEs) were reported in 3.6% and 18.8% of the patients respectively. The most common AEs of any grade were diarrhea (79.6%), nausea (20.4%), and fatigue (14.8%). Diarrhea was predominantly reported as Grade 1 or 2 (64.8%), while Grade ≥3 diarrhea was reported in 14.8% of the patients. The incidence of Grade ≥3 diarrhea was lower in the patients starting neratinib at <240 mg (10.2%) as compared with 240 mg (19.7%).

Conclusions

The profile of patients and pattern of anti-HER2 pretreatment reflected the current disease and treatment landscape for HER2+ EBC in China. The overall safety profile was consistent with previously reported data. With cross-trial comparison, the proportion of patients with Grade ≥3 diarrhea was lower if indirectly compared to the ExteNET study (14.8% vs. 40%), which may reflect increasing awareness of the risk of diarrhea and increasing use of the antidiarrheal strategies.

Clinical trial identification

NCT05491057.

Editorial acknowledgement

Legal entity responsible for the study

Pierre Fabre.

Funding

This study is sponsored by Pierre Fabre.

Disclosure

All authors have declared no conflicts of interest.