Observational Study on Side Effects (Primarily Diarrhea) Associated with Treatment with Neratinib (Medication)

Breast cancer is a malignant disease of the breast that primarily affects women. Breast cancer occurs in various forms, so there is no single clinical picture. This also means that treatment varies depending on the extent of the disease (stages 1–4) or specific characteristics of the cancer cells, such as hormone receptors or the HER2 receptor. In general, breast cancer treatment can lead to side effects that may require additional doctor’s visits or a change in treatment. While the occurrence of side effects varies from person to person, certain medications have typical side effects that may occur more frequently. The standard treatment for early-stage HER2-positive breast cancer consists of an initial course of chemotherapy (“neoadjuvant”) followed by surgical removal of the tumor. This is often followed by further therapy (“adjuvant”). Tyrosine kinase inhibitors (TKIs), among other treatments, are used to reduce the risk of recurrence. One such medication is neratinib. Previous studies have shown that diarrhea occurs more frequently when taking neratinib.

The goal of the NERLYFE study is to observe how often patients must interrupt or discontinue therapy with neratinib due to diarrhea. To this end, patients receiving the treatment will be examined at the clinic once a month during the first three months after the start of treatment and asked about their well-being. Thereafter, examinations will take place every six months for up to two years after the start of treatment. The study is purely observational and does not prescribe any treatment plans.

Women and men over the age of 18 with early-stage (Stage 1–2) HER2-positive breast cancer who are receiving adjuvant therapy with the tyrosine kinase inhibitor (TKI) neratinib are eligible to participate in the study.