Neratinib Maleate is primarily used in the treatment of early-stage HER2-positive breast cancer. It is often prescribed as an extended adjuvant therapy after initial treatment with trastuzumab, helping to reduce the risk of cancer recurrence. This medication works by inhibiting multiple HER receptors, which play a critical role in the growth and survival of cancer cells. It is also being investigated for use in advanced or metastatic HER2-positive breast cancer, as well as other HER2-driven cancers, such as gastric and colorectal cancers. Patients typically take it orally, and it may be combined with other therapies for enhanced efficacy. Common side effects include diarrhea, nausea, and fatigue, which are managed with supportive care.