Neratinib, also known as, Nerlynx is a tyrosine-kinase inhibitor. Tyrosine-kinase inhibitors target tyrosine-kinase enzymes, which are important for cell functions. They can block tyrosine-kinase enzymes at many points along the cancer growth pathway.

Neratinib is used to treat HER2-positive early breast cancer in some women who have completed treatment with trastuzumab, or Herceptin. Treatment with neratinib may reduce the risk of breast cancer recurrence in some people.

Neratinib is a pill taken every day for one year.

The most common side effect of neratinib is diarrhea. Your health care provider will recommend medications to help control the diarrhea.

Other side effects include nausea, abdominal pain, fatigue, vomiting and rash. More serious health risks include liver damage.

Neratinib is also used to treat HER2-positive metastatic breast cancer. For more information, see the Living with Metastatic Breast Cancer section in this tool.