What is Nerlynx® (neratinib)?

Reviewed by: HU Medical Review Board | Last reviewed: June 2023

Nerlynx is a targeted therapy that is approved for use in early-stage breast cancer that is positive for human epidermal growth factor receptor 2 (HER2+) after treatment with trastuzumab to reduce the risk of the cancer coming back (recurrence).1

Neratinib is also used in combination with capecitabine to treat certain people with advanced or metastatic HER2+ breast cancer that have previously been treated with at least 2 treatments for metastatic breast cancer that target HER2.2,3

What are the ingredients in Nerlynx?

The active ingredient in Nerlynx is neratinib.1

How does neratinib work?

Some breast cancers have an excess of the human epidermal growth factor receptor 2 (HER2). These are classified as HER2-positive breast cancers (HER2+). Breast cancers that have too many HER2 receptors can grow and spread quickly. Blocking these receptors can slow or stop the growth of these cancers. Neratinib binds to HER2 receptors to slow or stop breast cancer.1

What are the possible side effects of neratinib?

The most common side effects of neratinib when used alone include:1,4

  • Diarrhea
  • Nausea, vomiting
  • Fatigue
  • Rash
  • Upset stomach, abdominal pain
  • Decreased appetite
  • Mouth sores
  • Muscle spasms
  • Changes to the nails
  • Dry skin
  • Weight loss
  • Urinary tract infection
  • Nose bleed

Neratinib may cause serious side effects, including:1,4

  • Severe diarrhea – This may lead to dehydration. Anti-diarrheals may be started with neratinib (follow your doctor’s instructions regarding any anti-diarrheal medications prescribed). Contact your doctor if you have severe diarrhea or diarrhea along with weakness, dizziness, or fever.
  • Liver problems – Your doctor should monitor your liver function before and during treatment with neratinib. Contact your doctor if you have signs of liver problems, such as nausea, vomiting, abdominal pain, fever, rash, itching, or yellowing of the skin or eyes (jaundice).

These are not all the possible side effects of neratinib. Talk to your doctor about what to expect with treatment or if you experience any changes that concern you during treatment with neratinib.

Things to know about neratinib

Avoid eating or drinking grapefruit products while taking neratinib. Grapefruit products may increase the levels of neratinib in the body. This can increase the chance of side effects.1,4

Before starting treatment with neratinib, tell your doctor if you have liver problems.1,4

Neratinib can harm an unborn baby. If you or your partner can become pregnant, you should use birth control during treatment and for some time after the last dose of neratinib.  You should also not breastfeed during treatment with neratinib and for some time after the last dose. Talk to your doctor about your options for birth control and breastfeeding while taking neratinib.1,4

Before beginning treatment for breast cancer, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you are taking. This includes over-the-counter drugs.

For more information, read the full prescribing information of neratinib.

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