Tukysa (tucatinib) is an oral medication that treats advanced or metastatic HER2-positive breast cancer. Tukysa (tucatinib) is used with other medications to treat your breast cancer. It’s a tablet that’s taken by mouth, but often causes diarrhea, which can be bothersome.
Tukysa (tucatinib) is a tyrosine kinase inhibitor. It works by blocking the action of a protein called human epidermal growth factor receptor 2 (HER2). This protein is found on both normal and cancer cells. But in HER2-positive breast cancer, the cancer cells typically have more HER2 proteins than normal cells. When this protein is blocked by Tukysa (tucatinib), cancer cells can’t grow and spread as well.
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
When used with other anticancer medications:
Contact your healthcare provider immediately if you experience any of the following.
Side effects that you should report to your care team as soon as possible:
Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome):
Your care team will talk with you about how long you’ll need to take Tukysa (tucatinib). In general, you’ll continue to take Tukysa (tucatinib) as long as your cancer doesn’t get worse. But if your cancer progresses, if you experience certain side effects like diarrhea, or if your provider finds that the medication is causing liver damage, your care team will discuss with you about what this means and if you need to pause or stop treatment. Don’t stop taking Tukysa (tucatinib) without talking with your healthcare provider first.
If you forget to take Tukysa (tucatinib) or vomit after taking the medication, don’t take another dose of Tukysa (tucatinib) to try to make up for it. Just wait and take the medication at your next usually scheduled time. For example, if you typically take Tukysa (tucatinib) at 8:00 AM and 8:00 PM every day, and you forget to take the medication in the morning, skip the missed dose and wait to take your evening dose. Continue with how you usually take the medication the next day.
No. Chemotherapy is a term used for cancer medications that kill cancer cells in your body. Unlike traditional chemotherapy, Tukysa (tucatinib) slows cancer cell growth. As part of treatment, Tukysa (tucatinib) is taken together with a chemotherapy medication called capecitabine (Xeloda).
No. Even though there are many different types of breast cancer, Tukysa (tucatinib) treats advanced or metastatic HER2-positive breast cancer. To figure out the receptor type of your cancer, your provider will perform a biopsy or surgery to remove a small piece of your breast tissue. Knowing what type of receptor your cancer has will help your provider decide what treatment plans to consider and discuss with you. Tukysa (tucatinib) is specifically used for people who’ve already tried at least one other treatment plan that targets HER2, such as those with Herceptin (trastuzumab) or Perjeta (pertuzumab).
It isn’t recommended to breastfeed while receiving Tukysa (tucatinib). It’s not known if the medication can get into breast milk, but there’s a risk of serious harm to nursing infants if it does. Because of this risk, don’t breastfeed during Tukysa (tucatinib) treatment and for 1 week after your last dose. Discuss with your provider if you have any questions about breastfeeding or other ways to feed your baby while taking Tukysa (tucatinib).
Tukysa (tucatinib) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Tukysa (tucatinib) can cause diarrhea. Though less common, severe cases can lead to complications like dehydration, low blood pressure, and even death. In studies, diarrhea typically happened within the first 2 weeks of starting Tukysa (tucatinib) and lasted about 8 days. If you begin to experience diarrhea or any changes in your bowel movements, let your provider know immediately. They can recommend you to take an antidiarrheal medication like loperamide (Imodium A-D). Your provider might also lower your dose, pause treatment until your diarrhea gets better, or in severe cases, have you stop taking Tukysa (tucatinib).
Tukysa (tucatinib) can sometimes cause severe liver damage. Because of this risk, your provider will check your liver health through lab work while you’re taking this medication. Let your provider know if you develop any symptoms of liver problems, such as itchy skin, yellowing of skin or whites of your eyes, dark-colored urine, and pain or discomfort in the right upper stomach area. Your provider might lower your dose, pause treatment temporarily, or have you stop taking Tukysa (tucatinib).
Tukysa (tucatinib) might cause harm to an unborn baby. If you're a female who can get pregnant and you’re taking Tukysa (tucatinib), your provider might check to make sure you’re not pregnant before you start treatment. You’ll also need to use birth control during treatment and for at least 1 week after your last dose. If you’re a male taking Tukysa (tucatinib) and your partner is able to become pregnant, you should use birth control during treatment and for at least 1 week after your last dose as well. Let your provider know right away if you or your partner becomes pregnant during this time.
The typical dose is 300 mg taken orally twice a day (about 12 hours apart).
Your dose might be different if you have severe liver problems or if you're also taking certain medications (see Pharmacist Tips for more information).