Gavreto (pralsetinib) is a targeted therapy for advanced or metastatic non-small cell lung cancer (NSCLC) and thyroid cancers with RET gene changes (mutations). Gavreto (pralsetinib) is a recommended option for those cancers, and it’s conveniently available as pills you take by mouth once a day. But it often causes troublesome fatigue, constipation, and high blood pressure.
Some cancers form when normal cells in the body have changes (mutations) in their genetic material. These mutations can lead to abnormal proteins, which causes the tumors to grow and spread.
Specifically, certain cancers have changes in the RET gene. These changes can result in abnormal RET proteins that send signals for tumors to grow. Gavreto (pralsetinib) interrupts tumor growth by blocking these abnormal RET proteins from sending the growth signal.
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.
Please note: Side effect information is from studies of people taking Gavreto (pralsetinib) alone for thyroid cancer.
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):
Gavreto (pralsetinib) is a targeted therapy that works against certain lung or thyroid cancers that have changes (mutations) in the RET gene. Your provider will take a blood or tissue sample (biopsy) to test if you have changes in RET. If the tests show RET gene changes, Gavreto (pralsetinib) might be an option for you.
Usually, you’ll keep taking Gavreto (pralsetinib) for as long as it continues working against your cancer. To make sure the medication’s still working, your provider will check in on your symptoms at each visit and do scans every few months. If your provider sees signs of your cancer spreading on the scans, or if you’re having more symptoms from your cancer, you might need to stop Gavreto (pralsetinib) and adjust your treatment plan with your provider. In addition, your provider might decide to stop Gavreto (pralsetinib) treatment if you’re having trouble with side effects. Let your provider know if side effects like pain, tiredness, or constipation bother you. They’ll evaluate your symptoms and check your blood tests for signs of side effects you might not feel. Depending on how severe your side effects are, your provider might have you take a short break from the medication and restart at a lower dose, or make other changes to your treatment plan.
Constipation is a common of Gavreto (pralsetinib). Most of the time, it’s mild. Your provider can recommend ways to help you manage constipation through ways such as drinking enough water to stay well-hydrated, engaging in regular exercise, and eating fiber-rich foods. If constipation is bothering you, you can also ask your provider about constipation medications to help manage your symptoms.
Gavreto (pralsetinib) can cause high blood pressure. In studies, people with high blood pressure were able to continue taking Gavreto (pralsetinib) by using blood pressure lowering medications. To prevent high blood pressure, you can make sure to stay physically active and maintain a low-salt diet. Your provider will also check on your blood pressure to make sure it’s within a safe range, and they might have you start blood pressure-lowering medications if your blood pressure goes above the safe range.
No. Gavreto (pralsetinib) isn’t safe for people who are pregnant because it can cause harm to the unborn baby. If you’re able to become pregnant, use an effective barrier method (e.g. condoms) while taking Gavreto (pralsetinib) and for 2 weeks after stopping.
Gavreto (pralsetinib) 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.
Gavreto (pralsetinib) can cause damage to the lungs. In rare cases, this can be life-threatening. Let your healthcare team know if you have a new or worsening cough, trouble catching your breath, or fevers. You’ll probably need to stop the medication while your provider checks your lungs for problems.
Let your provider know if have high blood pressure. If your blood pressure isn't under control, you won't be able to start Gavreto (pralsetinib) because this medication can also cause high blood pressure. Your provider will check your blood pressure before you start Gavreto (pralsetinib) and regularly while you’re receiving treatment. If needed, they’ll prescribe you blood pressure lowering medications. If your blood pressure isn’t well-controlled by medications, your provider might have you temporarily take a break from Gavreto (pralsetinib) while working on getting your blood pressure back down to a safe range. Once your blood pressure is back to a safe range, they’ll have you start Gavreto (pralsetinib) again, but at a lower dose. In rare cases, if your blood pressure is still dangerously high even with blood pressure medication, your provider might have you stop taking Gavreto (pralsetinib). If you notice symptoms of dangerously high blood pressure like dizziness or headache, let your provider know.
Gavreto (pralsetinib) might damage your liver. Let your healthcare team know if you notice signs of liver damage, such as pain in the right side of the stomach, yellowing of the eyes or skin, or dark or brown urine. But many people don’t feel any physical symptoms from liver problems. Your provider will order blood tests regularly to track how well your liver is working (every 2 weeks for the first 3 months, then monthly afterward). In studies, some people had higher levels of liver enzymes on their blood tests (a sign of potential liver injury) within the first 3 weeks of starting Gavreto (pralsetinib). If your provider suspects that you have liver damage, your provider might have you take a break from Gavreto (pralsetinib). Once your liver test results return to normal, you might be able to restart the medication at a lower dose.
In rare cases, Gavreto (pralsetinib) contributed to serious bleeding, which could be fatal. Bleeding can happen anywhere in the body, including in the lungs, stomach, and brain.
If you experience any serious or unusual bleeding, especially bleeding that’s hard to stop, seek medical attention immediately. Get medical help right away if you feel nauseous, have a sudden or painful headache, notice a change in your vision, have stomach pain, or are coughing or spitting up blood.
Gavreto (pralsetinib) can slow down the wound healing process. If you're going to have surgery or any other procedures, let your provider know. They’ll ask you to stop taking this medication at least 5 days before a planned surgery. After major surgery, you should wait for at least 2 weeks before starting this medication again, checking with your healthcare team to make sure your wound is fully healed before restarting treatment. If you have an injury and notice the wound’s taking a long time to heal, make sure to tell your care team.
Risk factors: Rapidly growing tumors | Large amount of tumor in the body | History of kidney problems | Dehydration
In clinical studies, a few people taking Gavreto (pralsetinib) for thyroid cancer experienced a serious reaction called tumor lysis syndrome (TLS). TLS happens when many cancer cells die and suddenly break down in your body, all at the same time. When this happens, the cells release their inner contents, like uric acid, potassium, and phosphorus, into your blood. High levels of uric acid and electrolytes in your body can cause serious problems, such as kidney damage and abnormal heart rhythms.
When you start treatment with Gavreto (pralsetinib), your provider will order labs for you to check for signs of TLS. Tell your provider right away if you’re having signs of TLS, such as urinating less than usual or having dark urine, muscle cramps, or a racing heartbeat. To prevent TLS, it’s a good idea to drink enough fluids daily to keep hydrated. If needed, your provider might give you intravenous (IV) fluids and prescribe you medications to lower your uric acid levels.
Let your provider know if you are pregnant or plan to become pregnant. Gavreto (pralsetinib) might affect fertility and is likely to harm unborn babies. If you’re able to become pregnant, your provider will have you do a pregnancy test before starting treatment. They’ll also ask you to use effective non-hormonal birth control while taking this medication and for at least 2 weeks after your last dose. If you’re male and have a partner who’s able to become pregnant, continue using effective birth control while taking Gavreto (pralsetinib) and for at least a week after the last dose.
The typical dose is 400 mg by mouth daily on an empty stomach.