Reviewed by: HU Medical Review Board | Last updated: July 2022
RetevmoTM (selpercatinib) is a targeted therapy that is used to treat some adults with metastatic (has spread to other parts of the body) non-small cell lung cancer (NSCLC) that is positive for certain changes in a gene known as rearranged during transfection (RET). It was the first therapy approved for adults with NSCLC specifically driven by changes in the RET gene. Selpercatinib may also be used to treat patients with certain forms of thyroid cancer.1
The FDA based its accelerated approval on a Phase 1/2 trial showing cancer response to the treatment, as well as the duration of the response that was shown. Continued approval of selpercatinib may depend on the results of more clinical trials to confirm the benefit of the medication.2
Selpercatinib should only be used by people with NSCLC who have certain changes in the RET gene. Your doctor can determine if it is right for you through biomarker testing. Talk to your doctor about getting tested for all treatable cancer biomarkers.
How does selpercatinib work?
Selpercatinib blocks a protein called “rearranged during transfection” (RET). Normally, RET is a healthy protein that is automatically switched on or off depending on the body’s needs. But sometimes, accidental rearrangements in our DNA cause changes to the RET gene. The changes in the RET gene can result in the RET protein being switched on continuously, and can lead to uncontrolled cancer cell growth.3
You can imagine the normal RET protein like a dam that manages water flow. If the dam breaks, uncontrolled water flow may cause flooding. Similarly, uncontrolled cell growth caused by the alterations in the RET gene can lead to cancer.
RET gene changes are present in about 2 percent of NSCLC cases. Selpercatinib blocks the overactive protein and prevents tumor growth. However, it can also affect healthy cells and cause side effects.3,4
What are the possible side effects of selpercatinib?
Selpercatinib may cause serious side effects, as some were noted during clinical trials. The most common serious side effect experienced was pneumonia. Tell your doctor right away if you experience any symptoms for each side effect listed below. Your doctor may temporarily stop treatment, lower your dose, or permanently stop treatment.4
Liver problems are common with selpercatinib and may sometimes be serious. Your doctor will check for liver problems by doing blood tests before and during treatment. Tell your doctor if you have any symptoms of liver problems, including:5
- Yellow skin or eyes
- Dark urine
- Loss of appetite
- Nausea or vomiting
- Pain on upper right side of stomach
High blood pressure
High blood pressure (hypertension) may also happen and can be serious. Check your blood pressure regularly during treatment. Tell your doctor if you experience confusion, headaches, shortness of breath, dizziness, or chest pain.5
Heart rhythm changes
Selpercatinib can cause very slow, very fast, or irregular heartbeats. Tell your doctor if you experience loss of consciousness, fainting, dizziness, or heart palpitations.5
Selpercatinib may cause bleeding, which can sometimes be very serious. Tell your doctor if you have any signs of bleeding during treatment:5
- Vomiting or coughing up blood
- Unusual urine or stool color
- Unusual bleeding or bruising of skin
- Frequent nosebleeds
- Changes in speech
Selpercatinib may cause a fever, rash, or muscle or joint pain. This usually happens in the first month of treatment. Tell your doctor if you experience some, or all, of these symptoms.5
Risk of wound healing problems
Selpercatinib may prevent wounds from healing properly. Tell your doctor if you plan to have surgery before or during treatment. Your doctor should instruct you on any potential adjustments to your treatment regimen prior to the procedure.5
Other side effects
If you are pregnant, plan to become pregnant, or are breastfeeding or plan to breastfeed, talk with your doctor. Selpercatinib can cause harm to a developing fetus and should not be taken by women who are pregnant. While taking selpercatinib, males with female partners who can become pregnant, and females who can become pregnant, should both use contraceptives during treatment and for a period of time after completing treatment (patients should discuss appropriate birth control methods, and how long they need to use them, with their doctor). Females should not breastfeed during selpercatinib treatment and for a period of time following the final dose (patients should discuss breastfeeding considerations with their doctor).4
These are not all the possible side effects of selpercatinib. Talk to your doctor to find out what to expect during treatment.
Things to know about selpercatinib
Selpercatinib should be taken exactly as prescribed. The dosage depends on your body weight and medical history. Tell your doctor about any medical conditions you have, such as liver problems, high blood pressure, heart problems, or bleeding problems.4,5
Before beginning treatment with selpercatinib, patients should talk to their doctor about all medications (prescription and over-the-counter), vitamins, and supplements they are taking. Some medications or supplements may interfere with each other or cause unsafe side effects. Patients should take their medication as prescribed by their doctor. Patients should talk to their doctor if they have any questions, or if they have questions regarding their selpercatinib regimen.4,5