Venclexta (venetoclax) is a first-choice medication that treats certain cancers of the blood or lymph nodes, like acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), and small lymphocytic lymphoma (SLL). You typically take it by mouth once daily, either on its own or in combination with other chemotherapy or targeted medications, depending on your condition. Venclexta (venetoclax) can put you at risk for a serious side effect called tumor lysis syndrome (TLS).
Venclexta (venetoclax) is a type of targeted therapy called a BCL-2 inhibitor. BCL-2 is a protein that helps cancer cells survive. Certain cancers, like AML and CLL/SLL, have too many BCL-2 proteins. This allows them to continue growing uncontrollably. Venclexta (venetoclax) works by targeting and blocking BCL-2 on cancer cells, which allows it to kill and slow down the growth of cancer cells.
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: These side effects were reported by people who took only Venclexta (venetoclax). The side effects you experience might differ if you're taking Venclexta (venetoclax) 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 to your care team if they continue or are bothersome):
No, Venclexta (venetoclax) is not a chemotherapy medication. It’s a type of targeted anticancer therapy. Chemotherapy is a class of medication that kills cells that multiply quickly in your body, like cancer cells. But it can also end up killing some healthy cells as well. Venclexta (venetoclax) is more precise in the way it targets cancer cells. It blocks a specific protein found in cancer cells called BCL-2. This causes the cancer cells to stop growing and die.
Let your provider know if you have liver problems because you might need to receive Venclexta (venetoclax) treatment at a lower dose. Your provider might order blood work to check your liver health more often. In addition, because this medication is broken down by the liver, your body might have a harder time getting rid of it if you have liver problems. As a result, you might be at higher risk for side effects. Let your provider know right away if you experience symptoms of liver problems, such as extreme tiredness, stomach pain, or yellowing of the skin or whites of the eyes.
When you first begin Venclexta (venetoclax), your provider will start you at a lower dose and raise your dose slowly over time. This is done to prevent a serious condition called tumor lysis syndrome (TLS). TLS happens when cancer cells break down rapidly and release its contents, such as uric acid and electrolytes. When there’s too much uric acid and electrolytes in your body, you can experience serious kidney damage, which can be fatal. TLS is more likely to happen if you have a large tumor burden. By taking a lower dose of Venclexta (venetoclax) in the beginning and slowly raising the dose (called a"ramp-up"), your provider can lower your tumor burden and lower your risk for TLS. Your healthcare provider might recommend that you start Venclexta (venetoclax) in the hospital so they can monitor you during the ramp-up phase. Let your provider know right away if you notice symptoms of TLS, such as nausea, extreme tiredness, numbness, seeing things that aren’t there (hallucinations), and muscle cramps.
Venclexta (venetoclax) isn’t recommended for use in pregnancy. While this medication hasn’t been studied in human pregnancies, animal studies show that it might cause harm to your unborn baby. If you’re a female who’s able to become pregnant, you should use birth control while taking Venclexta (venetoclax) and for at least 1 month after the last dose. Let your provider know right away if you become pregnant while taking this medication.
It isn’t recommended to breastfeed while taking Venclexta (venetoclax). We don’t know if the medication can pass into your breast milk, but there’s a risk of serious harm to nursing infants if it does. Because of this risk, you shouldn’t breastfeed while taking Venclexta (venetoclax) and for 1 week after your last dose. Talk with your provider about other ways to feed your baby during treatment.
Venclexta (venetoclax) 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.
Treatment with Venclexta (venetoclax) can cause a serious reaction called tumor lysis syndrome (TLS). TLS is a condition where many cancer cells die quickly and suddenly break down in your body. In the process, these 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. TLS can happen as early as 6 to 8 hours after your first dose of Venclexta (venetoclax). You’re more likely to experience TLS each time your provider raises your dose.
Your provider will order labs for you regularly to check for signs of TLS. To lower your risk of TLS, your provider will start you on a lower dose of Venclexta (venetoclax) and raise your dose slowly over time. They’ll also recommend that you drink enough fluids daily to keep hydrated. If need be, they might also give you intravenous (IV) fluids and prescribe you medications to lower your uric acid levels. Tell your provider right away if you’re urinating less than usual or have dark urine, muscle cramps, or a racing heartbeat.
Venclexta (venetoclax) can cause your white blood cells, red blood cells, and platelets to drop. When these cell counts are lower than normal, you have a higher risk of anemia, bleeding, bruising, and infections. Your provider will check your blood counts often while you’re receiving Venclexta (venetoclax). Let your provider know if you develop a fever or start to feel sick or have any unusual bruising or bleeding. If this happens you might need to have your dose lowered or stop this medication altogether.
Venclexta (venetoclax) can raise your risk of serious infections, such as pneumonia and blood infection (sepsis). The infections might lead to death, especially if they’re not treated right away. Let your provider know as soon as possible if you develop a fever, chills, fatigue, cough, or have other signs of an infection.
You shouldn’t receive any live vaccines before, during, or after treatment with Venclexta (venetoclax) until your healthcare provider says it’s safe. Live vaccines contain a live, but weakened, version of the bacteria or virus they're meant to protect you from. A live vaccine could cause an infection if you have a weakened immune system, like when taking Venclexta (venetoclax). In addition, vaccines might not work as well as intended when you have a weakened immune system. Examples of live vaccines can include yellow fever, measles, mumps, and rubella, or the flu vaccine given as a nasal spray.
Based on animal studies, Venclexta (venetoclax) can harm an unborn baby. If you’re a female who’s able to become pregnant, you should use birth control during Venclexta (venetoclax) treatment and for at least 1 month after the last dose. Let your provider know right away if you become pregnant during this time.
Your provider might prescribe other anticancer medications for you to take along with Venclexta (venetoclax). Make sure to ask your provider about the specific directions and dosing of all the medications of your treatment plan.
Your dose of Venclexta (venetoclax) might differ depending on whether you're experiencing side effects or if you've any kidney or liver problems.
AML
CLL or SLL
Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Venclexta (venetoclax) will not be safe for you to take.