Pronunciation: ven-neet-o-clacks
Generic name: venetoclax
Brand name: Venclexta
Dosage form: oral tablet
Drug class: Miscellaneous antineoplastics

Medically reviewed by Carmen Pope, BPharm. Last updated on Oct 7, 2024.

What is venetoclax?

Venetoclax (brand name Venclexta) may be used to treat chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) in adults, or newly diagnosed acute myeloid leukemia (AML) in those aged 75 years or older, or with other conditions that prevent intensive chemotherapy. For AML, venetoclax is used in combination with azacitidine, decitabine, or low-dose cytarabine.

Venetoclax's mechanism of action (MOA) involves targeting a specific protein called BCL-2. BCL-2 acts like a cell's on/off switch for death, preventing a natural process called apoptosis (programmed cell death) from eliminating unwanted cells. Cancerous blood cells, particularly in CLL, SLL, and AML, often overproduce BCL-2, making them resistant to traditional chemotherapy. Venetoclax binds directly to BCL-2, essentially flipping the cell's death switch back on causing the cell to die. Venetoclax is not chemotherapy, it is a targeted treatment  (see Is Venclexta chemotherapy? for more information).

Venetoclax gained FDA approval on April 11, 2016, under the brand name Venclexta. There is no generic Venclexta.

Venetoclax side effects

The most common side effects of venetoclax are:

• Laboratory test changes, such as low white cell counts, low platelet counts, and low red blood cell counts
• Diarrhea
• Nausea
• Upper respiratory tract infections (such as a cold)
• Cough
• Muscle and joint pain
• Tiredness
• Swelling of your arms, legs, hands, and feet.

Other side effects that are common when venetoclax is used to treat AML include:

• Constipation
• Fever
• Vomiting
• Shortness of breath
• Bleeding
• Rash
• Stomach (abdominal) pain
• An infection in your blood
• Muscle and joint pain
• Dizziness
• Sore throat
• Low blood pressure.

Serious side effects and warnings

Venetoclax can cause the following serious side effects.

Venetoclax can cause tumor lysis syndrome (TLS), which can lead to kidney failure, dialysis treatment, and possibly death. TLS is caused by the fast breakdown of cancer cells and your healthcare provider will do tests to check your risk of TLS before you start taking venetoclax, and will give you medicines to help reduce your risk before starting and during treatment. Make sure you keep your regular appointments for blood tests and tell your healthcare provider right away if you have any symptoms of TLS during treatment, such as fever, chills, nausea, vomiting, confusion, shortness of breath, seizures, irregular heartbeat, dark or cloudy urine, unusual tiredness, or muscle or joint pain

• Drink 6 to 8 glasses (about 56 ounces total) of water each day, starting 2 days before your first dose, on the day of your first dose, and each time your dose is increased, to help reduce your risk of getting TLS.
• When restarting venetoclax after stopping for 1 week or longer, your healthcare provider may again check for your risk of TLS and change your dose.

Low white blood cell counts (neutropenia) have been reported with venetoclax. These are common but can also be severe. Your healthcare provider will do blood tests to check your blood counts during treatment and may pause dosing.

Infections. Serious, sometimes fatal, infections such as pneumonia and blood infections (sepsis) have occurred during venetoclax treatment. Tell your healthcare provider right away if you develop any symptoms of an infection, such as fever, difficulty breathing, rash, tiredness, or feeling faint.

Venetoclax may harm an unborn child. Females who can have children should use effective contraception while taking venetoclax and for 30 days after the last dose. Venetoclax may also cause fertility problems in males which may affect their ability to father a child. Talk to your healthcare provider if you have concerns about fertility.

Venetoclax may cause an allergic reaction. Get emergency medical help if you have signs of an allergic reaction to venetoclax. Symptoms may include hives; difficulty breathing; or swelling of your face, lips, tongue, or throat.

Do not receive live attenuated vaccines (such as MMR, chickenpox, Monkeypox) before, during, or after treatment with venetoclax until your B-cells have made a full recovery.

Tell your doctor about all your current medicines and any you start or stop using. Many drugs can interact with venetoclax, and some drugs should not be used together.

These are not all the possible side effects of venetoclax. See the Venetoclax Prescribing Information for a complete list. Call your doctor for medical advice about side effects. You may report side effects to AbbVie Inc. at 1-800-633-9110 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch

Venetoclax price

Venetoclax is only available as the brand Venclexta. The cost of venetoclax varies depending on your insurance plan and which pharmacy you use. Refer to our price guide page for more information about Venclexta 's cost.

You may also be eligible for an Venclexta coupon, or Venclexta copay card. Ask your doctor or pharmacist if you qualify. There is no Venclexta generic.

Before taking this medicine

To make sure venetoclax is safe for you, tell your doctor if you:

• have kidney problems
• have liver problems
• have problems with your body salts or electrolytes, such as potassium, phosphorus, or calcium
• have a history of high uric acid levels in your blood or gout
• are scheduled to receive a vaccine. You should not receive a “live vaccine” before, during, or after treatment with venetoclax until your healthcare provider tells you it is okay. If you are not sure about the type of immunization or vaccine, ask your healthcare provider. These vaccines may not be safe or may not work as well during treatment.
• are pregnant or plan to become pregnant
• are breastfeeding or plan to breastfeed.

Pregnancy

Venetoclax may harm an unborn baby. You may need a pregnancy test to make sure you are not pregnant. Use birth control while using venetoclax and for at least 30 days after your last dose. Tell your doctor if you become pregnant.

Breastfeeding

It is not known if venetoclax passes into your breast milk. You should not breastfeed while using this medicine and for at least 1 week after your last dose.

Male fertility

It may be harder for a man to get a woman pregnant while using this medicine.

How should I take venetoclax?

Take venetoclax exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose.

• Venetoclax is usually taken once a day.
• Venetoclax dosing begins with a 5-week ramp-up (see dosing information below).
• Your healthcare provider will tell you what dose of venetoclax to take. Your dose usually started low and then increased slowly over several weeks.
• You may receive your first dose in a hospital or clinic setting to quickly treat any serious side effects.

Take venetoclax with food and water, at the same time each day.

• Do not crush, chew, or break a tablet. Swallow the tablet or tablet whole.
• Tell your healthcare provider if you have trouble swallowing Venclexta 100 mg tablets. They may prescribe your dose in smaller-sized tablets.
• To prevent certain side effects, drink 6 to 8 glasses of water daily for 2 days before you start taking venetoclax. Also, drink 6 to 8 glasses of water on the day you first take this medicine, and whenever your dose is changed.

Do not stop using this medicine without first asking your doctor.

Call your doctor at once if you have:

• symptoms of sepsis - confusion, severe drowsiness, rapid breathing, feeling very ill
• signs of pneumonia - cough with yellow or green mucus, stabbing chest pain, wheezing, trouble breathing
• low blood cell counts - fever, mouth sores, skin sores, easy bruising, unusual bleeding, pale skin, cold hands and feet, feeling light-headed
• signs of tumor cell breakdown - chills, joint or muscle pain, feeling tired or short of breath, fast or slow heartbeats, nausea, vomiting, dark or cloudy urine, or seizure (convulsions).

Venetoclax dosing

Recommended dosage of venetoclax for CLL/SLL

The dosage of venetoclax is usually increased slowly over 5 weeks, as per the venetoclax package insert:

• Week 1: Venetoclax 20 mg 1 time a day
• Week 2: Venetoclax 50 mg 1 time a day
• Week 3: Venetoclax 100 mg 1 time a day
• Week 4: Venetoclax 200 mg 1 time a day
• Week 5 and beyond: Venetoclax 400 mg 1 time a day.

The Venclexta Starting Pack provides the first 4 weeks of venetoclax according to the ramp-up schedule.

See the Venclexta Prescribing Information for venetoclax dosing when used in combination with obinutuzumab or rituximab.

The maintenance dosage of venetoclax is 400 mg once daily after completion of the 5-week ramp-up dosing schedule.

Venetoclax is taken until your cancer progresses or you have unacceptable side effects from venetoclax, whatever comes first. 

Recommended dosage of venetoclax for AML

The dosage of venetoclax is usually increased slowly over 3 or 4 days, as per the venetoclax package insert:

• Day 1: Venetoclax 100 mg 1 time a day
• Day 2: Venetoclax 200 mg 1 time a day
• Day 3: Venetoclax 400 mg 1 time a day
• Day 4 and beyond: Venetoclax 400 mg once daily of each 28-day cycle in combination with azacitidine or decitabine OR Venetoclax 600 mg once daily of each 28-day cycle in combination with low-dose cytarabine.

Venetoclax should be continued in combination with combination with azacitidine, decitabine, or low-dose cytarabine until your cancer progresses or you have unacceptable side effects from venetoclax, whatever comes first. 

What happens if I miss a dose?

If you miss a dose of venetoclax and it has been less than 8 hours, take your dose as soon as possible. If you miss a dose and it has been more than 8 hours, skip the missed dose and take the next dose at your usual time.

If you vomit shortly after taking venetoclax, do not take another tablet. Take your next dose as scheduled the next day.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking venetoclax?

Avoid receiving a "live" vaccine while receiving venetoclax because the vaccine may not work as well. Live vaccines include measles, mumps, rubella (MMR), rotavirus, typhoid, yellow fever, varicella (chickenpox), and zoster (shingles).

Grapefruit, starfruit, and Seville oranges may interact with venetoclax and cause unwanted side effects. Avoid consuming grapefruit products, starfruit, and orange marmalades.

What other drugs will affect venetoclax?

Other drugs may interact with venetoclax, and affect the blood levels of other drugs you take, which may increase side effects or make the medications less effective. Tell your pharmacist or healthcare provider about all the medicines you take, including any prescription and over-the-counter medicines, vitamins, or herbal supplements. Especially tell them if you take:

• antibiotic or antifungal medications
• heart medications
• antiviral medications to treat hepatitis C or HIV.
• strong or moderate CYP3A inhibitors or P-gp inhibitors, such as posaconazole, clarithromycin, and ketoconazole. The dosage of venetoclax will need adjusting.
• strong or moderate CYP3A inducers, such as carbamazepine, fosphenytoin, or dexamethasone. Taking these drugs at the same time as venetoclax should be avoided
• P-gp substrates, such as apixaban, colchicine, cyclosporine, dabigatran, digoxin, edoxaban, rivaroxaban, or tacrolimus. Take these medications at least 6 hours before venetoclax.

You should also avoid grapefruit, grapefruit products, Seville oranges, or starfruit during treatment with venetoclax because these prevent venetoclax from being metabolized properly and increase your risk of side effects.

Not all possible interactions are listed here. See the venetoclax prescribing information for a full list of interactions.

Related/similar drugs

Imbruvica, rituximab, cyclophosphamide, Rituxan, vincristine, Calquence, venetoclax, Venclexta, azacitidine, cytarabine

Storage

Venetoclax is only available as the brand Venclexta. Store Venclexta tablets in their original container at room temperature, away from moisture and heat. Do not put the tablets into a daily pill box.

Keep out of reach of children.

Venclexta ingredients

Venetoclax is only available under the brand Venclexta.

Active ingredient: venetoclax

Inactive ingredients: copovidone, colloidal silicon dioxide, polysorbate 80, sodium stearyl fumarate, and calcium phosphate dibasic.

Film coating (10 mg and 100 mg tablets): iron oxide yellow, polyvinyl alcohol, polyethylene glycol, talc, and titanium dioxide.

Film coating (50 mg tablets): iron oxide yellow, iron oxide red, iron oxide black, polyvinyl alcohol, talc, polyethylene glycol, and titanium dioxide.

Available as Venclexta 10 mg, 50 mg, and 100 mg tablets.

Who makes venetoclax

AbbVie Inc., makes venetoclax as the brand Venclexta.

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Further information

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