VENCLEXTA
Clinical safety rating: caution
Comprehensive clinical and safety monograph for VENCLEXTA (VENCLEXTA).
Selective inhibitor of B-cell lymphoma-2 (BCL-2) protein, restoring apoptosis in malignant cells.
| Metabolism | Primarily metabolized by CYP3A4; minor contribution from CYP3A5; substrate of P-glycoprotein. |
| Excretion | Primarily fecal (approximately 90% of absorbed dose), with <1% excreted renally as unchanged drug. Biliary excretion contributes to fecal elimination. |
| Half-life | Terminal elimination half-life is approximately 26 hours. Supports once-daily dosing with steady-state achieved within 3–5 days. |
| Protein binding | >99.9% bound to plasma proteins (mainly albumin and alpha-1-acid glycoprotein). |
| Volume of Distribution | Approximately 13.7 L (not weight-based; corresponds to ~0.2 L/kg for a 70 kg adult). Indicates extensive tissue distribution. |
| Bioavailability | Oral bioavailability is approximately 40–60% under fasting conditions; increased by approximately 3- to 5-fold with a high-fat meal (not recommended due to variability). |
| Onset of Action | Oral: Onset of action (tumor lysis syndrome risk) within 6–8 hours after first dose; clinical response (e.g., reduction in peripheral blood lymphocytes in CLL) may be observed within days to weeks. |
| Duration of Action | Duration of therapeutic effect is continuous with daily dosing. Dosing interruptions lead to rapid decline in plasma concentrations (elimination half-life ~26h). Continuous administration required for sustained BCL-2 inhibition. |
| Molecular Weight | 868.45 |
VENCLEXTA (venetoclax) is administered orally. For chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL): dose escalation schedule (Week 1: 20 mg daily; Week 2: 50 mg daily; Week 3: 100 mg daily; Week 4: 200 mg daily; Week 5+: 400 mg daily) in combination with obinutuzumab or rituximab. For acute myeloid leukemia (AML): 600 mg orally daily on Days 1-28 in combination with azacitidine or decitabine, or low-dose cytarabine, in 28-day cycles.
| Dosage form | TABLET |
| Renal impairment | For CLL/SLL: No dose adjustment required for mild to moderate renal impairment (CrCl ≥30 mL/min). For severe renal impairment (CrCl <30 mL/min) or dialysis: Reduce dose by 50% (e.g., target dose 200 mg daily after escalation); monitor for toxicity. For AML: No adjustment for mild to moderate renal impairment; severe impairment (CrCl <30 mL/min) not studied; use with caution and consider dose reduction. |
| Liver impairment | For CLL/SLL: Child-Pugh A: No adjustment. Child-Pugh B: Reduce dose by 50% (e.g., target 200 mg daily after escalation). Child-Pugh C: Avoid use (not recommended). For AML: Child-Pugh A: No adjustment. Child-Pugh B: Reduce dose to 400 mg daily (from 600 mg). Child-Pugh C: Avoid use. |
| Pediatric use | Safety and efficacy in pediatric patients have not been established; no approved dosing recommendations. Clinical trials ongoing; dosing based on body weight (e.g., for relapsed/refractory malignancies, starting doses of 20-400 mg/m² orally daily with escalation) may be used in investigational settings. |
| 1st trimester | Avoid due to embryo-fetal toxicity based on animal studies; effective contraception required. |
| 2nd trimester | Avoid; no human data, potential teratogenicity and fetal harm. |
| 3rd trimester | Avoid; risk of fetal toxicity and hematologic effects. |
Clinical note
Comprehensive clinical and safety monograph for VENCLEXTA (VENCLEXTA).
| Placental transfer | Venetoclax is likely to cross the placenta based on its molecular weight and animal studies showing embryo-fetal toxicity. |
| Breastfeeding | No human data; due to potential for serious adverse reactions, breastfeeding should be discontinued during therapy and for at least 1 month after last dose. |
| Lactation Rating |
■ FDA Black Box Warning
Tumor lysis syndrome (TLS): Risk is highest during initial ramp-up phase; prophylactic measures and monitoring required.
| Serious Effects |
Concomitant use with strong CYP3A inhibitors at initiation and during ramp-up phase due to risk of tumor lysis syndrome
| Precautions | Tumor lysis syndrome (TLS) - dose escalation and monitoring required, Neutropenia - monitor blood counts, Infections - increased risk, Immunization - avoid live vaccines during and after treatment, Embryo-fetal toxicity - can cause fetal harm |
| Food/Dietary | Take VENCLEXTA with food (a meal or snack) to improve absorption. Avoid grapefruit, grapefruit juice, Seville oranges, star fruit, and their juices, as they are strong CYP3A inhibitors and can significantly increase venetoclax exposure, raising the risk of toxicity. |
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| Geriatric use | No specific dose adjustment based on age alone. Elderly patients (≥65 years) are included in clinical trials; dose selection based on renal function, hepatic function, concomitant medications, and comorbidities. Monitor for increased risk of tumor lysis syndrome and hematologic toxicities. |
| L5 (Contraindicated) |
| Teratogenic Risk | Venetoclax is embryotoxic and fetotoxic in animal studies. In humans, there are no adequate data; however, based on mechanism of action (BCL-2 inhibitor), there is potential for teratogenicity. First trimester: risk of major malformations cannot be excluded. Second and third trimesters: potential for fetal growth restriction and oligohydramnios. Use only if maternal benefit outweighs fetal risk. |
| Fetal Monitoring | Monitor complete blood count (CBC) with differential throughout treatment. Assess for tumor lysis syndrome (TLS) with lab monitoring (potassium, uric acid, phosphorus, calcium, creatinine). During pregnancy, fetal ultrasound to assess growth and amniotic fluid volume; doppler studies if indicated. |
| Fertility Effects | Animal studies show no direct effects on fertility; however, venetoclax may impair male and female fertility based on its mechanism (apoptosis induction in germ cells). Clinical data are lacking; recommend fertility preservation counseling. |
| Clinical Pearls | Monitor for tumor lysis syndrome (TLS) with aggressive prophylaxis including hydration, uric acid reduction (allopurinol or rasburicase), and frequent lab monitoring of potassium, phosphate, calcium, and uric acid. Start with a 5-week ramp-up dosing schedule to mitigate TLS risk. Avoid strong or moderate CYP3A inhibitors during initiation and ramp-up; if unavoidable, reduce VENCLEXTA dose by at least 75%. For patients with CLL/SLL, check for del(17p) or TP53 mutation status. Administer with food to enhance absorption; do not crush or chew tablets. |
| Patient Advice | Take VENCLEXTA with a meal and water at the same time each day. Swallow tablets whole; do not crush, chew, or break them. · Drink plenty of water (6-8 glasses per day) during the first few weeks to reduce the risk of tumor lysis syndrome, which can be life-threatening. · Seek immediate medical attention if you experience fever, chills, muscle cramps, nausea, vomiting, diarrhea, decreased urination, or rapid weight gain. · Avoid grapefruit, Seville oranges, star fruit, and their juices as they can increase drug levels and risk of side effects. · Do not start or stop any other medications, including over-the-counter drugs or herbal supplements, without consulting your doctor. · Contact your doctor if you develop signs of infection (e.g., fever, cough, sore throat) or unusual bleeding/bruising. · Use effective contraception during treatment and for at least 30 days after the last dose. Do not breastfeed while taking VENCLEXTA. |