ZIRABEV
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ZIRABEV (ZIRABEV).
ZIRABEV (bevacizumab-awwb) is a vascular endothelial growth factor (VEGF) inhibitor. It binds to VEGF-A and prevents its interaction with VEGFR-1 and VEGFR-2 receptors on endothelial cells, thereby inhibiting angiogenesis.
| Metabolism | Not extensively metabolized; primarily eliminated via proteolytic catabolism. |
| Excretion | ZIRABEV (bevacizumab) is eliminated primarily via metabolic degradation in the reticuloendothelial system. Renal excretion is minimal (<1% as unchanged drug in urine). Biliary/fecal excretion accounts for the remainder of metabolites. |
| Half-life | Terminal elimination half-life is approximately 20 days (range 11-50 days). This long half-life supports extended dosing intervals (e.g., every 2-3 weeks). |
| Protein binding | Bevacizumab is approximately 95% bound to plasma proteins (likely albumin). |
| Volume of Distribution | Volume of distribution (Vd) at steady state is about 2.9-3.1 L/kg, indicating distribution primarily within the vascular and interstitial spaces, consistent with a large monoclonal antibody. |
| Bioavailability | Intravenous: 100% (not administered via other routes). Subcutaneous absorption is minimal and not clinically used; subcutaneous bioavailability has not been characterized. |
| Onset of Action | Intravenous: Clinical antiangiogenic effects (e.g., reduction in vascular permeability) may be observed within 1-2 weeks after first dose, though maximal response may require multiple doses. |
| Duration of Action | Pharmacodynamic effects (e.g., suppression of tumor angiogenesis) persist for several weeks after drug clearance due to sustained VEGF inhibition. Dosing interval is typically 2-3 weeks. |
| Molecular Weight | 149000 |
15 mg/kg intravenously over 60 minutes on Day 1 of each 3-week cycle
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment (CrCl >= 30 mL/min). Insufficient data for severe renal impairment (CrCl < 30 mL/min) or dialysis. |
| Liver impairment | No dose adjustment recommended for Child-Pugh A or B. Not studied in Child-Pugh C; use with caution. |
| Pediatric use | Safety and efficacy not established in pediatric patients. |
| Geriatric use | No specific dose adjustment required based on age alone; monitor for adverse effects. |
| 1st trimester | Avoid. Bevacizumab is teratogenic in animal studies; no adequate human data. Risk of fetal harm. |
| 2nd trimester | Avoid. Continued risk due to anti-angiogenic effects; potential for fetal malformations. |
| 3rd trimester | Avoid. May cause oligohydramnios due to impaired fetal renal function; use only if benefit justifies risk. |
Clinical note
Comprehensive clinical and safety monograph for ZIRABEV (ZIRABEV).
| Placental transfer | Therapeutic antibodies such as bevacizumab cross the placenta, especially in the second and third trimesters. Fetal serum levels can reach maternal levels. |
| Breastfeeding | Not recommended during breastfeeding due to potential for serious adverse reactions in the infant. Bevacizumab is a large protein expected to be present in milk at low levels, but systemic absorption is possible. |
■ FDA Black Box Warning
Gastrointestinal perforations, wound dehiscence, and hemorrhage (including fatal hemoptysis) have been reported. Discontinue ZIRABEV in patients with these events.
| Serious Effects |
Hypersensitivity to bevacizumab or any excipientsUntreated CNS metastases (risk of hemorrhage)Recent hemoptysis (≥1/2 teaspoon of red blood)
| Precautions | Gastrointestinal perforations, Wound dehiscence, Hemorrhage (including severe or fatal hemoptysis), Arterial thromboembolic events (e.g., stroke, myocardial infarction), Venous thromboembolic events (e.g., pulmonary embolism), Hypertension (including hypertensive crisis), Posterior reversible encephalopathy syndrome (PRES), Renal injury and proteinuria, Congestive heart failure, Ovarian failure, Fetal harm (use effective contraception during and for 6 months after treatment) |
| Food/Dietary | No known food interactions. No dietary restrictions required. |
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| Lactation Rating | L5 - Contraindicated |
| Teratogenic Risk | ZIRABEV (bevacizumab) is contraindicated in pregnancy due to its anti-angiogenic mechanism. First trimester exposure is associated with increased risk of fetal malformations (e.g., skeletal anomalies, omphalocele) and spontaneous abortion. Second and third trimester exposure can cause fetal renal impairment, oligohydramnios, and fetal growth restriction due to inhibition of placental vascular development. |
| Fetal Monitoring | Baseline and serial blood pressure monitoring, urinalysis for proteinuria, and renal function tests (serum creatinine, BUN) every 2-3 weeks. Pregnant patients require close fetal surveillance with ultrasound for fetal growth, amniotic fluid volume, and Doppler velocimetry; monitor for hypertension and proteinuria (pre-eclampsia-like syndrome). |
| Fertility Effects | Bevacizumab may impair ovarian function and fertility in females due to anti-angiogenic effects on ovarian vasculature. Reversibility is uncertain. Advise fertility preservation counseling. Effects on male fertility are unknown. |
| Clinical Pearls | ZIRABEV (bevacizumab-awwb), a biosimilar to bevacizumab, is an anti-VEGF monoclonal antibody. Administer as IV infusion; do not administer as IV push or bolus. Premedication is not routinely required. Monitor blood pressure every 2-3 weeks during treatment; hypertension is common and may require antihypertensive therapy. Assess urine protein via dipstick; hold for ≥2+ proteinuria and resume only if resolves to ≤1+. Discontinue for severe hemorrhage, GI perforation, wound dehiscence, or arterial thromboembolic events. Use with caution in patients with prior venous thromboembolism or recent surgery (wait ≥28 days post major surgery). |
| Patient Advice | Inform your healthcare provider immediately if you experience severe headache, vision changes, seizures, or chest pain, as these may indicate serious side effects like hypertensive crisis or blood clots. · Report any unusual bleeding, black/tarry stools, coughing up blood, or vomiting blood, as this drug increases bleeding risk. · Do not undergo elective surgery or dental procedures without informing your doctor, as this medication can impair wound healing and should be stopped at least 28 days before surgery. · Women of childbearing age must use effective contraception during treatment and for at least 6 months after the last dose, as ZIRABEV can harm a fetus. · Avoid aspirin or blood thinners unless specifically prescribed by your doctor, as they may further increase bleeding risk. · Attend all regular blood pressure and urine protein monitoring appointments, as these are essential to prevent serious kidney or cardiovascular complications. |