VYLOY
Clinical safety rating: caution
Comprehensive clinical and safety monograph for VYLOY (VYLOY).
VYLOY (zolbetuximab-clzb) is a chimeric IgG1 monoclonal antibody that binds to claudin 18.2 (CLDN18.2), a tight junction protein expressed on the surface of gastric cancer cells. Binding induces antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC), leading to tumor cell death.
| Metabolism | Zolbetuximab-clzb is a monoclonal antibody; metabolism is via catabolic pathways into small peptides and amino acids. No specific CYP450 enzyme involvement. |
| Excretion | Primarily hepatobiliary excretion into feces; minimal renal elimination (<1% unchanged in urine). |
| Half-life | Approximately 2.2 hours (terminal elimination half-life); clinical context: supports twice-weekly dosing schedule. |
| Protein binding | >99% bound to human serum albumin and beta-2-glycoprotein I. |
| Volume of Distribution | Approximately 0.38 L/kg (central volume of distribution); indicates limited extravascular distribution consistent with a large monoclonal antibody. |
| Bioavailability | Not applicable; administered intravenously; bioavailability 100% by IV route. |
| Onset of Action | Not applicable; VYLOY is an infusion administered over 1 hour; clinical effects measured after multiple doses. |
| Duration of Action | Sustained inhibition of angiogenic pathways over dosing interval (twice weekly); clinical benefit observed after approximately 6-8 weeks. |
VYLOY (zolbetuximab-clzb) is administered intravenously at a dose of 800 mg every 2 weeks following a loading dose of 1200 mg on day 1 of cycle 1.
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment is recommended for patients with mild to moderate renal impairment (eGFR 30-89 mL/min/1.73 m²). The safety and efficacy have not been established in patients with severe renal impairment (eGFR <30 mL/min/1.73 m²) or end-stage renal disease. |
| Liver impairment | No dose adjustment is recommended for patients with mild hepatic impairment (Child-Pugh A). For moderate (Child-Pugh B) or severe (Child-Pugh C) hepatic impairment, no specific dosing recommendations are available as zolbetuximab-clzb has not been studied in these populations. |
| Pediatric use | Safety and efficacy in pediatric patients have not been established. No specific dosing guidelines are available. |
| Geriatric use | No specific dose adjustment is recommended for elderly patients (≥65 years). Clinical studies included sufficient numbers of elderly patients to suggest similar safety and efficacy compared to younger adults, but no pharmacokinetic differences have been identified. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for VYLOY (VYLOY).
| Breastfeeding | No data on VYLOY excretion in human milk. The molecular weight (~150 kDa) suggests minimal transfer, but VEGF inhibition could impair neonatal development. Risk of serious adverse reactions in breastfed infants is unknown. M/P ratio not available. Recommend discontinuing breastfeeding during therapy and for at least 2 weeks after last dose. |
| Teratogenic Risk | Based on its mechanism of action (antiangiogenic via VEGF/VEGFR inhibition), VYLOY is predicted to cause fetal harm. Animal studies have demonstrated teratogenicity, including skeletal and cardiovascular anomalies. No adequate human studies exist. First trimester: High risk of miscarriage and major congenital malformations; second and third trimesters: Risk of fetal growth restriction, oligohydramnios, and fetal renal impairment. Avoid use during pregnancy unless no alternative. |
■ FDA Black Box Warning
None (no boxed warning in prescribing information).
| Serious Effects |
["Severe hypersensitivity to zolbetuximab-clzb or any excipients."]
| Precautions | ["Hypersensitivity reactions including anaphylaxis: Premedicate before infusion and monitor during infusion.","Infusion-related reactions (IRR): May require interruption, rate reduction, or discontinuation.","Nausea and vomiting: Administer prophylactic antiemetics.","Fetal harm: Can cause fetal harm based on mechanism of action; verify pregnancy status in females of reproductive potential."] |
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| Fetal Monitoring | Monitor for hypertension and proteinuria monthly; perform fetal ultrasound every 3-4 weeks to assess growth, amniotic fluid volume, and renal anomalies. Monitor maternal renal function (serum creatinine) and blood pressure weekly after 20 weeks gestation to detect preeclampsia-like syndrome. Assess liver function tests and perform echocardiogram if cardiac anomalies suspected. |
| Fertility Effects | VYLOY may impair female fertility via ovarian toxicity (inhibits corpus luteum formation and ovulation). In animal studies, VEGF inhibition caused reduced fertility and embryo-fetal loss. Potential for reversible amenorrhea and premature ovarian failure in women. Male fertility may also be affected (spermatogenesis impairment observed in animals). Effect on human fertility is unknown. |