Please check your internet connection and try again.
# Mylotarg (gemtuzumab ozogamicin)
## Overview
Mylotarg is a CD33-directed antibody-drug conjugate (ADC) consisting of a monoclonal antibody linked to calicheamicin, a potent cytotoxic agent. It induces DNA double-strand breaks, leading to cell cycle arrest and apoptosis in CD33-positive cells.
## Primary Indications
* Newly diagnosed CD33-positive acute myeloid leukemia (AML) in adults and pediatric patients aged 1 month and older.
* Relapsed or refractory CD33-positive AML in adults and pediatric patients aged 2 years and older.
## Adult Dosing
Dosage is based on body surface area (BSA) and the specific chemotherapy regimen (e.g., in combination with daunorubicin and cytarabine or as monotherapy).
* **Newly diagnosed AML (Combination):** 3 mg/m² (up to a maximum dose of 4.5 mg) on days 1, 4, and 7.
* **Relapsed/Refractory AML:** 3 mg/m² (up to a maximum dose of 4.5 mg) on days 1, 4, and 7.
* *Note: Always verify specific induction/consolidation protocols as dosing timing may vary significantly.*
## Pediatric Dosing
* **Aged 1 month and older (Newly diagnosed):** 3 mg/m² on days 1, 4, and 7 (max 4.5 mg/dose). If BSA is < 0.6 m², the dose is 0.1 mg/kg.
* **Aged 2 years and older (Relapsed/Refractory):** 3 mg/m² on days 1, 4, and 7 (max 4.5 mg/dose). If BSA is < 0.6 m², dose at 0.1 mg/kg.
## Dose Adjustments
* **Hepatic Impairment:** Avoid in patients with severe hepatic impairment (Total bilirubin > 2x ULN, AST/ALT > 2.5x ULN). No dose adjustment required for mild impairment.
* **Renal Impairment:** No specific dosing adjustments provided in current labeling.
* **Toxicity:** Dose delays or discontinuation may be required for severe infusion-related reactions (IRR), unresolved hepatotoxicity, or prolonged hematologic recover.
## Contraindications
* Known hypersensitivity to gemtuzumab ozogamicin or any excipients.
* Severe hepatic impairment.
## Adverse Effects
* **Hepatotoxicity:** Including veno-occlusive disease (VOD/sinusoidal obstruction syndrome).
* **Hematologic:** Severe neutropenia, thrombocytopenia, and anemia.
* **Infusion-Related Reactions:** Fever, chills, hypotension, and dyspnea.
* **Infection:** Elevated risk of opportunistic infections.
* **Tumor Lysis Syndrome:** Risk associated with rapid cytoreduction.
## Key Drug Interactions
* **Hepatotoxic Agents:** Use with extreme caution as these may increase the risk of VOD.
* **Live Vaccines:** Avoid live virus vaccines during therapy due to immunosuppression.
## Monitoring
* **Baseline/Frequent:** LFTs (bilirubin, AST, ALT, alkaline phosphatase) before each dose.
* **During Infusion:** Monitor for signs of IRRs (e.g., hypotension/dyspnea) for at least 1 hour post-infusion.
* **Hematology:** CBC with differential frequently to monitor for recovery and cytopenias.
* **VOD:** Monitor for signs of hepatotoxicity, including rapid weight gain, RUQ pain, jaundice, and ascites.
## Clinical Pearls
* **Pre-medication:** Mandatory premedication with a corticosteroid, antihistamine, and antipyretic 30–60 minutes prior to infusion to attenuate IRRs.
* **Stability:** Must be protected from light during preparation and administration. Reconstituted vials must be used immediately or refrigerated (2–8°C) for up to 16 hours.
* **VOD Risk:** The risk of VOD is highest in patients undergoing hematopoietic stem cell transplantation (HSCT) post-Mylotarg. Close monitoring of liver enzymes is critical.
***
**Educational Disclaimer:** This information is for educational purposes only and does not replace professional clinical judgment. Dosing and administration protocols vary by institution and patient-specific factors. Always consult the most recent FDA-approved prescribing information and your local hematology/oncology guidelines before prescribing or dispensing.
