Last reviewed 2026-04-20 · How we verify

Mylotarg (GEMTUZUMAB)

Mylotarg targets and binds to CD33-positive cancer cells, delivering a cytotoxic agent to destroy them.

Mylotarg (gemtuzumab) is a CD33-directed immunoconjugate monoclonal antibody used to treat acute myeloid leukemia (AML). It works by targeting and binding to CD33-positive cancer cells, delivering a cytotoxic agent to destroy the cells. Mylotarg is approved for use in both newly-diagnosed and relapsed or refractory CD33-positive AML patients. The drug is patented and owned by Wyeth Pharmaceuticals Inc. Key safety considerations include potential infusion reactions and hematologic toxicity.

At a glance

Mechanism of action

Gemtuzumab ozogamicin is a CD33-directed antibody-drug conjugate (ADC). The antibody portion (hP67.6) recognizes human CD33 antigen. The small molecule, N-acetyl gamma calicheamicin, is a cytotoxic agent that is covalently attached to the antibody via a linker. Nonclinical data suggest that the anticancer activity of gemtuzumab ozogamicin is due to the binding of the ADC to CD33-expressing tumor cells, followed by internalization of the ADC-CD33 complex, and the intracellular release of N-acetyl gamma calicheamicin dimethyl hydrazide via hydrolytic cleavage of the linker. Activation of N-acetyl gamma calicheamicin dimethyl hydrazide induces double-strand DNA breaks, subsequently inducing cell cycle arrest and apoptotic cell death.

Approved indications

• newly-diagnosed CD33-positive acute myeloid leukemia (AML)
• relapsed or refractory CD33-positive AML

Boxed warnings

• WARNING: HEPATOTOXICITY Hepatotoxicity, including severe or fatal hepatic veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), has been reported in association with the use of MYLOTARG as a single agent, and as part of a combination chemotherapy regimen. Monitor frequently for signs and symptoms of VOD after treatment with MYLOTARG. ( 5.1 and 6.1 ) WARNING: HEPATOTOXICITY See full prescribing information for complete boxed warning. Hepatotoxicity, including severe or fatal hepatic veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), has been reported in association with the use of MYLOTARG. ( 5.1 , 6.1 )

Common side effects

• infection
• hemorrhage
• veno-occlusive liver disease

Key clinical trials

• Gemtuzumab Ozogamicin in Treating Older Patients With Previously Untreated Acute Myeloid Leukemia (PHASE2,PHASE3)
• Azacitidine and Gemtuzumab Ozogamicin in Treating Older Patients With Previously Untreated Acute Myeloid Leukemia (PHASE2)
• MYELOMATCH: A Screening Study to Assign People With Myeloid Cancer to a Treatment Study or Standard of Care Treatment Within myeloMATCH (MyeloMATCH Screening Trial) (PHASE2)
• Testing the Addition of Venetoclax or Gemtuzumab Ozogamicin (GO) to Usual Treatment Regimen (Cytarabine and Daunorubicin, "7+3") for Core Binding Factor Acute Myeloid Leukemia (CBF-AML) to Improve Response (A MyeloMATCH Treatment Trial) (PHASE2)
• Fludarabine Phosphate, Cytarabine, Filgrastim-sndz, Gemtuzumab Ozogamicin, and Idarubicin Hydrochloride in Treating Patients With Newly Diagnosed Acute Myeloid Leukemia or High-Risk Myelodysplastic Syndrome (PHASE2)
• A Study To Learn About the Safety Medicine (Called Mylotarg) In People With Acute Myeloid Leukemia
• Geriatric Assessment & Genetic Profiling to Personalize Therapy in Older Adults With Acute Myeloid Leukemia (PHASE2)
• IMPACT-AML: A Randomized Pragmatic Clinical Trial for Relapsed or Refractory Acute Myeloid Leukemia. (PHASE3)

Patents

Primary sources

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Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• Mylotarg CI brief — competitive landscape report
• Mylotarg updates RSS · CI watch RSS
• Wyeth Pharms Inc portfolio CI