Current use and future development of gemtuzumab ozogamicin

Area of Science:

• Hematology
• Oncology
• Pharmacology

Background:

• CD33 antigen is a target in 80-90% of acute myeloid leukemia (AML) cases.
• CD33 is absent on hematopoietic stem cells, making it a selective target.
• Gemtuzumab ozogamicin delivers a cytotoxin to CD33-expressing cells.

Purpose of the Study:

• To evaluate the efficacy and safety of gemtuzumab ozogamicin as a single agent.
• To assess response rates, survival, and adverse events in patients with relapsed AML.
• To determine the drug's effectiveness in untreated first relapse CD33+ AML.

Main Methods:

• Multicenter trials involving 142 patients with CD33+ AML in first relapse.
• Administration of two doses of gemtuzumab ozogamicin (9 mg/m2) 14 days apart.
• Assessment of overall response rate, survival, relapse-free survival, and safety.

Main Results:

• Overall response rate was 30% across all patients.
• Median survival was 5.9 months, with 31% survival at 1 year.
• Infusion-related syndromes and severe myelosuppression were common; hepatic and mucocutaneous toxicities were infrequent.
• No significant difference in response based on age or duration of first remission.

Conclusions:

• Gemtuzumab ozogamicin demonstrates a notable response rate in relapsed CD33+ AML.
• The drug is associated with manageable toxicities, including infusion reactions and myelosuppression.
• Further studies are ongoing to explore its use in combination therapies for AML.