Gemtuzumab Ozogamicin: Time to Resurrect?

On May 17, 2000, the US Food and Drug Administration (FDA) granted accelerated approval for the use of gemtuzumab ozogamicin (GO) in older patients (age ≥ 60 years) with acute myeloid leukemia (AML) in first relapse who were not considered candidates for standard cytotoxic chemotherapy.1 Approval for this novel anti-CD33 immunoconjugate was based on a phase II trial demonstrating a 30% response rate (including complete response [CR] and CR with incomplete platelet recovery)2 and was conditional on future demonstration of benefit in treatment of AML. Over the past 10 years, several phase II and III trials have addressed this issue.