Investigational new drug application for VOR33 cleared by the FDA

On January 14, 2021, the U.S. Food and Drug Administration (FDA) cleared the investigational new drug (IND) application for VOR33 in patients at risk of relapse with acute myeloid leukemia (AML).

VOR33

The engineered hematopoietic stem cell (eHSC) therapy, VOR33, involves reconstitution with cells lacking CD33. The rationale behind this is to allow for subsequent treatment with the CD33-directed antibody–drug conjugate, gemtuzumab ozogamicin, while limiting myelosuppression and the resulting toxicities.

The clearance of the IND application allows the initiation of a phase I/IIa trial, which will evaluate the safety and feasibility of VOR33 in patients with CD33⁺ AML who will likely relapse. Investigators hope to determine whether VOR33 can engraft sufficiently. Following successful engraftment, enrolled patients will be offered treatment with gemtuzumab ozogamicin, with the hope to improve leukemia-free survival.

HSC with VOR33 may be an effective approach in achieving hematopoietic reconstitution that is resistant to CD33-targeted therapies, thereby improving posttransplant outcomes in patients with AML.