Immuno-Oncology Resource Center
Immuno-Oncology Resource Center

Press Release

January 14, 2021
1 min read

FDA clears IND application for stem cell therapy to treat AML


Press Release

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The FDA cleared an investigational new drug application for VOR33, an engineered stem cell therapy for the treatment of patients with acute myeloid leukemia who are at high risk for relapse, according to the agent’s manufacturer.

VOR33 (Vor Biopharma) is a hematopoietic stem cell therapy that is genetically engineered to lack the CD33 protein. Removal of this protein allows for subsequent treatment with gemtuzumab ozogamicin (Mylotarg, Pfizer) — a CD33-directed antibody drug conjugate — while avoiding the known toxicities of CD33-directed therapies.

Photomicrograph of bone marrow aspirate showing myeloblasts of acute myeloid leukemia (AML), a cancer of white blood cells.
Source: Adobe Stock.

The IND clearance will permit Vor Biopharma to begin a phase 1/phase 2A trial of VOR33. The study will enroll patients with CD33-positive AML who are at high risk for relapse.

The trial will assess the safety and feasibility of VOR33 for HSCT and will focus on confirming that the investigational stem cell therapy can engraft normally after transplantation. After successful engraftment, patients in the study will receive gemtuzumab ozogamicin to evaluate whether it can prolong leukemia-free survival and prevent myelosuppression typically associated with CD33-directed therapies.

Vor Biopharma said it plans to initiate the phase 1/phase 2A trial in the first half of this year.

“Though advances have been made in the treatment of AML and other myeloid malignancies, the median overall 5-year survival rate for patients diagnosed with AML remains under 30 percent,” Christopher Slapak, MD, chief medical officer of Vor Biopharma, said in a company-issued press release. “We engineered VOR33 to provide patients with a hematopoietic stem cell transplant that we believe, upon hematopoietic reconstitution, will be treatment resistant to CD33-targeted therapies, potentially resulting in new treatment options and improved post-transplant outcomes.”