FDA grants fast track designation to CRISPR-edited stem cell therapy for AML
The FDA granted fast track designation to VOR33, an engineered allogeneic stem cell therapy for the treatment of patients with acute myeloid leukemia who are at high risk for relapse.
VOR33 (Vor Biopharma) comprises healthy donor hematopoietic stem cells that are gene edited using CRISPR to knock out the protein CD33. 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.
The FDA's fast track designation helps to expedite development, review and potential approval of treatments for serious or life-threatening diseases.
“Receiving fast track designation is an important milestone for Vor, which signals the FDA’s recognition of the serious and life-threatening medical condition of patients facing acute myeloid leukemia and the potential of VOR33 to address this unmet medical need,” Robert Pietrusko, PharmD, chief regulatory and quality officer with Vor, said in a company-issued press release. “We will continue to work closely with the FDA to expedite the development of VOR33.”
Vor began enrollment of a phase 1/phase 2A clinical trial of VOR33 earlier this year. The study includes patients with CD33-positive AML who are at high risk for relapse.
The multicenter trial is designed to assess the safety and feasibility of VOR33 for hematopoietic stem cell transplant. 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.
Initial clinical data on the trial should be made publicly available during the first half of 2022, Pietrusko said in the release.