VOR Vor Biopharma Inc

Clinical Update

On June 9, 2023, the Company presented updated clinical data from patients treated in VBP101, its Phase 1/2a multicenter, open-label, first-in-human study of trem-cel in patients with AML. The time for neutrophil engraftment in all five patients treated with trem-cel (10-11 days) was similar to unedited transplants, suggesting that CD33 may be biologically dispensable. All patients achieved high levels of myeloid donor chimerism by day 28.

After achieving timely neutrophil engraftment and platelet recovery, patient 2 experienced secondary graft failure coincident with a detected coronavirus hKU1 infection and following administration of antimicrobial agents including trimethoprim-sulfamethoxazole, both of which may be associated with graft failure. A backup graft was administered, and neutrophil engraftment and platelet recovery were observed.

Patient 3 achieved timely neutrophil engraftment at Day 10, however platelets are still recovering. A platelet-reactive antibody was identified, and the patient is being treated for autoimmune thrombocytopenia. Platelets are steadily increasing and are at 15,000 per µL independent of transfusions.

Patients 4 and 5 achieved normal neutrophil engraftment and platelet recovery, providing further confidence in the Company’s platform and approach. These patients have not experienced any unexpected adverse events to date.

Cell doses for all five patients were successfully manufactured and met release criteria, and all had a high level of CD33 editing efficiency.

As previously reported, neutrophil and platelet cell counts were maintained in patient 1 who received multiple Mylotarg doses at 0.5 mg/m², suggesting protection from Mylotarg-induced hematotoxicity.

Regulatory Update

The Company also announced on June 9, 2023 that the U.S. Food and Drug Administration has cleared its Investigational New Drug application for VCAR33^ALLO, a T-cell therapy derived from allogeneic healthy donors using a chimeric antigen receptor specifically binding to CD33.

VCAR33^ALLO is planned to be studied in the VBP301 clinical trial, which will focus on patients who have relapsed following allogeneic stem cell transplant where T cells harvested from the original donor are used as starting material for the drug product.