Vor Bio's Trem-cel Shows Early Encouraging Data In Leukemia Patients

Vor Biopharma Inc VOR presented updated data from patients treated in the VBP101 Phase 1/2a study of trem-cel (formerly VOR33) in acute myeloid leukemia patients.

The time for neutrophil engraftment in all five patients treated with trem-cel (10-11 days) was similar to unedited transplants.

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, 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.

These patients have not experienced any unexpected adverse events to date.

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.

The FDA also cleared the company's Investigational New Drug (IND) application for VCAR33ALLO, a T-cell therapy derived from allogeneic healthy donors using a chimeric antigen receptor (CAR) specifically binding to CD33. 

VCAR33ALLO is planned to be studied in the VBP301 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.

Price Action: VOR shares are up 0.94% at $5.38 on the last check Friday.