Vor Bio announces new clinical data from VBP101 study

Vor Bio announced new clinical data from its ongoing Phase 1/2 VBP101 study of patients with relapsed/refractory AML receiving trem-cel followed by Mylotarg. The data demonstrated reliable engraftment, shielding from Mylotarg on-target toxicity, a broadened Mylotarg therapeutic window, and early evidence of patient benefit. Reliable engraftment, with 100% of patients achieving primary neutrophil engraftment and robust platelet recovery. High CD33 editing efficiency and full myeloid chimerism at Day 28. Shielding of the blood system, with maintained neutrophil and platelet counts across multiple Mylotarg doses of 0.5, 1, and 2 mg/m2. Broadened therapeutic index for Mylotarg with drug exposure represented by AUC which is related to efficacy, consistent with labeled Mylotarg doses, and with maximal concentrations, measured by Cmax and related to veno-occlusive disease, well below known toxic range. Early evidence suggesting patient benefit as measured by relapse-free survival when compared to published high-risk AML comparators. Vor Bio plans to approach the FDA to discuss a trial design for trem-cel + Mylotarg by around year end. VCAR33ALLO represents another potentially significant synergistic treatment option after trem-cel. The VBP301 study continues enrolling patients with initial focus on relapsed/refractory AML post-transplant. Vor Bio is encouraged by in vivo CAR-T expansion data from three patients treated to date, all at the lowest dose of 1 x 106 CAR+ cells/kg. VADC45 is an ADC that targets the CD45 protein. CD45 is a well-validated target for a wide variety of blood cancers with clinical proof of concept. The linker-payload used in VADC45 is also clinically validated. VADC45 has the potential to treat a number of diseases, including treatment of hematologic malignancies, as a targeted conditioning agent for gene therapies such as for sickle cell disease, holistic immune reset for autoimmune disorders, and for Vor Bio’s approach of combining this asset with epitope modification of CD45 to shield healthy stem cells. Vor Bio already has preclinical data for VADC45 and is progressing IND-enabling studies to enable future Phase 1 studies.