Vor Bio Announces Clinical Data Validating Shielded Transplants for Targeted Therapies

BOSTON--PureTech Health plc (Nasdaq: PRTC, LSE: PRTC) ("PureTech" or the "Company"), a clinical-stage biotherapeutics company focused on transforming the lives of patients suffering from severe illnesses, highlighted recent clinical findings from one of its Founded Entities, Vor Bio (Nasdaq: VOR). Vor Bio, a clinical-stage cell and genome engineering company, has shared promising new data from its ongoing Phase 1/2 VBP101 study involving patients with relapsed or refractory acute myeloid leukemia (AML) being treated with trem-cel followed by Mylotarg™. The results highlight successful engraftment, protection from Mylotarg’s on-target toxicity, an expanded therapeutic window for Mylotarg, and initial signs of patient benefit.

Vor Bio's recent announcement emphasized that trem-cel, when used in conjunction with Mylotarg, showed promising results in terms of engraftment and protection, potentially offering significant benefits to AML patients who have historically faced poor outcomes even post-transplant. Dr. Eyal Attar, Chief Medical Officer at Vor Bio, expressed optimism about the data and indicated plans to proceed with a registrational trial while exploring other synergistic opportunities within Vor Bio’s platform, including VCAR33 ALLO and VADC45.

The data presented from the study included results from 18 patients treated with trem-cel, with ten having received Mylotarg by the data cut-off date of July 19, 2024. Key findings included:

1. Reliable Engraftment: All patients achieved primary neutrophil engraftment (median of 9 days) and robust platelet recovery (median of 16.5 days). Additionally, there was high CD33 editing efficiency (median 89%, range 71-94%) and full myeloid chimerism by Day 28.
2. Shielding: The blood system was protected, with maintained neutrophil and platelet counts across various Mylotarg doses (0.5, 1, and 2 mg/m²).
3. Broadened Therapeutic Index: The therapeutic index for Mylotarg was broadened, with drug exposure (AUC) related to efficacy and maximal concentrations (Cmax) related to veno-occlusive disease remaining well below the known toxic range.
4. Early Patient Benefit: Preliminary evidence suggested a benefit in terms of relapse-free survival compared to published high-risk AML comparators.

Dr. Guenther Koehne, an investigator in the VBP101 study, expressed confidence in the safety of this approach, as supported by the data. He looks forward to treating more high-risk relapse patients using this trial, given the limited outcomes with standard transplants.

Vor Bio plans to engage with the U.S. Food & Drug Administration to discuss a pivotal trial design for the combination of trem-cel and Mylotarg by the end of the year.

In addition to the progress with trem-cel and Mylotarg, Vor Bio is advancing other promising assets:

1. VCAR33 ALLO: This represents a significant synergistic treatment option post-trem-cel. The VBP301 study is enrolling patients focusing initially on those with relapsed or refractory AML post-transplant. Preliminary in vivo data from three patients treated with the lowest dose show encouraging CAR-T expansion.
2. VADC45: Announced as a new preclinical asset with opportunities in oncology, gene therapy, and autoimmune disorders, VADC45 is an antibody-drug conjugate (ADC) targeting the CD45 protein, a well-validated target for various blood cancers. VADC45’s linker-payload is also clinically validated and holds potential for treating hematologic malignancies, serving as a targeted conditioning agent for gene therapies, holistic immune reset for autoimmune disorders, and combining with epitope modification of CD45 to shield healthy stem cells. Vor Bio is progressing with IND-enabling studies to facilitate future Phase 1 trials.

Vor Bio continues to push boundaries in the field of cell and genome engineering, aiming to revolutionize the standard of care for patients with blood cancers by enabling targeted therapies post-transplant.

How to obtain the latest research advancements in the field of biopharmaceuticals?

In the Synapse database, you can keep abreast of the latest research and development advances in drugs, targets, indications, organizations, etc., anywhere and anytime, on a daily or weekly basis. Click on the image below to embark on a brand new journey of drug discovery!