Vor Biopharma (VOR) Study Update summary

Study design and patient population

• VBP-101 is a phase 1/2 study evaluating Trem-cel, a CRISPR-edited CD33-negative stem cell transplant, followed by post-transplant Mylotarg in high-risk AML and MDS patients.

• Patients had high-risk features: 17% with active disease, 11% MRD+, 61% adverse cytogenetics, 44% secondary AML, and 25% with TP53 mutations.

• All 18 patients in the data cut received successfully manufactured Trem-cel with a median CD33 editing efficiency of 89%.

• Median neutrophil engraftment was 9 days and platelet recovery 16.5 days, with 100% achieving primary neutrophil engraftment and full donor myeloid chimerism by day 28.

• Trem-cel is positioned as a platform enabling multiple targeted therapy modalities, including ADCs and CAR-Ts.

Efficacy and safety outcomes

• Post-transplant Mylotarg was administered at 0.5, 1, and 2 mg/m² doses, with 40 cycles given across patients.

• Platelet and neutrophil counts remained stable post-Mylotarg, indicating effective shielding by Trem-cel.

• Mylotarg exposure (AUC) at 2 mg/m² matched that of 9 mg/m² in standard AML, with Cmax well below VOD risk threshold and no Mylotarg-related SAEs or significant liver toxicity.

• Only two of ten patients receiving Mylotarg relapsed, both with TP53 mutations and at lower Mylotarg doses.

• Early evidence indicates prolonged relapse-free survival and patient benefit with the Trem-cel and Mylotarg combination.

Comparative outcomes and future plans

• Median relapse-free survival (RFS) for VBP-101 patients has not been reached, appearing favorable versus historical controls (median RFS 3.8–6.2 months in comparator studies).

• The next pivotal study will randomize high-risk AML patients to Trem-cel plus Mylotarg versus standard of care, with RFS as the primary endpoint and enrollment at the 2 mg/m² Mylotarg dose.

• Early discussions with regulators are planned to refine trial design, including control arm selection and timing of Mylotarg administration.

• Potential exists to move Mylotarg administration earlier post-transplant, pending safety data.

• The platform approach aims to address a market opportunity exceeding $1B and potentially change the standard of care in blood cancers.