Adicet Bio, Inc. announced that an abstract detailing updated safety and efficacy data from the Company's Phase 1 study of ADI-001 for the potential treatment of relapsed or refractory B-cell Non-Hodgkin's lymphoma (NHL) was made available as part of the 64th American Society of Hematology (ASH) Annual Meeting, which is being held December 10-13, 2022 in New Orleans, Louisiana. The abstract outlines a summary of clinical data as of a July 15, 2022 data-cut date. Clinical data will be provided during a poster presentation by Sattva Neelapu, M.D., from the MD Anderson Cancer Center at the ASH Annual Meeting on Saturday, December 10, 2022.

Data highlights as of the July 15, 2022 data-cut date included in the ASH abstract were as follows: Of the nine evaluable patients, three patients were treated at each of the three dose levels: dose level 1 (DL1; 30 million CAR+ cells), dose level 2 (DL2; 100 million CAR+ cells), and dose level 3 (DL3; 300 million CAR+ cells). Two patients at DL3 were re-dosed with a second course of ADI-001, per protocol. Six of nine were male (67%) and the median age was 62 years (range 45-75).

There were eight patients with large B-cell lymphoma (LBCL) and one with mantle cell lymphoma. Of the eight patients with LBCL, five had diffuse-large B-cell lymphoma (DLBCL), two had high-grade B-cell lymphoma (HGBCL) with double/triple hit, and one had HGBCL not otherwise specified. Indolent lymphomas, such as follicular lymphoma, are currently excluded from the study.

Overall, the patients were heavily pretreated with a median number of prior therapies of four (range 2-5), and had a poor prognostic outlook as indicated by the median International Prognostic Index (IPI) score of four (range 2-4); the median tumor burden was 2,974 (150-7,919) mm2, and 89% (8/9) had stage III/IV disease. The best overall response rate (ORR) and complete response rate (CR) was 78% (7/9). For the four patients who had prior autologous CD19 CAR T therapies, the ORR and CR rate was 100% (4/4).

As of the data-cut date, of the seven patients who had achieved CR, two patients progressed, one died of unrelated causes while in complete remission and four were still in CR and in active follow up, with a range of follow-up time between 1.2 and 8.8 months. CAR+ gamma delta T cell kinetics in the peripheral blood increased in a dose-dependent manner with peak cell expansion occurring between Days seven and 10 at DL3 based on flow cytometry. Of the nine patients, there were no = Grade 3 Cytokine Release Syndrome (CRS) or Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS) events.

Two patients developed CRS: one Grade 1 and one Grade 2. At the time of the ASH abstract submission, there were three reported related serious adverse events: Grade 2 CRS, Grade 1 ICANS and Grade 3 adenoviraemia. There was no reported graft versus host disease or protocol-defined dose-limiting toxicity events. Response data were evaluated per Lugano 2014 criteria by independent radiographic review.