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 2022 American Society of Clinical Oncology (ASCO) Annual Meeting, to be held June 3-7, 2022. The abstract provides a summary of clinical data as of a February 14, 2022, data-cut date. Data highlights as of the February 14, 2022 data-cut date included in the ASCO abstract were as follows: Six evaluable patients were enrolled in dose level 1 (DL1; 30 million CAR+ cells) and dose level 2 (DL2; 100 million CAR+ cells), 33% (2/6) were female and the median age was 62 years (range 45-75).

There were five patients with large B-cell lymphoma and one with mantle cell lymphoma. Indolent lymphomas, such as follicular lymphoma, are currently not enrolled in the study. Overall, the patients were heavily pretreated with a median number of prior therapies of 3.5 (range 2-5) and had a poor prognostic outlook as indicated by the median International Prognostic Index (IPI) score of 3.5 (range 2-4).

One patient previously progressed following two prior treatments with autologous anti-CD19 CAR T cell therapy (lisocabtagene maraleucel) prior to receiving ADI-001. At Day 28, the overall response rate (ORR) and the complete response (CR) rate based upon independent central reading by PET/CT were 67% (4/6 patients). As of the February 14, 2022 data-cut date, of the four patients who achieved CR after treatment with ADI-001: Two patients remained in CR with = three months post-treatment follow-up, including a triple-hit large B-cell lymphoma patient who had previously progressed following two administrations of autologous anti-CD19 CAR-T and a total of five lines of prior therapy.

As previously disclosed, one patient, a 66-year-old female who had responded to ADI-001, developed COVID-19 related pneumonia approximately two and a half months after ADI-001 administration and later died of complications from it, unrelated to ADI-001. This patient was previously reported as a partial response (PR) by local radiological assessment and has been assessed as a CR by independent central reading. One patient with a CR had not reached the three-month assessment date as of the data-cut date for the ASCO abstract submission.

Safety data from the trial at the February 14, 2022 data-cut date were consistent with the previously reported well tolerated profile, with no occurrence of Grade = 3 Cytokine Release Syndrome (CRS), Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS) or Graft vs Host Disease. No dose-limiting toxicities were documented. All response data have been determined per protocol by independent central reading of PET/CT per Lugano (2014) criteria.