Safety and PK/PD data on the use of ALLO-647 for lymphodepletion in R/R LBCL and FL patients

Allogeneic CAR T-cell therapies represent a potentially readily accessible therapeutic alternative derived from healthy donors. However, ensuring a secure and efficient method to regulate host lymphocyte rejection (allo-rejection) is imperative.

This presentation elucidates the safety and PK/PD outcomes of ALLO-647, an anti-CD52 monoclonal antibody, in patients with R/R LBCL and FL.

A total of 87 patients participated in the ALPHA and ALPHA2 studies, encompassing those with R/R LBCL (n=61), including 34 who were naive to CAR T-cell therapy, and FL (n=26). The patients were treated with ALLO-647, before undergoing CAR T-cell infusion, with the doses administered 39, 60, and 90 mg in 11 (13%), 39 (45%), and 37 (43%) patients, respectively. The median follow-up period was 29.5 months (range, 6.8-47.5).

There were no unforeseen safety issues, GvHD or ICANS of ≥ grade 3 observed. Approximately 24% of the patients experienced low-grade CRS, with only one patient experiencing ≥ grade 3 CRS. The predominant infection event was low-grade and manageable CMV reactivation. Patients who exhibited a positive lymphoma response generally received higher doses of ALLO-647, indicating a dose-dependent relationship.

In conclusion, this data suggests that ALLO-647 provides an immediately available, safe, and single-dosing option for patients eligible for CAR T-cell therapy.

Reference:

Locke FL et al (2023) ALLO-647 for Lymphodepletion in the Allogeneic CAR T Setting: Safety Experience with ALLO-501/501A in Patients (Pts) with Relapsed/Refractory (r/r) Large B-Cell and Follicular Lymphomas. Blood 142 (Supplement 1): 2095.

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