Potency monitoring of CAR T cells

Identification of the conditions and minimum requirements necessary for the release of autologous fresh CAR T-cell products under hospital exemption: a position paper from the WP-bioproduction of the UNITC consortium

The accessibility of CAR-T cells in centralized production models faces significant challenges, primarily stemming from logistical complexities and prohibitive costs. However, European Regulation EC No. 1394/2007 introduced a pivotal provision known as the hospital exemption. This exemption enables academic institutions to produce ATMPs, including autologous CAR-T cells, under GMP conditions tailored to specific needs. In response to this regulatory framework, our work group has launched a guideline initiative. This endeavor aims to bolster academic CAR T-cell manufacturing by implementing strategic workshops that serve a dual purpose: standardizing production processes and ensuring both efficacy and safety standards are met. This inaugural focused on delineating criteria for the release of fresh CAR-T cell batches. Key emphases included thorough product characterization, stringent safety and potency evaluations. These criteria are essential for compliance with regulatory mandates and aligning with industry best practices. Notably, the release of initial CAR T-cell batches will be facilitated through provisional certification, with final certification contingent upon the acquisition of comprehensive analytical control results. This procedural framework adheres to methodologies endorsed by the SFGM-TC and the EBMT. Such adherence underscores a commitment to harmonizing practices across academic manufacturing facilities, thus fortifying the accessibility, efficacy, and safety of point-of-care units.

Locoregional delivery of IL-13Rα2-targeting CAR-T cells in recurrent high-grade glioma: a phase 1 trial

Chimeric antigen receptor T cell (CAR-T) therapy is an emerging strategy to improve treatment outcomes for recurrent high-grade glioma, a cancer that responds poorly to current therapies. Here we report a completed phase I trial evaluating IL-13Rα2-targeted CAR-T cells in 65 patients with recurrent high-grade glioma, the majority being recurrent glioblastoma (rGBM). Primary objectives were safety and feasibility, maximum tolerated dose/maximum feasible dose and a recommended phase 2 dose plan. Secondary objectives included overall survival, disease response, cytokine dynamics and tumor immune contexture biomarkers. This trial evolved to evaluate three routes of locoregional T cell administration (intratumoral (ICT), intraventricular (ICV) and dual ICT/ICV) and two manufacturing platforms, culminating in arm 5, which utilized dual ICT/ICV delivery and an optimized manufacturing process. Locoregional CAR-T cell administration was feasible and well tolerated, and as there were no dose-limiting toxicities across all arms, a maximum tolerated dose was not determined. Probable treatment-related grade 3+ toxicities were one grade 3 encephalopathy and one grade 3 ataxia. A clinical maximum feasible dose of 200 × 106 CAR-T cells per infusion cycle was achieved for arm 5; however, other arms either did not test or achieve this dose due to manufacturing feasibility. A recommended phase 2 dose will be refined in future studies based on data from this trial. Stable disease or better was achieved in 50% (29/58) of patients, with two partial responses, one complete response and a second complete response after additional CAR-T cycles off protocol. For rGBM, median overall survival for all patients was 7.7 months and for arm 5 was 10.2 months. Central nervous system increases in inflammatory cytokines, including IFNγ, CXCL9 and CXCL10, were associated with CAR-T cell administration and bioactivity. Pretreatment intratumoral CD3 T cell levels were positively associated with survival. These findings demonstrate that locoregional IL-13Rα2-targeted CAR-T therapy is safe with promising clinical activity in a subset of patients. ClinicalTrials.gov Identifier: NCT02208362 .