Clinical Results of a First-in-Human Phase 1 Study of Point-of-Care Manufactured Bispecific Anti-CD19, Anti-CD20 Chimeric Antigen Receptor Modified T (CAR-20.19-T) Cells for Relapsed, Refractory, Non-Hodgkin Lymphoma (NHL)

Background CAR-T cell therapy against the CD19 antigen is a breakthrough treatment for patients (pts) with relapsed/refractory (R/R) B-cell NHL. Despite impressive outcomes, non-response and relapse with CD19 negative disease remains a clinical challenge. Through dual B-cell antigen targeting of CD20 and CD19, with a first-in-human bispecific CAR-T cell (CAR-20.19-T), we hope to improve response rates while limiting relapses due to target antigen loss. To optimize production and eliminate third party shipping logistics we utilized point of care automated manufacturing using the CliniMACS Prodigy, a compact GMP compliant tabletop device. Methods Phase 1 dose escalation + expansion trial (NCT03019055) to demonstrate feasibility of point of care manufacturing and safety of a bispecific 41BB/CD3z CAR-20.19-T cell for adults with R/R B-cell NHL. Feasibility goal was u003e75% successful production rate. Safety was assessed by incidence of dose limiting toxicities (DLTs) within 28 days post-infusion. Dose was escalated in a 3+3 fashion with a starting dose of 2.5 × 10^5 cells/kg and a target cell dose of 2.5 × 10^6 cells/kg. CAR-T manufacturing set at 14 days for all pts. All pts received lymphodepletion with fludarabine 30 mg/m2 × 3 days and cyclophosphamide 500 mg/m2 × 1 day. Clinically appropriate pts received fresh CAR-T cell infusion while others received CAR-T cells after cryopreservation. Results 8 pts have received treatment and completed their DLT monitoring period: 3 pts at 2.5 × 10^5 cells/kg, 3 pts at 7.5 × 10^5 cells/kg, and 2 pts at 2.5 × 10^6 cells/kg. 4 pts had MCL, 2 pts had DLBCL, and 2 pts had CLL (Figure 1). CAR-T production reached target dose in all pts indicating 100% feasibility. Five pts received fresh CAR-T cells and 3 pts received CAR-T cells after cryopreservation. To date there are no DLTs to report. No patient experienced grade 3-4 cytokine release syndrome (CRS) or neurotoxicity (NTX). 3 pts had Grade 2 CRS and 1 patient had Grade 2 NTX. Median time to CRS was Day +9 post-infusion and no patient required ICU level care. Day 28 responses (Figure 1) are as follows: 4/8 pts complete response (CR) including both at the highest dose level, 2/6 pts partial response (PR), and 2/6 pts had progressive disease (PD). CAR-T cell persistence up to day 90 is presented in Figure 2. All PD pts underwent repeat biopsy, and all retained either CD19 or CD20 positivity. Additional pts are being enrolled at 2.5 × 10^6 cells/kg dose. Conclusions Point of care manufacturing via CliniMACS Prodigy and therapy with bispecific CAR-20.19-T cells is feasible and safe for pts with R/R B-cell NHL. Down-regulation of target antigens was not identified as a mechanism of CAR-T failure in this cohort. With no DLTs to date and 4/8 heavily pre-treated pts achieving CR at day +28 with longest CR u003e1 year, this approach to CAR-T production and dual B-cell targeting merits further investigation.