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890 A Phase 1 Dose Escalation Trial of Third-Generation CD19-Directed CAR T-Cells Incorporating CD28 and Toll-like Receptor 2 (TLR2) Intracellular Domains for Relapsed or Refractory B-Cell Non-Hodgkin Lymphomas (ENABLE)Clinically Relevant Abstract

Program: Oral and Poster Abstracts
Type: Oral
Session: 704. Cellular Immunotherapies: Early Phase and Investigational Therapies: Improving CAR-T Therapies for B Cell Malignancies
Hematology Disease Topics & Pathways:
Research, clinical trials, Biological therapies, adult, Lymphomas, non-Hodgkin lymphoma, Clinical Research, Chimeric Antigen Receptor (CAR)-T Cell Therapies, Diseases, Therapies, Lymphoid Malignancies, Study Population, Human
Monday, December 11, 2023: 3:00 PM

Robert Weinkove, PhD1,2*, Philip George, MBBS1,2*, Robert Fyfe, MBBS1,2*, Nathaniel Dasyam, PhD1*, Yasmin Nouri, PhD1,3*, Tess Ostapowicz1,4*, Stefan Mullins, MB BCh1,2*, Brigitta Mester, PhD1*, Giulia Giunti, PhD5,6*, Catherine M. Bollard, MD7, Travis Perera, MBBS2*, Hayden Jina, MD2*, Alwyn D'Souza, MBBS2*, Le Qin, PhD8*, David S. Ritchie, MD, PhD, FRACP, FRCPA9, Chris M.A. Frampton, PhD10*, Rachel Perret, PhD1*, Peng Li, PhD8,11* and Ian Hermans, PhD1*

1Cancer Immunotherapy Programme, Malaghan Institute of Medical Research, Wellington, New Zealand
2Te Rerenga Ora Wellington Blood & Cancer Centre, Te Whatu Ora Health New Zealand Capital Coast & Hutt Valley, Wellington, New Zealand
3Division of Immunology, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
4Clinical Trials Unit, Te Whatu Ora Health New Zealand Capital Coast & Hutt Valley, Wellington, New Zealand
5Clinical Human Immunology Laboratory, Malaghan Institute of Medical Research, Wellington, New Zealand
6BioOra, Wellington, New Zealand
7Children’s National Hospital, Washington, DC
8Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
9Department of Medicine, The University of Melbourne, Parkville, VIC, Australia
10Department of Medicine, University of Otago Christchurch, Christchurch, New Zealand
11Wellington Zhaotai Therapies Limited, Wellington, New Zealand


Chimeric antigen receptor (CAR) T cell therapies directed against CD19 and incorporating either CD28 or 4-1BB intracellular co-stimulatory domains are a standard of care for relapsed or refractory (r/r) B-cell lymphomas. CD19-directed CAR T-cell products employing CD28 co-stimulation yield high response rates, but have been associated with higher rates of immune effector cell-associated neurotoxicity syndrome (ICANS) and severe cytokine release syndrome (CRS) than 4-1BB co-stimulated products. There is a need for CAR T-cell products that combine high efficacy with low toxicity.

Toll-like receptor 2 (TLR2) is expressed by T-cells, and its engagement enhances T-cell expansion, modulates cytokine production, and promotes long-lived T-cell memory. In preclinical studies, interposition of an intracellular domain from TLR2 between CD28 and CD3ζ resulted in reduced CAR T-cell production of ICANS-associated cytokines GM-CSF and IFN-γ, while maintaining production of the homeostatic cytokine IL-7. We investigated the safety and efficacy of a novel third generation CD19-directed CAR T-cell product, which combines CD28 and TLR2 co-stimulatory domains (Figure).


We completed a first-in-human phase 1 dose escalation trial of WZTL-002, comprising autologous 1928T2z CAR T-cells (‘ENABLE’, NCT04049513) for patients with r/r B-cell non-Hodgkin lymphomas (B-NHL). A 3+3 dose escalation design was used, with doses from 5 × 104 to 1 × 106 viable CAR T-cells/kg body weight. Eligible participants had radiologically assessable disease, satisfactory organ function and no central nervous system (CNS) involvement by lymphoma. Bridging therapy was permitted after leukapheresis and pending CAR T-cell manufacture and release. WZTL-002 CAR T-cells were administered intravenously after 3 days of fludarabine (30mg/m2/day) and cyclophosphamide (500mg/m2/day) lymphodepletion. Adverse events (AEs) were graded by CTCAE 5.0 except CRS and ICANS (graded by American Society for Transplantation and Cellular Therapy criteria). Response assessment was by PET/CT at month 3, per Lugano 2014 criteria. Pharmacokinetic analyses were by droplet digital PCR for CAR transgenes in blood mononuclear cells.


Of 21 patients treated within the dose escalation trial, median age was 57 years (range 23 – 70); 10 (48%) were female; 4 (19%) Māori. Lymphomas were of large cell histology in 17 (81%, Table). Participants had received a median of 4 prior lines of therapy, including autograft in 11 (52%) and allograft in 1. Product phenotyping showed WZTL-002 CAR T-cells were median 49% CD4+, 41% CD8+ and 34% CD62L+. As of June 14 2023, all patients had reached the primary follow-up timepoint (3 months after WZTL-002 administration). Grade ≥ 3 AEs occurring in ≥ 10% of recipients were: neutropenia (95%), lymphopenia (57%), hypogammaglobulinemia (57%), anaemia (43%), febrile neutropenia (43%), thrombocytopenia (24%) and tumor pain (19%). Grade 1 – 2 CRS occurred in 13 patients (62%); 6 received tocilizumab and 3 dexamethasone. No CRS of grade ≥ 3, and no ICANS of any grade, occurred. Two grade 4 cytopenia dose limiting toxicities occurred at day 21 (one each at 5 × 105 and 1 × 106 cells/kg), both resolved to grade 2 by day 90. Maximum tolerated dose was not reached. Responses were seen at all dose levels with complete metabolic response in 11 (52%) at month 3. WZTL-002 CAR T-cells expanded at all dose levels. Among recipients of 0.5 – 1.0 × 106 CAR T-cells/kg (n = 12), median peak CAR T-cell level (Cmax) was 93,950 transgene copies/μg genomic DNA (reached at median day 10) and CAR T-cells persisted in 9 of 11 assessed (82%) at day 90. A recommended phase 2 dose (RP2D) range of 0.5 – 1 × 106/kg was selected.


In this dose escalation trial of a novel third-generation CD19-directed CAR T-cell product that combines CD28 and TLR2 co-stimulatory domains for r/r B-NHL, we observed no severe CRS, no ICANS of any grade and complete responses at all dose levels. At RP2D, in vivo CAR T-cell expansion was similar to or greater than other CD19-directed products. In conjunction with preclinical findings, this study suggests interposition of a TLR2 domain between CD28 and CD3ζ domains may reduce CAR T-cell-related ICANS risk while retaining efficacy. Enrolment to a dose expansion cohort has commenced and will assess outpatient management and the safety and efficacy of WZTL-002 CAR T-cells manufactured using a closed automated process.

Disclosures: Weinkove: BioOra: Research Funding; AbbVie: Honoraria; Janssen: Honoraria, Research Funding. George: AbbVie: Honoraria. Fyfe: Janssen: Research Funding. Dasyam: BioOra: Research Funding. Mester: BioOra: Research Funding. Giunti: BioOra: Research Funding. Bollard: Roche: Consultancy; Cabaletta Bio, Catamaran Bio: Current equity holder in private company, Current equity holder in publicly-traded company, Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties: Patent applications in CAR-NKs. Ritchie: Takeda: Consultancy, Honoraria; Novartis: Honoraria, Research Funding; MSD: Honoraria; Amgen: Research Funding; BMS: Research Funding. Perret: BioOra: Research Funding. Li: Wellington Zhaotai Therapies Limited: Current equity holder in private company; Guangdong Zhaotai Biomedicine Ltd: Current equity holder in private company, Patents & Royalties. Hermans: Avalia Immunotherapies: Ended employment in the past 24 months, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties: Patents related to vaccine design; BioOra: Research Funding.

*signifies non-member of ASH