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Background: Single target CD19 and dual-targeting BCMA-CD19 chimeric antigen receptor (CAR) T-cell therapy has shown promise in the treatment of autoimmune diseases. All FDA approved CD19 CAR-T treatments utilize murine derived single-chain fragment variable (scFv), FMC63 clone, comprised of light and heavy chains joined by an immunogenic peptide linker. Neutralizing antibodies against the CAR scFv have been detected and undermine the ability to re-dose CAR-T cells. To overcome this limitation, we engineered a novel camelid nanobody CAR-T platform. The camelid nanobody sequencing has demonstrated high homology to humans and thus is unlikely to induce an immunogenic response and will increase efficacy. We have created a novel BCMA-CD19 nanobody-based compound CAR-T cell therapy (ncCAR) to target both B and plasma cells. BCMA-CD19 ncCAR was manufactured using the Neo-G process, to shorten manufacturing time by 3-4 days and enhance the efficacy. To date, this is the first study to report preclinical efficacy and clinical safety of ncCAR.
Objectives: Preclinical studies were designed to evaluate safety and efficacy of ncCAR.
Methods: Alpacas were immunized with human BCMA and CD19 proteins to generate nanobody (VHH) libraries. Specific VHH candidates were identified using phage display, ELISA, and flow cytometry, followed by validation of binding kinetics through biolayer interferometry. Nanobody-based CAR constructs were designed for BCMA-CD19 ncCAR. Patient T cells were purified and engineered using the Neo-G manufacturing process. Human T cells were transduced with BCMA-CD19 ncCAR and assessed for cytotoxic efficacy in vitro using co-culture assays with BCMA⁺ and CD19⁺ target cell lines. In vivo studies were conducted in NSG (NOD-scid gamma) mouse models engrafted with target cells, followed by infusion of BCMA-CD19 ncCAR. A phase I clinical study is underway to evaluate the safety of ncCAR.
Results: ncCAR-T cells demonstrated potent and specific cytotoxicity against BCMA+ and CD19+ cells in vitro. Co-culture assays showed significant lysis of target cells. In mouse models, BCMA-CD19 ncCAR effectively depleted BCMA+ and CD19+ cells, with durable persistence of CAR-T cells. A patient suffering from multiple myeloma (MM) and thrombocytopenia has been compassionately dosed with ncCAR and has demonstrated remarkable safety and efficacy. The patient achieved stringent complete remission (sCR) of MM with resolution of high burden disease in the marrow and soft tissues and thormbocytopenia with normalization of platelets. sCR was confirmed by serum free light chain, PET/CT and flow cytometry analysis. Updated results in our phase I clinical trial evaluating ncCAR in treatment of systemic lupus erythematosus (SLE) and other diseases will be reported at the meeting.
Conclusion: This is the first known use of the novel ncCAR. ncCAR has demonstrated exceptional safety and efficacy in preclinical use. The BCMA-CD19 ncCAR targets CD19+ B cells and BCMA+ long-lived plasma cells which are the “root cause” of autoantibody production. The resolution of ITP validates the ability of ncCAR to deplete humoral cells driving autoimmune disease. Therefore, this study supports the expanded investigation of ncCAR to treat autoimmune diseases.
REFERENCES: NIL.
Acknowledgements: NIL.
Disclosure of Interests: Byeong-Hyeok Choi Employee of iCell Gene Therapeutics Inc., Kai Zhang: None declared, Hsing-Ming Chang Employee of iCell Gene Therapeutics Inc., Vincent DeStefano Employee of iCell Gene Therapeutics Inc., Jing Luo Employee of iCell Gene Therapeutics Inc., Yu Ma Employee of iCAR Bio Therapeutics Ltd, Nabil Hagag Employee of iCell Gene Therapeutics Inc., Ahmed Abdel-Razek Employee of iCell Gene Therapeutics Inc., Yupo Ma Dr. Yupo Ma is the founder of iCell Gene Therapeutics Inc., Jing He: None declared.
© The Authors 2025. This abstract is an open access article published in Annals of Rheumatic Diseases under the CC BY-NC-ND license (