French early nationwide idecabtagene vicleucel chimeric antigen receptor T-cell therapy experience in patients with relapsed/refractory multiple myeloma (FENIX): A real-world IFM study from the DESCAR-T registry.

Idecabtagene vicleucel (ide-cel), a chimeric antigen receptor T-cell therapy targeting B-cell maturation antigen (BCMA), received early access program (EAP) authorization in France in April 2021 for relapsed/refractory multiple myeloma (RRMM). We conducted a real-world registry-based multicentre observational study in 11 French hospitals to evaluate ide-cel outcomes. Data from 176 RRMM patients who underwent apheresis between June 2021 and November 2022 were collected from the French national DESCAR-T registry. Of these, 159 patients (90%) received ide-cel. Cytokine release syndrome occurred in 90% with 2% grade ≥3, and neurotoxicity occurred in 12% with 3% grade ≥3. Over the first 6 months, the best overall response and ≥complete response rates were 88% and 47% respectively. The median progression-free survival (PFS) from the ide-cel infusion was 12.5 months, the median overall survival (OS) was 20.8 months and the estimated OS rate at 12 months was 73.3%. Patients with extra-medullary disease (EMD) had impaired PFS (6.2 months vs. 14.8 months). On multivariable analysis, EMD and previous exposure to BCMA-targeted immunoconjugate or T-cell-redirecting GPRC5D bispecific antibody were associated with inferior PFS. Our study supports ide-cel's feasibility, safety and efficacy in real-life settings, emphasizing the importance of screening for EMD and considering prior treatments to optimize patient selection.

Development of ISB 1442, a CD38 and CD47 bispecific biparatopic antibody innate cell modulator for the treatment of multiple myeloma.

Antibody engineering can tailor the design and activities of therapeutic antibodies for better efficiency or other advantageous clinical properties. Here we report the development of ISB 1442, a fully human bispecific antibody designed to re-establish synthetic immunity in CD38+ hematological malignancies. ISB 1442 consists of two anti-CD38 arms targeting two distinct epitopes that preferentially drive binding to tumor cells and enable avidity-induced blocking of proximal CD47 receptors on the same cell while preventing on-target off-tumor binding on healthy cells. The Fc portion of ISB 1442 is engineered to enhance complement dependent cytotoxicity, antibody dependent cell cytotoxicity and antibody dependent cell phagocytosis. ISB 1442 thus represents a CD47-BsAb combining biparatopic targeting of a tumor associated antigen with engineered enhancement of antibody effector function to overcome potential resistance mechanisms that hamper treatment of myeloma with monospecific anti-CD38 antibodies. ISB 1442 is currently in a Phase I clinical trial in relapsed refractory multiple myeloma.