SL4903

SL4903 is an autologous chimeric antigen receptor (CAR) T-cell therapy targeting the G protein-coupled receptor class C group 5 member D (GPRC5D), currently under investigation for the treatment of relapsed or refractory multiple myeloma (r/r MM), with a specific focus on patients with extramedullary disease (EMD). GPRC5D is highly and selectively expressed on malignant plasma cells, including those in extra-osseous sites, while having minimal expression in normal tissues, making it a promising target for patients who have relapsed following BCMA-targeted therapies. The therapy involves the ex vivo genetic modification of a patient's T-cells to express a CAR specific to GPRC5D; once re-infused into the patient, these engineered cells identify and eliminate myeloma cells through T-cell mediated cytotoxicity. SL4903 is being evaluated in Phase 1 trials to determine its safety profile and maximum tolerated dose (MTD) using a 3+3 dose escalation model.