BTL-101

BTL-101 is a fully human trispecific T-cell engager (TCE) designed for the treatment of relapsed/refractory multiple myeloma (RRMM). It simultaneously targets two tumor-associated antigens, B-cell maturation antigen (BCMA) and G protein-coupled receptor class C group 5 member D (GPRC5D), while engaging CD3 on T cells to induce tumor cell lysis. The molecule features an affinity-optimized CD3 arm intended to provide potent cytotoxicity while tempering cytokine release (e.g., IL-6, TNF-α) to improve safety. By targeting two antigens, BTL-101 aims to mitigate the risk of relapse driven by antigen escape, a common limitation of single-antigen directed therapies. It has demonstrated resistance to soluble BCMA interference and superior potency compared to combinations of existing bispecific therapies in preclinical models. BTL-101 is currently being evaluated in Phase I/II clinical trials.