Trial Watch - bispecific T cell engagers and higher-order multispecific immunotherapeutics.

Over the past decades, cancer immunotherapy has evolved into clinical practice, with bispecific T cell engagers (TCEs) and other higher-order multispecific immunotherapeutics emerging as approaches for precision immune modulation. These engineered antibodies redirect immune effector cells toward tumor targets, thereby eliciting coordinated antitumor immune responses. While substantial clinical success has been achieved in hematologic malignancies, major challenges, such as limited activity in solid tumors, continue to constrain broader application. In this Trial Watch, we summarize recent preclinical advances in the design and optimization of TCEs and multispecific immune engager platforms together with available clinical trial data. We further examine key pharmacokinetic, safety, resistance, and manufacturing considerations in immune engager development. Collectively, these findings highlight the increasing versatility of immune cell-redirecting immunotherapies and their pivotal role in shaping the next generation of precision cancer therapy.