By Fineline Cube 
China-based Sichuan Huiyu Pharmaceutical Co., Ltd. (SHA: 688553) announced that its wholly-owned subsidiary, Huiyu Haiyue, has completed the first patient dosing in a Phase I clinical trial for its self-developed Class 1 innovative biological drug, HY05350 for injection (R&D code: HY-0005). This trispecific antibody T-cell engager (TCE) targets CD3, MSLN, and PD-L1 and is intended for the treatment of MSLN-positive advanced solid tumors.
Clinical Trial Progress
The clinical trial application for HY05350 was accepted by China’s National Medical Products Administration (NMPA) in April 2025 and received clinical trial approval in June 2025. The ongoing Phase I/II clinical study is a multi-center, open-label trial designed to evaluate the safety, tolerability, pharmacokinetics, and preliminary efficacy of HY05350. The study will also determine the maximum tolerated dose (MTD) and recommend a dose for further study (RP2D).
Innovation and Market Potential
HY05350 represents an innovative product not yet marketed in or outside of China. Preclinical studies have demonstrated its good anti-tumor activity and safety profile. Currently, there are no approved products with the same target on the market, positioning HY05350 as a promising therapeutic option for MSLN-positive advanced solid tumors.-Fineline Info & Tech