SUZHOU, China, April 21, 2021 /PRNewswire/ -- Transcenta Holding Limited (Transcenta), a clinical stage global biotherapeutics company with fully-integrated capabilities in discovery, development and manufacturing of antibody-based therapeutics, today announced that it has received clearance of its IND for TST005 from US FDA for initiating Phase I clinical trial of its bi-functional anti-PD-L1/TGF-β antibody.

TST005, is a bi-functional anti-PD-L1 and TGF-β trap fusion protein designed to simultaneously target two immuno-suppressive pathways, transforming growth factor -β (TGF-β) and programmed cell death ligand-1 (PD-L1), that are commonly used by cancer cells to evade the immune system. TST005 consists of a high affinity PD-L1 antibody fused with an engineered TGF-β Receptor Type II protein in its C-terminal. TST005 lacks FcR binding activity and thus has reduced FcR mediated killing of PD-L1 expressing effector T cells. TST005's high PD-L1 binding activity and enhanced TGF-β trap stability enables the targeted delivery of TGF-β trap into PD-L1 expressing tumors, thereby minimizing off-target toxicities of systemic inhibition of TGF-β signaling. TST005 displayed potent activity in vitro in reversing TGF-β induced T-cell suppression. In multiple syngeneic tumor models, TST005 induced significant increase of CD8 T-cell infiltration into PD-L1 expressing tumors and displayed dose-dependent tumor growth inhibition in tumor model with high level TGF-β. TST005 is well tolerated in non-human primates and displayed a linear PK profile. TST005 is a potential novel bi-functional immunotherapy candidate with improved therapeutic window. 

"TST005 is one of the few leading PD-L1/TGF-β bi-functional antibody drug candidates currently in clinical development globally," said Dr. Michael Shi, Transcenta's EVP, Head of Global R&D and CMO, "We plan to simultaneously develop TST005 both in China and the United States under the same Phase I protocol with an innovative basket trial design. With the IND Clearance for TST005 in the US, we will accelerate the clinical development globally by allowing Chinese patients dosed at the current dose level when joining the study upon Chinese IND clearance. Once safety and tolerability are established, we plan to further evaluate TST005 in multiple other pretreated tumor types globally, benefiting patients worldwide at an early date."