SCB-333 (4-1BBL-Trimer): Immuno-Oncology

SCB-333 is a novel fusion protein consisting of 4-1BBL (CD137 Ligand) and our proprietary Trimer-Tag©, allowing 4-1BBL to form a stable covalently-bound trimeric fusion protein.

4-1BB is one of the most promising immune costimulatory targets with the potential to be combined with checkpoint inhibitor therapies (e.g. PD-1) to synergistically stimulate the immune system’s anti-tumor response.

Activation of 4-1BB on activated T cells stimulates proliferation and survival of the tumor-specific cytotoxic T cells and promotes development of the innate immune memory response. 4-1BBL is a natural trimer, and its receptor (4-1BB) must be trimerized in order to be activated.

All current 4-1BB targeted candidates currently in clinical trials are agonistic monoclonal antibodies (dimeric mAbs). The development of such mAbs has been hindered by dose-limiting severe hepatic toxicities. We believe that SCB-333, with its favorable pharmacokinetic profile and natural receptor-activating potency, could potentially overcome such hurdles observed to date.

SCB-333 is currently in preclinical development.