TiumBio Co., Ltd. announced interim results from the Phase 1b clinical trial of TU2218 in combination with pembrolizumab at the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting. TU2218 is a novel oral dual inhibitor targeting transforming growth factor beta receptor 1 (TGFR1) and vascular endothelial growth factor receptor 2 (VEGFR2). TGF-ss and VEGF pathways in tumor microenvironment interfere with the anti-tumor activity of immune checkpoint inhibitors, so TU2218 is expected to maximize the efficacy of immuno-therapies by inhibiting them.

TiumBio's ongoing Phase 1b clinical trial (NCT05784688) in the United States evaluates safety, pharmacokinetics, and preliminary efficacy of TU2218 in collaboration with Keytruda (pembrolizumab) in patients with advanced solid tumors. The study consists of three dosage groups (105 mg, 150 mg, and 195 mg/day), and the presentation at the ASCO Annual Meeting included results from 12 patients across the three cohorts. Data from the full Phase 1b trial, which includes 18 patients, will be available in the second half of 2024.

In the poster released at the 2024 ASCO Annual Meeting, five patients treated at the recommended phase 2 dose (RP2D) of 195mg/day TU2218 in combination With pembrolizumab demonstrated an ORR of 40% at PR (n=2) and 60% at SD (n=3) with a DCR of 100%. And across all dosage groups, patients (n=12) receiving the combination therapy showed PR at 16.7% (n=2), SD at 50.0% (n=6) and PD at 25.0% (n=3). In this study, TU2218 was well-tolerated as a combination therapy with pembrolizumumab, showing no signs of DLTs, which is consistent with a previous monotherapy trial.