South Korea-based clinical-stage biopharmaceutical company TiumBio Co., Ltd. (Kosdaq: 321550) announced on Friday that it has dosed its first patient in its phase two clinical trial of its oral immuno-oncology drug TU2218.

TU2218 is a potentially first-in-class dual inhibitor targeting transforming growth factor beta receptor 1 (TGFR1) and vascular endothelial growth factor receptor 2 (VEGFR2). It is expected to improve the efficacy of immune checkpoint inhibitors (ICIs) by blocking TGF-beta and VEGF pathways.

During Phase 1a and 1b clinical trials, the company assessed the safety, pharmacokinetics and pharmacodynamics of TU2218 as a monotherapy and in combination with Keytruda (pembrolizumab) in 41 patients with advanced solid tumours. These profiles were used to assess the dose levels for Phase two trials. The Phase 2a trial is engineered to evaluate the safety and efficacy of TU2218 in combination with Keytruda in patients with head and neck squamous cell carcinoma (HNSCC), biliary tract cancer (BTC), and colorectal cancer (CRC).

The Phase 2 trial begins at Seoul National University Hospital and Asan Medical Center in South Korea, which is planned to expand to hospitals in the United States. The first dose was administered to an HNSCC patient.

The company says that in the Phase 1b trial, among 10 patients with advanced solid tumours that received a 195mg daily dose (the determined dose for Phase 2) of TU2218 with Keytruda, three patients achieved partial response (PR) and five patients had stable disease (SD), yielding an 80% disease control rate (DCR).