TiumBio's 'Oral Immuno-Oncology Drug' Interim Results of Phase 1b Clinical Trial "Partial Response Confirmed in 2 Patients"

TiUM Bio will reveal the interim results of the Phase 1b clinical trial of TU2218, an oral immuno-oncology drug under development, at the American Society of Clinical Oncology (ASCO).

Kim Hoon-taek, CEO of Tium Bio [Photo by Lee Chun-hee]

TiUM Bio announced on the 24th that the ongoing Phase 1b clinical trial in the U.S., combining TU2218 with the blockbuster immuno-oncology drug Keytruda, showed an interim disease control rate (DCR) of 66.7% (8 patients), including 2 patients (16.7%) with partial response. However, the ASCO abstract released on the 23rd (local time) indicated only 1 patient (8.3%) with partial response. The company explained, "At the time of abstract submission, the patient was in a state of disease progression, but it was recently confirmed that the patient converted to partial response," adding, "The poster to be presented at ASCO on the 1st of next month will include the updated data showing 2 patients with partial response."

The evaluation of anticancer treatment efficacy is generally classified into four categories: ▲Complete response, where all tumors disappear and no recurrence occurs for a certain period ▲Partial response, where tumors shrink by more than 50% ▲Stable disease, where the initial state is maintained ▲Progressive disease, where tumors grow by more than 25% or new tumors appear. Since the combination therapy trial of TU2218 targets patients with advanced progressive solid tumors, the interim results confirmed that 66.7% of the 12 evaluated patients, including those with partial response and stable disease (6 patients), achieved disease control.

TU2218 is the first dual inhibitor in its class that simultaneously blocks the pathways of transforming growth factor (TGF)-beta (ß) and vascular endothelial growth factor (VEGF), which interfere with the activity of immuno-oncology drugs in the body, thereby maximizing the efficacy of immuno-oncology drugs like Keytruda. The Phase 1b trial is currently underway in the U.S. as a combination therapy with Keytruda. This Phase 1b trial is divided into three dosing groups according to TU2218 dosage, with TU2218 administered orally twice daily for two weeks, and Keytruda administered intravenously once every three weeks.

Regarding safety, no dose-limiting toxicities were observed even in the highest dose group (195 mg), and the maximum tolerated dose was not reached. The most common treatment-related adverse event was pruritus (3 patients), and one patient experienced a grade 3 or higher adverse event of erythematous rash.

Kim Hoon-taek, CEO of TiUM Bio, said, "We have achieved an outstanding disease control rate of over 66% in the ongoing Phase 1b trial targeting patients with advanced solid tumors," adding, "Especially, more encouraging responses were observed in patients receiving the recommended Phase 2 dose of 195 mg, raising expectations for TU2218."

In February, TiUM Bio received approval for a Phase 2a combination therapy clinical trial of TU2218 involving up to 116 patients with cholangiocarcinoma, head and neck cancer, and colorectal cancer. The selected cancer types are those with high expression of TGF-ß, a major inhibitory factor of TU2218, and low response rates of around 20% to Keytruda.