New Phase III data falls short on OS but supports sNDA filing for Agios' Tibsovo in 1st-qtr 2021

US cancer metabolism specialist Agios Pharmaceuticals (Nasdaq: AGIO) has reported a full analysis of the final data, including mature overall survival (OS) results, from its global Phase III ClarIDHy trial of Tibsovo (ivosidenib tablets) in patients with previously treated isocitrate dehydrogenase 1 (IDH1) mutated cholangiocarcinoma, a rare cancer of the bile ducts.

Data from the study were featured in an oral presentation at the American Society of Clinical Oncology Gastrointestinal Cancers Symposium (ASCO-GI), which is being held virtually January 15-17, 2021.

The final analysis showed an improvement in the secondary endpoint of OS favoring patients randomized to Tibsovo compared to those randomized to placebo; however, statistical significance was not reached. The median OS for patients randomized to Tibsovo was 10.3 months compared to 7.5 months for patients randomized to placebo (hazard ratio [HR]=0.79; 95% CI [0.56–1.12], 1-sided p=0.093). The protocol specified that patients randomized to placebo could cross over to Tibsovo at the time of disease progression, and a high proportion of patients in the placebo arm (70.5%) crossed over to Tibsovo.