Dr. Abou-Alfa on the Results of the ClarIDHy Trial in Advanced Cholangiocarcinoma

Ghassan K. Abou-Alfa, MD, medical oncologist, Memorial Sloan Kettering Cancer Center, discusses the results of the phase III ClarIDHy trial in advanced cholangiocarcinoma.

In the ClarIDHy study, 185 patients with IDH1-mutant cholangiocarcinoma were randomized 2:1 to receive either ivosidenib (Tibsovo) or placebo. Patients could not have received more than 2 prior lines of therapy in order to be eligible for enrollment. Crossover from the placebo arm to ivosidenib was allowed if patients experienced radiographic progression. Progression-free survival (PFS) by blinded independent review served as the primary endpoint of the trial.

Data presented at the 2019 ESMO Congress showed that the median PFS was 2.7 months versus 1.4 months, for ivosidenib and placebo, respectively (HR, 0.37; 95% CI, 0.25-0.54; P <.001). Notably, the 6- and 12-month PFS rates were 32% and 21.9% in the ivosidenib arm. These rates were not evaluable in the placebo arm because all patients had already crossed over to the ivosidenib arm at the time of assessment, explains Abou-Alfa. Finally, the overall survival was 10.8 months in the ivosidenib arm versus 6 months in the placebo arm, after accounting for crossover (HR, 0.46; P =.0008).