Abstract
On August 25, 2021, the FDA approved ivosidenib for the treatment of adult patients with unresectable locally advanced or metastatic hepatocellular isocitrate dehydrogenase 1 (IDH1) mutated cholangiocarcinoma (CCA) as detected by an FDA-approved test with disease progression after 1 to 2 prior lines of systemic therapy for advanced disease. The approval was based on data from Study AG120-C-005 (ClarIDHy), a double-blind placebo-controlled trial that randomly allocated (2:1) patients to receive either ivosidenib or placebo. Independently assessed progression-free survival (PFS) was the primary endpoint. With a median follow-up of 6.9 months, the HR for PFS was 0.37 [95% confidence interval (CI), 0.25-0.54; P < 0.0001). Overall survival (OS) was the key secondary endpoint. At the final analysis of OS, with 70.5% of patients in the placebo arm receiving ivosidenib post disease progression, a non-statistically significant improvement in the ivosidenib arm with an HR = 0.79 (95% CI, 0.56-1.12) and median OS of 10.3 months (95% CI, 7.8-12.4) and 7.5 months (95% CI, 4.8-11.1) in the ivosidenib and placebo arms, respectively, were reported. Adverse reactions occurring in >20% of patients receiving ivosidenib were fatigue/asthenia, nausea, diarrhea, abdominal pain, ascites, vomiting, cough, and decreased appetite. Adverse reactions occurring in >20% of patients receiving placebo were fatigue/asthenia, nausea, abdominal pain, and vomiting. This is the first approval for the subset of patients with CCA harboring an IDH1 mutation.