IDH1 and cholangiocarcinoma: Furthermore, since the ClarIDHy study was a placebo‐controlled study and no direct comparison between ivosidenib and second‐line chemotherapy is available, we conducted a pre‐planned comparison between patients treated with ivosidenib as second‐line treatment in our cohort and a previously published cohort of patients affected by advanced IDH1 mutant CCA treated with second‐line FOLFOX/CAPOX.