The feasibility of IDH1 mutation detection in plasma circulating tumor-cell DNA from patients with intrahepatic cholangiocarcinoma (CCA) was demonstrated.
At the 2020 ASCO annual meeting, Elia Aguado-Fraile, PhD, Agios Pharmaceuticals, Cambridge, Massachusetts, reported study results of a phase 3 clinical trial known as ClarIDHy. The researchers of this study wanted to determine if findings from the phase 1 ClarIDHy clinical trial that showed a benefit of circulating tumor-cell DNA in relation to response to therapy in patients with CCA would be confirmed and expanded on in the larger patient group of the phase 3 clinical trial.
The overall objective of the ClarIDHy clinical trials has been to assess the effectiveness of Tibsovo (ivosidenib), an IDH1 inhibitor, in the treatment of patients with intrahepatic CCA and IDH1 mutation.
Patients enrolled in ClarIDHy had non-resectable (cannot be removed by surgery) or metastatic (spreading) intrahepatic CCA with IDH1 mutation. Patients who received treatment with the IDH1 inhibitor ivosidenib had longer survival time without disease progression with patients who received placebo, which shows the effectiveness of ivosidenib in this patient population.
The goals of this analysis were to confirm the agreement between IDH1 mutation in plasma (circulating DNA) and tumor tissue, and to determine if circulating tumor-cell DNA would be predictive of the time of survival without disease progression. These possibilities had been supported in the results from the earlier, phase 1 clinical trial. Another goal was to determine whether the amount of circulating tumor-cell DNA correlated with the tumor response to therapy.
The investigators concluded that the feasibility of IDH1 mutation detection in plasma circulating tumor-cell DNA from patients with intrahepatic CCA was demonstrated and was highly concordant with mutation status in tumor tissue.
