With fresh FDA nod, Servier branches targeted drug Tibsovo into bile duct cancer

The FDA has greenlighted Servier's Tibsovo as the first targeted drug for previously treated cholangiocarcinoma with an IDH1 mutation. (Servier)

As Servier moves targeted cancer drug Tibsovo closer to earlier treatment of acute myeloid leukemia—and eyes a potential competitor, too—the French drugmaker has picked up a smaller use along the way.

The FDA has greenlighted Tibsovo for previously treated cholangiocarcinoma with an IDH1 mutation, making the drug the first targeted therapy for those patients, Servier said Wednesday.

Cholangiocarcinoma is a rare cancer of the bile ducts with estimated annual diagnoses of about 8,000 people in the U.S. About 20% bear IDH1 mutations, the company said.

Servier won FDA backing with data from the phase 3 ClarIDHy trial. Tibsovo cut the risk of disease progression or death by 63% over placebo in previously treated IDH-mutated patients in the study. Twenty-two percent of patients who got the IDH inhibitor were still alive without tumor progression after one year of treatment, while none in the placebo group could say that.

Tibsovo also appeared to help patients live longer, although the improvement wasn’t statistically significant. Patients who received Tibsovo lived a median 10.3 months, versus 7.5 months for those on the placebo arm. But as Servier pointed out, 70.5% of placebo patients went on to receive Tibsovo after disease progression. That large number of patient crossover likely ratcheted up the overall survival numbers for placebo.

RELATED: Servier scores a win in bid to expand Tibsovo in acute myeloid leukemia—and reach Europe where Agios failed

The new go-ahead comes just weeks after Servier touted a phase 3 win for Tibsovo in previously untreated IDH1-mutated acute myeloid leukemia (AML). It found that adding Tibsovo to Bristol Myers Squibb’s Vidaza could extend the time to treatment failure, tumor relapse or death.

With its original FDA nod in 2018 under former owner Agios Pharmaceuticals, Tibsovo has been used to treat relapsed or treatment-resistant IDH-mutated AML or newly diagnosed patients who are at least 75 years old or who aren’t eligible for intensive chemotherapy.

Servier is now working to move Tibsovo into that larger front-line AML setting—and potentially persuade the European Medicines Agency to reverse a previous rejection, which cited a lack of controlled data.

RELATED: Forma Therapeutics' IDH1 blocker banishes leukemia in 33% of patients

Meanwhile, Forma Therapeutics is preparing to file its IDH1 inhibitor, olutasidenib, with the FDA for previously treated AML, and it’s looking for a commercial partner. In a phase 2 trial in those patients, olutasidenib recorded a 33.3% rate of complete remission or complete remission with partial hematologic recovery.

Olutasidenib’s tumor response showing was very similar to Tibsovo’s 32.8% rate in its own phase 1/2 trial. But the duration of response appears longer for the Forma drug at a median of 13.8 months, versus 8.2 months for Tibsovo.