FDA Grants Priority Review for Tibsovo sNDA for Myelodysplastic Syndromes

The FDA has granted priority review for the Servier’s supplemental new drug application (sNDA) for Tibsovo (ivosidenib) to treat patients with relapsed or refractory (R/R) myelodysplastic syndromes (MDS). It would be indicated to treat patients with isocitrate dehydrogenase 1 (IDH1) mutations. If approved, it would be the first approved targeted therapy for MDS patients with an IDH1 mutation. With priority review, the FDA provides a decision on an application within six months.

Myelodysplastic syndromes are disorders in which stem cells do not mature into healthy blood cells. In the United States, about 16,000 new cases of MDS are reported each year, and one-third of these patients will eventually progress to acute myeloid leukemia (AML). About 3.6% of MDS patients have an IDH1 mutation, which has been associated with worse overall outcomes.

Tibsovo is currently approved in the United States as a monotherapy to treat adults with IDH1-mutant relapsed or refractory AML and in monotherapy or in combination with azacitidine for adults with newly diagnosed IDH1-mutant AML who are 75 years old or older. It has a list price of $31,687 for a supply of 60 tablets, according to Drugs.com.

Amir T. Fathi, M.D.

“While the novel use of targeted IDH inhibition has been proven across a number of difficult-to-treat cancers, there continues to be a significant unmet need for MDS patients within this molecularly defined subset, especially for those who experience disease progression,” Amir T. Fathi, M.D., program director, Center for Leukemia at Massachusetts General Hospital and associate professor of Medicine at Harvard Medical School, said in a press release.

The submission is based data from a phase 1 open-label trial of 18 patients in the efficacy analysis that showed Tibsovo resulted in a complete remission rate of 38.9% and objective response rate of 83.3%. Additionally, of the nine patients who were transfusion dependent with red blood cells or platelets at baseline, six became independent of transfusions during the post-baseline period. There were no new safety signals identified in this study.

Results were released at the European Hematology Association (EHA) 2023 Annual Congress.

Servier also recently data from a phase 3 trial of Tibsovo as first-line treatment of newly-diagnosed acute myeloid leukemia that were presented at the 2023 Annual Meeting of the American Society of Clinical Oncology (ASCO). In this placebo-controlled study, Tibsovo in combination with azacytidine demonstrated a three-fold improvement in median overall survival (24 months) compared with azacitidine plus placebo (7.9 months). In long-term follow-up data as of June 2022, at a median follow-up of 28.6 months, median overall survival was 29.3 months for Tibsovo in combination with azacitidine vs 7.9 months for azacitidine alone.