FDA approves new therapy for myelodysplastic syndromes

The US Food and Drug Administration (FDA) has approved a new therapy for adults with relapsed or refractory (R/R) myelodysplastic syndromes (MDS) with an isocitrate dehydrogenase-1 (IDH1) mutation, a rare type of blood cancer. The small molecule treatment Tibsovo (ivosidenib) is the first targeted therapy approved for this indication.

Clinical evidence for Tibsovo

This new US approval for Tibsovo was based on data from an open-label, single-arm, multi-centre Phase I study.

In the trial, the effectiveness of this new indication was evaluated in 18 adult patients with relapsed or refractory MDS with an IDH1 mutation. Tibsovo was administered orally at a starting dose of 500mg daily continuous for 28-day cycles until disease progression, development of unacceptable toxicity or undergoing bone marrow transplantation, according to the FDA. 

The observed complete remission or partial remission rate in this patient group was 39 percent. Median duration of complete remission reportedly ranged from 1.9 to 80.8 months. For patients who achieved a complete remission, the median time to complete remission was 1.9 months. FDA stated that among the nine patients who required transfusions of blood or platelets due to MDS at the beginning of the study, 67 percent) no longer required transfusions post-treatment with Tibsovo. 

Regulatory authorisation of Tibsovo was granted to the firm Servier Pharmaceuticals LLC.

FDA’s approval “represents an important treatment advancement for rare blood cancers” according to Dr Richard Pazdur, Director of the FDA’s Oncology Center of Excellence and Acting Director of the Office of Oncologic Diseases in the FDA’s Center for Drug Evaluation and Research.

Earlier this year in March 2023, the Committee for Medicinal Products for Human Use (CHMP) adopted a positive opinion for Tibsovo (ivosidenib) to treat newly diagnosed acute myeloid leukaemia (AML) and locally advanced or metastatic cholangiocarcinoma, a bile duct cancer. Additionally, the committee also adopted a positive opinion for its duplicate Tidhesco (ivosidenib) for newly diagnosed acute myeloid leukaemia.