FDA Approves Servier's Tibsovo as First Targeted Therapy for Rare Blood Cancer: MDS

The FDA has approved Servier's Tibsovo, marking a pivotal moment as the first and only targeted therapy for adults with IDH1-mutated relapsed or refractory myelodysplastic syndromes (MDS). This landmark approval, Tibsovo's fifth indication in IDH1-mutated cancers, offers new hope for patients within this molecularly defined subset, previously without such a specific treatment option.

The U.S. Food and Drug Administration (FDA) has approved Tibsovo (ivosidenib) for treating adults with relapsed or refractory myelodysplastic syndromes (MDS) with an IDH1 mutation. The decision followed a study showing a 39% remission rate among treated patients. The Abbott RealTime IDH1 Assay was also approved for detecting suitable patients. 

Myelodysplastic syndromes are uncommon blood cancers resulting from mutations in bone marrow progenitor cells, which lead to a decline in healthy blood cells. Current estimates suggest that between 60,000 to 170,000 people in the U.S. are living with MDS, with a global incidence of roughly 87,000 new cases each year. Notably, about 3.6 percent of MDS patients possess an IDH1 mutation.

The approval came after an extensive open-label, multicenter study of 18 adult patients with relapsed or refractory MDS and an IDH1 mutation. The results showed a complete or partial remission rate of 39% among these patients, with a median duration of complete remission spanning from 1.9 to 80.8 months. Importantly, out of the nine patients who initially required blood or platelet transfusions due to MDS, six no longer needed them post-Tibsovo treatment.

Alongside Tibsovo's approval, the FDA also sanctioned the Abbott RealTime IDH1 Assay as a complementary diagnostic tool for identifying patients with the IDH1 mutation. This assay has previously been approved for detecting AML patients with the IDH1 mutation eligible for treatment with Tibsovo or Rezlidhia (olutasidenib).

Richard Pazdur, M.D., the director of the FDA's Oncology Center of Excellence and the acting director of the Office of Oncologic Diseases, emphasized the significance of this approval:  

"Today's approval represents an important treatment advancement for rare blood cancers, and more specifically, patients with relapsed or refractory MDS who have an IDH1 mutation. Through the FDA's Oncology Center of Excellence Rare Cancers Program, we remain committed to promoting scientific innovation and advancing the development of safe and effective novel therapies to treat patients with rare cancers."

Potential users of Tibsovo should be aware of the therapy's potential side effects, which include diarrhea, nausea, joint pain, fatigue, and rash. Additionally, the medication might cause QTc prolongation, a condition leading to abnormal heart rhythms. The FDA has also issued a boxed warning about differentiation syndrome, a possibly fatal adverse reaction. Early symptoms include fever, difficulty breathing, and swelling. Immediate treatment with corticosteroids is recommended upon the detection of initial symptoms.

“Servier is proud to lead the way in mutant IDH inhibition through continued innovations that support patients living with difficult and hard-to-treat cancers,” said Arjun Prasad, Head of Commercial, Servier Pharmaceuticals. “As the first and only targeted therapy available for patients with IDH1-mutated relapsed or refractory myelodysplastic syndromes, today’s FDA approval for TIBSOVO reinforces our commitment to deliver significant advances in areas of high unmet need and bring the right treatment, to the right patient, at the right time.”

Servier Pharmaceuticals LLC received approval for Tibsovo, while Abbott Laboratories obtained approval for the RealTime IDH1 Assay. Tibsovo has also garnered Priority Review, Breakthrough Therapy, and Orphan Drug designations from the FDA. The agency's Priority Review mechanism aims for a swift decision-making process, targeting action on an application within six months if the drug under review promises significant advancements in safety or efficacy.