FDA D.I.S.C.O. Burst Edition: FDA approval of Tibsovo (ivosidenib) for patients with relapsed or refractory myelodysplastic syndromes with a susceptible isocitrate dehydrogenase-1 mutation

Regulatory approval: On Oct 24, 2023, the FDA approved ivosidenib (Tibsovo) for adult patients with relapsed or refractory myelodysplastic syndromes (MDS) with a susceptible IDH1 mutation detected by an FDA-approved test. The Abbott RealTime IDH1 Assay was also approved as a companion diagnostic. Approval was based on the single-arm AG120-C-001 trial (n=18), with a complete remission rate of 38.9%. The label includes a Boxed Warning for differentiation syndrome.

FDA approval (Oct 24, 2023): ivosidenib for IDH1-mutated relapsed/refractory MDS

The FDA approved ivosidenib (Tibsovo) on October 24, 2023 for adult patients with relapsed or refractory myelodysplastic syndromes (MDS) with a susceptible isocitrate dehydrogenase-1 (IDH1) mutation, as detected by an FDA-approved test. The FDA also approved the Abbott RealTime IDH1 Assay as a companion diagnostic to select patients for ivosidenib.

Supporting evidence

Approval was based on AG120-C-001, an open-label, single-arm, multicenter trial in 18 adults with relapsed/refractory IDH1-mutated MDS. IDH1 mutations were identified by local or central testing (peripheral blood or bone marrow) and confirmed retrospectively by the Abbott RealTime IDH1 Assay.

Patients received ivosidenib 500 mg orally once daily, continuous 28-day cycles until progression, unacceptable toxicity, or hematopoietic stem cell transplantation. Median treatment duration was 9.3 months; 1 patient proceeded to transplantation.

Efficacy highlights (per 2006 IWG criteria)

  • All observed responses were complete remissions (CR)
  • CR rate: 38.9%
  • Median time to CR: 1.9 months
  • Median CR duration: not estimable
  • Among 9 transfusion-dependent patients at baseline, 6 became RBC and platelet transfusion independent during any 56-day post-baseline period.

Safety note

Prescribing information includes a Boxed Warning for differentiation syndrome, which may be life-threatening or fatal.

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