Welcome back to the D.I.S.C.O., FDA’s Drug Information Soundcast in Clinical Oncology, Burst Edition, brought to you by FDA’s Division of Drug Information in partnership with FDA’s Oncology Center of Excellence. Today we’ll provide a quick update on a recent FDA cancer drug approval.
On October 24, 2023, the FDA approved ivosidenib (brand name Tibsovo) for adult patients with relapsed or refractory myelodysplastic syndromes with a susceptible isocitrate dehydrogenase-1 mutation, as detected by an FDA-approved test. The FDA also approved the Abbott RealTime IDH1 Assay as a companion diagnostic device to select patients for ivosidenib.
Approval was based on trial AG120-C-001, an open-label, single-arm, multicenter trial of 18 adult patients with relapsed or refractory myelodysplastic syndromes with an isocitrate dehydrogenase-1 mutation. Isocitrate dehydrogenase-1 mutations were detected in peripheral blood or bone marrow by a local or central diagnostic test and confirmed retrospectively by the Abbott RealTime IDH1 Assay.
Ivosidenib was administered orally at a starting dose of 500 mg daily continuous for 28-day cycles until disease progression, unacceptable toxicity, or hematopoietic stem cell transplantation. The median treatment duration was 9.3 months. One patient underwent a stem cell transplantation following ivosidenib.
Efficacy was established by the rate of complete remission or partial remission (as assessed by the 2006 International Working Group response for myelodysplastic syndromes), complete remission and partial remission durations, and conversion rate from transfusion dependence to independence. All observed responses were complete remissions. The complete remission rate was 38.9%. The median time-to-complete remission was 1.9 months and the median complete remission duration was not estimable. Among 9 patients dependent on red blood cell and/or platelet transfusions at baseline, 6 became red blood cell and platelet transfusion independent during any 56-day post-baseline period. Of the 9 patients independent of both red blood cell and platelet transfusions at baseline, 7 remained transfusion independent during any 56-day post-baseline period.
The prescribing information contains a Boxed Warning alerting health care professionals and patients about the risk of differentiation syndrome which may be life-threatening or fatal. This review used the Assessment Aid, a voluntary submission from the applicant to facilitate the FDA’s assessment.
Health care professionals should report serious adverse events to FDA’s MedWatch Reporting Program at www.fda.gov/medwatch.
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