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Tibsovo
Published
Product name
Tibsovo
Active ingredient
Ivosidenib
Submission type
New Chemical Entity
Decision
Approved
Decision date
Registration date
What this medicine was approved for
Acute myeloid leukaemia
Tibsovo is indicated for the treatment of acute myeloid leukaemia (AML) that carries an IDH1 R132 mutation:
- as monotherapy, or in combination with azacitidine, in newly diagnosedpatients who are not eligible to receive intensive induction chemotherapy; or
- as monotherapy in patients whose AML is relapsed and/or refractory to priortherapy.
How this medicine works
Ivosidenib is a small molecule inhibitor of certain mutant isocitrate dehydrogenase 1 (IDH1) enzymes. Through a gain of neomorphic function, the mutant IDH1 converts alpha-ketoglutarate (α-KG) to 2- hydroxyglutarate (2-HG). As 2-HG competitively inhibits α-KG-dependent enzymes, including histone and DNA demethylases, its accumulation leads to widespread epigenetic dysregulation. Ivosidenib inhibited selected IDH1 mutants (R132C, R132L, R132G, R132H and R132S) at much lower concentrations than wild-type IDH1 in vitro. Inhibition of the mutant IDH1 enzyme by ivosidenib led to decreased 2-HG levels and induced myeloid differentiation in vitro and in vivo in mouse xenograft models of IDH1-mutated AML. In blood samples from patients with AML with mutated IDH1, ivosidenib decreased 2-HG levels, reduced blast counts, and increased percentages of mature myeloid cells.
Why the TGA approved or did not approve this medicine
The decision was based on quality (chemistry and manufacturing), nonclinical (pharmacology and toxicology), clinical (pharmacology, safety and efficacy) and risk management plan information submitted by the sponsor. The benefit-risk profile of Tibsovo was considered favourable for the therapeutic use approved.