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Idhifa
Published
Product name
Idhifa
Active ingredient
Enasidenib
Submission type
New chemical entity
Decision
Approved for provisional registration
Decision date
Registration date
What this medicine was approved for
Idhifa (enasidenib) was provisionally approved for the following therapeutic use:
This medicine has Provisional Approval in Australia for the treatment of adult patients with relapsed or refractory acute myeloid leukaemia who are ineligible for haematopoietic stem cell transplant, and who have an isocitrate dehydrogenase-2 (IDH2) mutation confirmed by a validated diagnostic test.
The decision to approve this indication has been made on the basis of preliminary clinical data from a Phase 1/2 clinical trial with a primary endpoint of overall response rate. An improvement in OS or PFS has not been established. The sponsor is required to submit further clinical data to confirm the efficacy and safety of the medicine.
The provisional registration period for the above medicine(s) is two years starting on the day specified in the ARTG certificate of registration.
How this medicine works
Enasidenib is a small molecule inhibitor of the isocitrate dehydrogenase 2 (IDH2) enzyme. Mutant IDH2 variants R140Q, R172S and R172K are selectively targeted by enasidenib, with the drug’s potency against these approximately 40 times greater than against wildtype IDH2. Such IDH2 mutations confer a gain of function, whereby the aberrant enzyme catalyses the production of the oncogenic metabolite 2-hydroxyglutarate (2-HG). 2-HG induces a block of cell differentiation by inhibiting the activity of chromatin-modifying histone and DNA demethylases. Inhibition of the IDH2 mutant variants R140Q and R172S/K by enasidenib, led to decreased 2 HG levels and induction of myeloid differentiation in vitro and in vivo in human xenograft models of IDH2-mutated acute myeloid leukaemia (AML).In patients with IDH2-mutated AML, enasidenib decreased 2-HG levels in blood, releasing the differentiation block of leukaemic cells and resulting in increased percentages of mature myeloid cells in bone marrow. Enasidenib reduced blast counts in a subset of patients and was not myelosuppressive.
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 Idhifa was considered favourable for the therapeutic use approved.
Sponsor
ARTG details
- 311541
- 311542