The US Food and Drug Administration (FDA) has approved Rigel Pharmaceuticals’ (Rigel) application for Rezlidhia (olutasidenib) in the treatment of adult patients with relapsed or refractory (R/R) acute myeloid leukaemia (AML) with a susceptible isocitrate dehydrogenase-1 (IDH1) mutation.
The company’s application was supported by data from the open-label phase 2 registrational study evaluating Rezlidhia monotherapy as a twice daily 150mg dose in 153 mIDH1 R/R AML patients, 147 of whom made up the efficacy-evaluable population.
Results demonstrated a 35% complete remission (CR) plus a complete remission with partial haematological recovery (CRh) in mIDH1 R/R AML patients, with a median duration of response of 25.9 months.
The median time to CR or CRh was 1.9 months and, of the patients who achieved the primary endpoint of CR+CRh, 92% were CR with a median duration of response of 28.1 months.
In terms of safety, the company reported Rezlidhia was well tolerated, with an adverse event profile characteristic of symptoms or conditions experienced by patients with AML undergoing treatment.
AML is a rapidly progressing cancer of the blood and bone marrow that accounts for about 1% of all adult cancers. The American Cancer Society estimates that in the US alone, there will be about 20,050 new cases, most in adults, in 2022.
Relapsed AML affects about half of all patients who, following treatment and remission, experience a return of leukaemia cells in the bone marrow. Quality of life declines for patients with each successive line of treatment for AML, and well-tolerated treatments in relapsed or refractory disease remain an unmet need, Rigel said in a statement.
The company’s president and chief executive officer, Raul Rodriguez, said: “We are delighted by the approval of Rezlidhia based on the strength of data supporting the efficacy and safety of the product. Rezlidhia provides a new and important, oral therapy option for patients who typically have a poor clinical outcome.”
Jointly developed by Rigel and Forma Therapeutics, Rezlidhia is an oral, small molecule, inhibitor of mutated IDH1 designed to bind to and inhibit mIDH1 to reduce 2-hydroxyglutarate levels and restore normal cellular differentiation of myeloid cells.
Under the terms of the agreement, which was announced by the companies in August this year, Rigel is responsible for the launch and commercialisation of Rezlidhia in the US and said it intends to work with potential partners to further develop and commercialise the product outside of the US.