New IDH1 Inhibitor Wins FDA Approval for Acute Myeloid Leukemia

— Olutasidenib led to a 35% response rate in a study of adults with previously treated AML

MedicalToday
FDA APPROVED olutasidenib (Rezlidhia) over a computer rendering of acute myeloid leukemia cells.

The FDA approved the IDH1 inhibitor olutasidenib (Rezlidhia) for relapsed or refractory (AML).

The approved indication stipulates use of olutasidenib in relapsed/refractory AML associated with an IDH1 mutation. The FDA also approved the Abbott RealTime IDH1 Assay as a companion diagnostic to select patients for olutasidenib.

"Rezlidhia is a novel, non-intensive monotherapy treatment in the relapsed/refractory AML setting demonstrating a CR+CRh [complete response with or without hematologic recovery] rate of 35% in patients, with over 90% of those responders in complete remission," Jorge E. Cortes, MD, of Georgia Cancer Center in Atlanta, said in a from Rigel Pharmaceuticals. "The 25.9 months median duration of CR+CRh is a clinically meaningful improvement for AML patients and appears to be longer than currently available treatment options."

Patients with relapsed/refractory, IDH1-mutant AML typically have a poor prognosis and therapeutic options are limited, said Cortes. "Rezlidhia may provide an effective, new treatment option with a well-characterized safety profile."

Support for the approval came from a involving 153 adults with relapsed/refractory IDH1-mutant AML. The 35% objective response rate included CR in 32% of patients. The median time to CR/CRh was 1.9 months. The duration of response was an estimate, as the upper limit of the 95% confidence intervals had yet to be reached at last data analysis.

Following treatment with olutasidenib, 16 patients (11%) underwent hematopoietic stem-cell transplantation.

The most common adverse reactions (≥20%) were nausea, fatigue/malaise, arthralgia, constipation, leukocytosis, dyspnea, fever, rash, mucositis, diarrhea, and transaminitis. The prescribing information contains a boxed warning about a risk of potentially fatal differentiation syndrome.

In a licensing agreement with Forma Therapeutics, Rigel has exclusive rights for the launch and commercialization of olutasidenib in the U.S.

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    Charles Bankhead is senior editor for oncology and also covers urology, dermatology, and ophthalmology. He joined in 2007.