Rigel Pharmaceuticals, Inc. announced promising data from an analysis of the Phase 2 study evaluating REZLIDHIA® (olutasidenib), a potent, selective, oral, small-molecule inhibitor of mutant isocitrate dehydrogenase-1 (mID H1)1, in patients with mID H1 acute myeloid leukemia (AML) who were relapsed/refractory (R/R) to prior venetoclax-based regimens. The data are being presented in a poster at the EHA2023 Hybrid Congress. The poster titled ‘Olutasidenib in Post-Venetoclax Patients with Mutant ID H1 AML' examines a subset of 17 patients from the Phase 2 study of olutasidenib who had previously received venetoclax combination regimens.

Key points from the presentation are summarized below: Olutasidenib induced durable remissions in patients with mID H1 R/R AML, including those failing prior treatment with a venetoclax-based regimen; Of the 17 patients with prior venetoclax treatment, 5 were ongoing and 12 discontinued treatment as of the analysis cutoff date of June 18, 2021; The best response to olutasidenib was CR/CRh in 5/17 (29.4%), of which 4 (23.5%) were CR; In the 8 patients who previously received the combination of venetoclax and azacitadine, a standard treatment for AML patients unfit for chemotherapy, 3 (37.5%) patients achieved a CR/CRh; Time to CR/CRh was median 2.1 months and median duration of CR/CRh was over 18 months, as of the cut-off date. In the Phase 2 study, the registrational cohort enrolled 153 patients with mID H1 R/R AML who received olutasidenib monotherapy 150 mg twice daily. The primary endpoint was a composite of complete remission (CR) plus complete remission with partial hematological recovery (CRh).

The results demonstrated a rate of CR/CRh of 35%, with a duration of response of 25.9 months. On December 1, 2022, the U.S. Food and Drug Administration (FDA) approved REZLIDHIA (olutasidenib) capsules for the treatment of adult patients with R/R AML with a susceptible ID H1 mutation as detected by an FDA-approved test. REZLIDHIA became commercially available in the U.S. on December 22, 2022.

REZLIDHIA was added to the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for acute myeloid leukemia (AML) on January 13, 2023 as a recommended targeted therapy for adult patients with R/R AML with isocitrate dehydrogenase-1 (ID H1) mutation.