Rigel Announces Publication of Data on REZLIDHIA® (Olutasidenib) in Post-Venetoclax Patients with Mutant IDH1 Acute Myeloid Leukemia (AML)

SOUTH SAN FRANCISCO, Calif. — Rigel Pharmaceuticals, Inc. (Nasdaq: RIGL) today announced a peer-reviewed publication in Leukemia & Lymphoma on data from an analysis of the Phase 2 study evaluating REZLIDHIA® (olutasidenib), a potent, selective, oral, small-molecule inhibitor of mutant isocitrate dehydrogenase-1 (mIDH1), in patients with mIDH1 acute myeloid leukemia (AML) who were relapsed/refractory (R/R) to prior venetoclax-based regimens.

“Venetoclax in combination with a hypomethylating agent is currently standard treatment for patients with newly diagnosed AML who are unfit for intensive chemotherapy, including those with mIDH1. When this therapy fails, patients historically have had limited treatment options and poor prognoses,” said Jorge E. Cortes, M.D., Director, Georgia Cancer Center, Cecil F. Whitaker Jr., GRA Eminent Scholar Chair in Cancer, and Phase 2 trial investigator. “The findings from these analyses suggest that REZLIDHIA may provide an effective treatment for patients with AML following failure of venetoclax combination therapy. REZLIDHIA induced durable remissions consistent with those observed in the pivotal trial and had a favorable tolerability profile in this challenging to treat patient population, representing a valuable treatment option.”

“These data support REZLIDHIA’s efficacy and well-characterized safety profile in patients with mIDH1 R/R AML who had previously been treated with venetoclax combination regimens,” said Raul Rodriguez, Rigel’s president and CEO. “These analyses are important because they provide valuable insights into the potential benefit of REZLIDHIA in different segments of the mIDH1 R/R AML patient population.”

Key points from the paper are summarized below:

  • Olutasidenib alone or in combination with azacitidine demonstrated potential efficacy in patients with AML following failure of venetoclax combination therapy
  • Of the 18 patients with prior venetoclax treatment, 10 were relapsed, 6 were refractory, and 2 had complete remission with incomplete hematologic recovery (CRi) to a venetoclax combination
  • Of the 16 R/R patients, 7 (43.8%) achieved a composite complete remission (CRc), 4 (25%) achieved complete remission (CR), and 1 (6.3%) achieved CR with partial hematologic recovery (CRh). Both patients with CRi at study entry achieved CR
  • Median time to CRc was 1.9 months (range 1-2.8). As of the data cut-off (June 18, 2021), median duration of CRc was not reached (range, 1.2-NR, ongoing at 30.4+ months)
  • Red blood cell and platelet transfusion independence was achieved in 2/12 (17%) and 2/7 (29%) transfusion-dependent R/R patients at baseline, respectively
  • Safety was consistent with the overall profile of olutasidenib

The paper, titled “Olutasidenib in post-venetoclax patients with mutant isocitrate dehydrogenase 1 (mIDH1) acute myeloid leukemia (AML),” was published online in Leukemia & Lymphoma and can be accessed here.


About AML
Acute myeloid leukemia (AML) is a rapidly progressing cancer of the blood and bone marrow that affects myeloid cells, which normally develop into various types of mature blood cells. AML occurs primarily in adults and accounts for about 1 percent of all adult cancers. The American Cancer Society estimates that there will be about 20,800 new cases in the United States, most in adults, in 2024.

Relapsed AML affects about half of all patients who, following treatment and remission, experience a return of leukemia cells in the bone marrow. Refractory AML, which affects between 10 and 40 percent of newly diagnosed patients, occurs when a patient fails to achieve remission even after intensive treatment. 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.


About Rigel
Rigel Pharmaceuticals, Inc. (Nasdaq: RIGL) is a biotechnology company dedicated to discovering, developing and providing novel therapies that significantly improve the lives of patients with hematologic disorders and cancer. Founded in 1996, Rigel is based in South San Francisco, California.


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