Olutasidenib (Rezlidhia) — Clinical FAQs

Question 1

What is Olutasidenib FDA-approved to treat?

Accepted Answer

Olutasidenib is FDA-approved for the following oncology indications: 1. Relapsed or refractory acute myeloid leukemia (AML) with a susceptible IDH1 mutation as detected by an FDA-approved companion diagnostic test — adults (FDA approved December 2022; based on Study 2102-HEM-101).

Question 2

How does Olutasidenib work (mechanism of action)?

Accepted Answer

Olutasidenib is an orally bioavailable, selective, potent inhibitor of mutant isocitrate dehydrogenase-1 (IDH1) harboring R132 point mutations (R132H, R132C, R132G, R132S, and R132L variants). Wild-type IDH1 catalyzes oxidative decarboxylation of isocitrate to α-ketoglutarate (α-KG) in the TCA cycle. The IDH1 R132 neomorphic mutation confers a gain-of-function activity, converting α-KG to the oncometabolite 2-hydroxyglutarate (2-HG) at the expense of NADPH. 2-HG accumulates to millimolar concentrations and competitively inhibits α-KG-dependent dioxygenases — including TET2 (a DNA demethylase) and Jumonji-domain histone demethylases — inducing a hypermethylation phenotype that blocks hematopoietic differentiation and drives leukemogenesis. Olutasidenib binds the allosteric site at the IDH1 dimer interface, inhibiting mutant enzyme activity, depleting intracellular 2-HG, and restoring α-KG-dependent epigenetic regulation, permitting terminal myeloid differentiation of IDH1-mutant leukemic blasts.

Question 3

How is Olutasidenib administered?

Accepted Answer

Olutasidenib is administered Oral (PO). Olutasidenib 150 mg PO twice daily (every 12 hours), with or without food.

Question 4

What are the most common side effects of Olutasidenib?

Accepted Answer

The most commonly reported side effects of Olutasidenib (≥10% incidence) include: Nausea (44%), Fatigue (36%), Arthralgia / joint pain (35%), Constipation (32%), Dyspnea (31%) and others (19 total). Consult your oncologist for complete prescribing information.

Question 5

Does Olutasidenib have a black box warning?

Accepted Answer

Yes. Olutasidenib carries FDA black box warning(s) regarding: 1. Differentiation syndrome: Olutasidenib can cause differentiation syndrome (DS), which is potentially fatal if not recognized and treated promptly. DS results from rapid maturation of IDH1-mutant leukemic blasts and is characterized by fever, dyspnea, hypoxia, pulmonary infiltrates, pleural or pericardial effusions, rapid weight gain, peripheral edema, rash, renal dysfunction, and lymphadenopathy. In clinical trials, DS occurred in 17% of patients (grade ≥3 in 8%); median onset was 13 days from initiation. If DS is suspected, immediately initiate dexamethasone 10 mg IV every 12 hours and hemodynamic monitoring; add hydroxyurea if WBC ≥30,000/mm³. Interrupt olutasidenib only for severe, unresponsive pulmonary compromise. Do not delay corticosteroids pending confirmation — DS can be fatal.

Question 6

Is Olutasidenib safe during pregnancy?

Accepted Answer

Olutasidenib pregnancy safety: Causes fetal harm (no traditional FDA letter category under current labeling). Olutasidenib is expected to cause embryo-fetal toxicity based on mechanism of action — IDH1 inhibition disrupts α-KG-dependent dioxygenases critical for epigenetic regulation during fetal development. Females of reproductive potential must use effective non-hormonal contraception during treatment and for at least 30 days after the last dose. Males with female partners of reproductive potential must use contraception during therapy and for 90 days after the last dose. Breastfeeding is contraindicated during treatment and for 2 weeks after the last dose.. Oncologists should review the complete prescribing information and discuss reproductive risks with patients before initiating therapy.

Olutasidenib — Drug Monograph

Mechanism of Action

FDA Indications

Common Side Effects

Clinical Pearl

Related Therapies & Mechanisms