General Information

Tibsovo (ivosidenib) is an isocitrate dehydrogenase-1 (IDH1) inhibitor. Genetically mutated IDH1 is associated with acute myeloid leukemia.

Tibsovo is specifically indicated for the treatment of adult patients with relapsed or refractory acute myeloid leukemia (AML) with a susceptible isocitrate dehydrogenase-1 (IDH1) mutation as detected by an FDA-approved test.

Tibsovo is supplied as a tablet for oral administration. The recommended dose is 500 mg taken orally once daily until disease progression or unacceptable toxicity. For patients without disease progression or unacceptable toxicity, treat for a minimum of 6 months to allow time for clinical response. Administer Tibsovo with or without food. Do not administer Tibsovo with a high-fat meal because of an increase in ivosidenib concentration. Do not split or crush tablets. Administer tablets orally about the same time each day. If a dose of Tibsovo is vomited, do not administer a replacement dose; wait until the next scheduled dose is due. If a dose is missed or not taken at the usual time, administer the dose as soon as possible and at least 12 hours prior to the next scheduled dose. Return to the normal schedule the following day. Do not administer 2 doses within 12 hours.  

Clinical Results

FDA Approval

The FDA approval of Tibsovo was based on a single-arm trial of 174 adult patients with relapsed or refractory AML with an IDH1 mutation. Tibsovo was given orally at a starting dose of 500 mg daily until disease progression, development of unacceptable toxicity, or undergoing hematopoietic stem cell transplantation. The trial measured the percentage of patients with no evidence of disease and full recovery of blood counts after treatment (complete remission or CR), as well as patients with no evidence of disease and partial recovery of blood counts after treatment (complete remission with partial hematologic recovery or CRh). With a median follow-up of 8.3 months, 32.8% of patients experienced a CR or CRh that lasted a median 8.2 months. Of the 110 patients who required transfusions of blood or platelets due to AML at the start of the study, 37% went at least 56 days without requiring a transfusion after treatment with Tibsovo. 

Side Effects

Adverse effects associated with the use of Tibsovo may include, but are not limited to, the following:

fatigue

leukocytosis

arthralgia

diarrhea

dyspnea

edema

nausea

mucositis

electrocardiogram QT prolonged

rash

pyrexia

cough

constipation

The Tibsovo drug label comes with the following Black Box Warning:

Patients treated with Tibsovo have experienced symptoms of differentiation syndrome, which can be fatal if not treated. Symptoms may include fever, dyspnea, hypoxia, pulmonary infiltrates, pleural or pericardial effusions, rapid weight gain or peripheral edema, hypotension, and hepatic, renal, or multi-organ dysfunction. If differentiation syndrome is suspected, initiate corticosteroid therapy and hemodynamic monitoring until symptom resolution.

Mechanism of Action

Tibsovo (ivosidenib) is an isocitrate dehydrogenase-1 inhibitor that works by decreasing abnormal production of the oncometabolite 2-hydroxyglutarate (2-HG), leading to differentiation of malignant cells.

Additional Information

For additional information regarding Tibsovo or acute myeloid leukemia with a susceptible IDH1 mutation, please visit https://www.tibsovo.com/