In May 2022, the FDA approved oral Tibsovo (ivosidenib; from Servier Pharmaceuticals), for use with intravenous or subcutaneous azacitidine, for the treatment of newly diagnosed acute myeloid leukemia (AML) and a susceptible IDH1 mutation, as detected by an FDA-approved test, in patients aged 75 years or older, or patients with other medical conditions that prevent the use of initial intensive chemotherapy.
This new indication was approved based on a clinical trial of 146 patients with newly diagnosed AML and IDH1 mutation. The patients were divided into 2 groups: 72 patients received Tibsovo plus azacitidine and 74 patients received placebo plus azacytidine until disease progression, unacceptable side effects, or undergoing stem-cell transplant.
The average overall survival was 2 years in the Tibsovo and azacitidine group compared with only 7.9 months in the placebo plus azacytidine group. After 24 weeks, almost half (47%) of the patients who received Tibsovo plus azacitidine had a complete response (no sign of cancer) to treatment compared with only 15% of those who received placebo plus azacitidine. The average length of complete remission was not reached in the Tibsovo arm (meaning patients are still responding to the treatment) compared with 11.2 months in the placebo arm.
The most common side effects reported with Tibsovo plus azacitidine or alone are diarrhea, fatigue, edema, nausea, vomiting, decreased appetite, leukocytosis, arthralgia, dyspnea, abdominal pain, mucositis, rash, differentiation syndrome (which may be life-threatening), and myalgia.
Treatment with Tibsovo plus azacitidine is recommended for a minimum of 6 months in patients who can tolerate the treatment or those whose cancer does not progress, to allow time for appropriate clinical response.