In July 2018, the FDA approved Tibsovo (ivo-sidenib; from Agios Pharmaceuticals), the first IDH1 inhibitor, for the treatment of adults with relapsed (returning) or refractory (not responding to treatment) acute myeloid leukemia (AML) and a susceptible IDH1 genetic mutation. On the same day, the FDA approved the RealTime IDH1 test, which is designed to identify the IDH1 mutation. Tibsovo should be used in patients after they had the RealTime IDH1 genetic test to confirm that they have that mutation.
“Tibsovo is a targeted therapy that fills an unmet need for patients with relapsed or refractory AML who have an IDH1 mutation,” said Richard Pazdur, MD, Director of the FDA’s Oncology Center of Excellence. “The use of Tibsovo is associated with a complete remission in some patients and a reduction in the need for both red cell and platelet transfusions.”
This approval was based on a clinical trial of 174 adults with relapsed or refractory AML and a confirmed IDH1 mutation. In about 32% of the patients, the cancer was in complete remission after receiving Tibsovo. It took an average of 2 months to respond to this treatment, and the remission lasted an average of 8.2 months.
Among the most common side effects with Tibsovo were fatigue, increase in white blood cells, joint inflammation/pain, diarrhea, shortness of breath, nausea, mucositis, fever, cough, and constipation.