FDA Approves Tibsovo (Ivosidenib) for Acute Myeloid Leukemia (AML)

The US Food and Drug Administration (FDA) has approved the targeted therapy drug Tibsovo (ivosidenib) to treat some adults with a certain type of acute myeloid leukemia (AML). It’s for people with AML that has come back after previous treatment, or that did not get better during treatment. It’s the first drug approved to treat AML patients with a specific mutation in the IDH1 gene.

AML is a type of cancer that starts in the bone marrow. If not treated, it quickly moves into the blood and sometimes into other parts of the body. In some people with AML, the leukemia cells have a mutation in the IDH1 gene. This gene helps the cells make a protein that helps them grow. Tibsovo works by blocking the IDH1 protein on leukemia cells.

Last year the FDA approved Idhifa (enasidenib) for people with AML who have a mutation in the IDH2 gene. The FDA approved a test for the gene mutations along with both drug approvals.

The FDA based its approval on a clinical trial of 174 people with AML with an IDH1 mutation, and whose cancer had come back after treatment or had never responded to previous treatment. After an average follow-up time of 8.3 months, 32.8% of patients who were given Tibsovo had either no evidence of cancer and full recovery of blood counts, or no evidence of cancer and a partial recovery of blood counts. The improvement lasted for an average 8.2 months.

Among the 110 patients who needed blood or platelet transfusions when the study started, 37% were able to go at least 56 days with no transfusion after being treated with Tibsovo.

The FDA evaluated Tibsovo through its fast track and priority review programs, which are meant to speed up the availability of drugs to treat serious diseases. Tibsovo also received orphan product designation, which provides incentives to the drug’s developers because it is intended to treat a rare disease.

Tibsovo is a tablet taken by mouth. The most common side effects are fatigue, increase in white blood cells, joint pain, diarrhea, shortness of breath, swelling in the arms or legs, nausea, pain or sores in the mouth or throat, irregular heartbeat, rash, fever, cough, and constipation. Women who are breastfeeding should not take Tibsovo because it may cause harm to a newborn baby.

A serious possible side effect of Tibsovo is differentiation syndrome, which can be fatal if not treated. Signs and symptoms of differentiation syndrome include fever, difficulty breathing, acute respiratory distress, inflammation in the lungs, fluid around the lungs or heart, rapid weight gain, swelling, or dysfunction of the liver, kidney, or other organ.

Other serious possible side effects include QT prolongation, which is a disruption in the electrical activity of the heart, and Guillain-Barre syndrome, which is a neurological disorder.

Tibsovo is marketed by Agios Pharmaceuticals, Inc, and the RealTime IDH1 Assay genetic test is marketed by Abbott Laboratories.