The FDA approved Agios Pharmaceuticals’ Tibsovo (ivosidenib) as a first-line treatment for elderly patients with acute myeloid leukemia.

Patients must be at least 75 years old and test positive for a susceptible IDH1 mutation or they must have other diseases that would keep them from undergoing intensive chemotherapy, the agency said.

The approval comes after Agios handed up results from a clinical trial of 28 elderly leukemia patients. Researchers gave the patients a single dose of 500 mg of Tibsovo daily until the disease either got worse, the treatment became too toxic or—in two cases—patients underwent stem cell transplants. Twelve of the patients were able to go without transfusions for at least eight weeks, the data showed.

Tibsovo is already approved for relapsed or refractory acute myeloid leukemia patients who have the IDH1 mutation.