Syndax gains FDA approval for novel leukemia drug

Massachusetts-based Syndax Pharmaceuticals has received approval from the Food and Drug Administration (FDA) for its novel drug, Revuforj, designed to treat a particularly aggressive form of leukemia in adults and some children. This drug, which is taken orally, is the first of its kind, belonging to a new category of medications known as menin inhibitors. It is indicated for patients aged one year or older who are dealing with relapsed or refractory acute leukemia that features a specific genetic mutation: translocations in the lysine methyltransferase 2A (KMT2A) gene. Patients with this mutation typically face a higher risk of relapse and have a median overall survival rate of less than one year.

Syndax plans to introduce two dosages of Revuforj, priced at approximately $475,000 annually before any rebates or discounts, by November. A lower dose version tailored for lighter patients is expected to be available next year.

The FDA's approval came ahead of its scheduled deadline of December 26. The green light was given based on data from trials involving 104 patients treated with the drug. In these early-stage trials, a little over 20% of the participants achieved complete remission, which lasted an average of about six months. Additionally, 23% of the participants proceeded to undergo stem cell transplants following their treatment with Revuforj.

However, the drug's labeling includes a black box warning for differentiation syndrome, which affected 29% of the 135 patients treated with Revuforj. Differentiation syndrome, also known as retinoic acid syndrome, is a potentially life-threatening reaction to cancer treatments in individuals with acute leukemia. According to Jefferies analyst Kelly Shi, this warning was anticipated and is similar to warnings for nearly all other therapies targeting acute myeloid leukemia (AML).

Initially, Syndax will offer Revuforj in 110 milligram and 160 milligram doses, with a 25 milligram tablet to follow. The company estimates that there are around 2,000 people in the United States with acute leukemia featuring the KMT2A translocation. Shi notes that most patients are expected to have commercial insurance coverage due to their younger age and projects that peak annual sales of Revuforj for the KMT2A indication could eventually reach approximately $200 million.