An Agios Pharmaceuticals drug developed to treat a rare form of leukemia has received FDA approval ahead of schedule. This marks the second time in the past year that the company has won the regulatory nod for a treatment for the disease, but this is the first approved drug that’s wholly owned by the Cambridge, MA-based firm.
The Agios (NASDAQ: AGIO) drug ivosidenib (Tibsovo), is a treatment for acute myeloid leukemia (AML), a progressive and deadly cancer of the bone marrow and blood. The Agios drug was approved for patients who haven’t responded to earlier treatments and whose cancer has a specific genetic mutation. That mutation is detected with an FDA approved test. But the drug’s approval comes with a warning that the treatment can also lead to a potentially fatal complication. Agios set a $26,115 wholesale price for a 30-day supply of ivosidenib. Patients in the clinical trial were treated for a median of four months. The company is working to make the drug available within the next two days.
The target date for an FDA decision on ivosidenib was Aug. 21. Despite the early approval decision, Agios’ stock price dipped Friday morning and has been hovering below Thursday’s $91.18 closing price.
Of the more than 60,000 new cases of leukemia projected to be diagnosed this year, about one third will be AML, according to the American Cancer Society. A fraction of those patients— approximately 6 to 10 percent—have cancers that have a mutation on the IDH1 enzyme and can be targeted by the newly approved drug, Agios says.
Agios develops “cancer metabolism” drugs. The company’s therapies aim to block the ways that cancers feed themselves and grow. The IDH1 enzyme normally helps cells generate energy. But in AML, the mutated enzyme leads to platelets and blood cells that don’t develop properly and multiply wildly. The Agios drug, a pill, was developed to bind to the mutated enzyme, which in turn allows blood cells to develop properly.
The accelerated approval of ivosidenib is based on an open-label, Phase 1 study that tested the drug in 174 patients with confirmed IDH1 mutations. The main goals of the study were complete remission and specific signs of improvement of the disease in the bone marrow and blood (known as “hematological improvement”), such as a recovery in the number of circulating platelets and red and white blood cells.
In the study, 24.7 percent of patients showed a complete remission, Agios reported. The rate of patients who showed hematologic improvement along with complete remission was 32.8 percent. Agios reported that 110 patients who were dependent on transfusions of red blood cells or platelets at the start of the trial no longer needed them 56 days after the start of treatment.
The most common side effects from ivosidenib included fatigue, a high white blood cell count, and joint pain. Ivosidenib’s approval comes with a boxed warning on its label stating that some patients treated with the drug experienced symptoms of differentiation syndrome, a complication in leukemia patients that can be fatal if untreated. Symptoms include fever; difficulty breathing; inflammation in the lungs; fluid around the heart and lungs; and dysfunction in the liver, kidneys, or other organs. The FDA says that at the first sign of symptoms, patients should be treated with steroids and monitored. In the clinical trial, 19 percent of patients treated with the Agios drug experienced differentiation syndrome, the company said.
The FDA’s decision on ivosidenib follows last year’s approval of enasidenib (Idhifa) for the same type of leukemia. That drug originated in Agios’ labs and went on to be developed in partnership with Summit, NJ-based Celgene (NASDAQ: CELG). Enasidenib is also a cancer metabolism drug, but targets a different enzyme, IDH2. According to Celgene estimates, between 8 and 19 percent of AML patients carry an IDH2 mutation. Celgene brought the drug to the market with a list price of $24,872 per month. Agios is receiving a share of Celgene’s U.S. profits from the drug. Celgene holds rights to the drug in the rest of the world. The rights to ivosidenib belong entirely to Agios. The company says that based on the FDA-approved label, an estimated 700 to 1,100 patients in the U.S. will be eligible for treatment with ivosidenib annually.
Image of human cells with acute myeloid leukemia by the National Cancer Institute