Pharma, BioPharma

Sanofi drug Enjaymo wins FDA approval to treat anemia from rare blood disorder

A rare disease drug that Sanofi added via its $11.6 billion Bioverativ acquisition is now approved for treating the blood disorder cold agglutinin disease. The regulatory nod makes the antibody drug the first approved treatment for this rare disease that leads to anemia.

 

Anemia caused by the autoimmune disorder cold agglutin disease now has its first approved treatment, a Sanofi drug designed to block a pathway key to the progression of this condition. The FDA’s regulatory nod for the drug, sutimlimab, keeps the French pharmaceutical giant ahead of a rival company aiming to treat the rare disorder in a similar way.

Sanofi’s new medicine, an infusion given every two weeks, will be marketed under the name “Enjaymo.”

In cold agglutin disease, a patient’s immune system mounts an unrelenting attack on red blood cells, causing them to rupture. The “cold” part of the disease’s name is a reference to destruction of these cells that occurs at cold temperatures, the FDA said in its late Friday approval announcement. At these temperatures, antibodies that normally attack bacteria instead attach to red blood cells and cause them to bind together, or agglutinate. These antibodies also mark the red blood cells for destruction by the immune system.

Disease symptoms typically worsen in winter months when the body is exposed to the cold. The FDA estimates cold agglutin disease affects one out of every one million people annually, typically older adults between the ages of 40 and 80. Plummeting red blood cell counts caused by the disorder lead to anemia, which can be managed with blood transfusions.

Cold agglutinin disease is a disorder of the complement system, a part of the innate immune system. Sanofi’s drug is a monoclonal antibody designed to selectively target and block a protein in the complement system called C1. Doing so is intended to block the deposition of antibodies on red blood cells, which in turn stops the cascade of activity that leads to cold agglutinin disease. The Sanofi drug is designed to block C1 without also affecting other complement system pathways.

FDA approval of Enjaymo is based on the results of an open-label Phase 3 study enrolling 24 cold agglutin disease patients who had been treated with blood transfusions in the six months prior to entering the study. Those participants received the experimental Sanofi therapy for up to six months. According to the results, 54% of patients showed a response, which was defined as an increase in hemoglobin, no red blood cell transfusions after the first five weeks of treatment, and no need for other therapies to treat the disorder. The most common side effects reported in the study included respiratory tract infection, viral infections, diarrhea, indigestion, and swelling in the lower legs and hands. Sanofi presented data from the pivotal study during the 2019 annual meeting of the American Society of Hematology.

Following two weekly starter doses, Enjaymo is given every two weeks in doses that are based according to a patient’s body weight: 6,500 mg for those between 39 kg and 75 kg (about 86 pounds to 165 pounds) and 7,500 mg for patients weighing more than 75 kg. Sanofi set a wholesale price, before any rebates or discounts, of $1,800 per vial. Patients weighing between 39 kg to 75 kg require will require six vials for an infusion, which means a single dose costs $10,800. Given that cold agglutinin disease is a chronic condition, the annual cost of the therapy comes to $280,800. It’s more for those who weigh greater than 75 kg because these patients will require an additional vial for each dose.

Enjaymo was initially developed by True North Therapeutics, a biotech that was acquired by Bioverativ in 2017. The following year, Sanofi bought Bioverativ in an $11.6 billion deal. The drug’s approval comes later than Sanofi had hoped. In late 2020, the FDA rejected the pharma giant’s biologics license application citing problems at the site of a third-party manufacturer of the drug. Sanofi said that regulatory review of Enjaymo is still ongoing in Europe and Japan.

Apellis Pharmaceuticals is also tackling complement system diseases, but by addressing a different complement system protein called C3. The Waltham, Massachusetts-based company’s drug pegcetacoplan won FDA approval last year for treating paroxysmal nocturnal hemoglobinuria, another rare blood disorder in which the body attacks red blood cells. The company has said pegcetacoplan has the potential to address other diseases. In 2020, the company struck up an alliance with Sobi, which paid $250 million up front to share in the development of the drug for other indications. The partners expect to begin a Phase 3 study in cold agglutinin disease in the first quarter of this year.

Image: virusowy, Getty Images 

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