The Food and Drug Administration on Friday approved Sanofi's Enjaymo to treat a rare form of anemia 15 months after the regulator rejected the medicine due to manufacturing issues. The French drugmaker said it will begin selling the drug in the U.S. "in coming weeks."

Sanofi set a list price of $1,800 per 1,100 milligram vial, which comes to about $280,000 per year for people weighing less than 75 kilograms. Up to 5,000 people in the U.S. may have the rare illness, which occurs when the immune system attacks and destroys red blood cells.

Enjaymo is the first new drug to emerge from Sanofi's $11 billion acquisition of Bioverativ, a blood disease company spun out of Biogen in 2017. A second experimental drug from that transaction, a long-lasting hemophilia treatment called efanesoctocog alfa, is currently in advanced clinical testing. Sanofi has spent years trying to build a portfolio of rare disease drugs through acquisitions, buying up companies like Genzyme and, more recently, Kadmon and Ablynx. The Bioverativ deal was among those pursuits, giving Sanofi two marketed hemophilia drugs known as Eloctate and Alprolix and other rare disease treatments in various stages of testing.

 

But Bioverativ was facing competitive hurdles when Sanofi acquired it in 2018. Though the French drugmaker touted the growing market for Eloctate and Alprolix, two so-called factor replacement therapies, new hemophilia treatments were moving fast through clinical testing. One drug from Roche, Hemlibra, has become a multi-billion dollar seller. Experimental gene therapies are inching closer to market as well. In 2021 the combined sales of those two drugs shrank to 977 million euros, or about $1.1 billion.

 

Bioverativ is paying dividends for Sanofi in other ways, though. The biotech had a pipeline of blood disease treatments, of which Enjaymo, or sutimlimab, was a part. The condition it treats is called cold agglutinin disease, a rare disease in which antibodies mistakenly tag red blood cells for destruction. The disorder causes shortness of breath, fatigue and anemia because patients can't make enough new red blood cells to replace the old ones.

 

Enjaymo is one of two drugs Bioverativ has been developing for the disorder. The second one, now called SAR445088, is a more convenient version of Enjaymo injected subcutaneously, rather than through intravenous infusions.

 

Bioverativ's experimental hemophilia drugs were a big part of the acquisition, too, especially as treatment for the genetic disorder continues to evolve. Doctors have been seeking to reduce or eliminate infusions of synthetic bleed-preventing clotting factors, either by developing longer-acting synthetic versions or by manipulating the genes to help patients restart production of their own clotting factor.

 

Efanesoctocog alfa is the lead hemophilia treatment from Bioverativ and is now in late-stage development as a once-weekly treatment for hemophilia A, compared with a three-to-five day interval for Eloctate. The deal also gave Sanofi an experimental hemophilia B treatment called BIVV002 that could be delivered through more convenient subcutaneous injections.