FDA approves Sanofi's monoclonal antibody treatment for CAD

By Jane Byrne

- Last updated on GMT

© GettyImages/Olivier Le Moal
© GettyImages/Olivier Le Moal

Related tags Monoclonal antibody Sanofi blood disorder

The US Food and Drug Administration (FDA) has approved Enjaymo (sutimlimab-jome) to decrease the need for red blood cell transfusion due to hemolysis in adults with cold agglutinin disease (CAD).

Enjaymo is the first and only approved treatment for people with CAD and works by inhibiting the destruction of red blood cells (hemolysis).

CAD is rare blood disorder that impacts the lives of an estimated 5,000 people in the US.

Bill Sibold, executive VP, head of specialty care, Sanofi, commented on the regulatory milestone: “Until now, people living with cold agglutinin disease haven’t had an approved treatment option to manage the constant destruction of red blood cells. Without healthy, viable red blood cells, a chain reaction of debilitating signs and symptoms can be triggered, starting with severe anemia.”

Third-party manufacturing issues

It hasn’t all been smooth sailing for the French pharma giant to get to this point with the therapy. Sanofi was hit with a rejection letter​ by the FDA back in November 2020 for the drug, which Sanofi acquired as part of the $11.6bn Bioverativ deal​.

The regulatory agency’s Complete Response Letter (CRL) for sutimlimab referenced deficiencies from a pre-license inspection of a third-party manufacturing facility. The FDA did not question the clinical data or safety.

Satisfactory resolution of the observations by the third-party manufacturer was required before the BLA could be approved.

C1 inhibition

A humanized monoclonal antibody, Enjaymo is designed to selectively target and inhibit C1s in the classical complement pathway, which is part of the innate immune system. By blocking C1s, Enjaymo inhibits the activation of the complement cascade in the immune system and inhibits C1-activated hemolysis in CAD to prevent the abnormal destruction of healthy red blood cells. Enjaymo does not inhibit the lectin and alternative pathways, said Sanofi.

The drug is administered intravenously weekly for the first two weeks with administration every two weeks thereafter.

The approval of Enjaymo in the US is based on positive results from the 26-week open label, single arm pivotal Phase 3 study in patients with CAD with a recent history of blood transfusion, also known as the CARDINAL study.

The company said the drug met the primary and secondary endpoints in the trial and demonstrated sustained inhibition of classical complement pathway mediated hemolysis with improvements in anemia within one week of treatment.


The drug is expected to be available in the US in the coming weeks, with the list price of Enjaymo coming in at $1,800 per vial.

Sanofi said actual costs to patients are generally anticipated to be lower as the list price does not reflect insurance coverage, co-pay support, or financial assistance from patient support programs. 

Outside of the US, sutimlimab has been submitted to regulatory authorities in Europe and Japan. Those reviews are ongoing, said the company.

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