FDA approves first interchangeable biosimilar for Soliris

On May 28, 2024, the United States FDA approved the first interchangeable biosimilar for Solaris (eculizumab) to treat certain rare diseases. Bkemv (eculizumab-aeeb) is now approved to manage hemolysis in patients with paroxysmal nocturnal hemoglobinuria (PNH) and inhibit complement-mediated thrombotic microangiopathy in atypical hemolytic uremic syndrome (aHUS) patients.

PNH is a rare autoimmune blood disorder in which the immune system attacks and damages red blood cells and platelets. According to the Cleveland Clinic, the condition commonly leads to hemolytic anemia, chronic kidney disease (CKD), and thrombosis.

Atypical hemolytic uremic syndrome is another rare blood disorder. This condition is linked to genetic mutations that impact immune system function, resulting in blood clots and organ damage.

According to the FDA, Bkemv is a monoclonal antibody that inhibits activation of the complement system by binding to the complement C5 protein. This inhibition prevents the intravascular hemolysis in patients with these rare conditions.

This approval and interchangeable designation mean that providers can prescribe Bkemv, manufactured by Amgen, or Solaris, manufactured by Alexion Pharmaceuticals — which AstraZeneca owns — for either of these conditions. Both drugs come with similar warnings of an increased risk of meningococcal infections and comparable side effect profiles.

In the US, Solaris costs approximately $6,878 for a one-month supply. While many patients may pay a lower cost with insurance or discount cards, the medication’s retail price is expensive. The availability of an interchangeable biosimilar may increase market competition and potentially lower the cost of treatment. Although the price of Bkemv has not been released, historical biosimilar approval indicates it will be available at a lower cost than Solaris.

“Many rare conditions are life-threatening, and many do not have treatments,” said Sarah Yim, director of the Office of Therapeutic Biologics and Biosimilars in the FDA’s Center for Drug Evaluation and Research, in the FDA press release. “The FDA is committed to help facilitate the development of safe and effective interchangeable biosimilar treatments that can expand access for individuals with rare diseases whose current treatment options are limited.”