FDA Approves First Interchangeable Biosimilar for Rare Diseases

The U.S. Food and Drug Administration (FDA) has announced the approval of Bkemv (eculizumab-aeeb) as the first interchangeable biosimilar to Soliris (eculizumab) for treating specific rare diseases. Bkemv has been authorized for the same indications as Soliris, including the treatment of patients with paroxysmal nocturnal hemoglobinuria (PNH) to reduce hemolysis and the treatment of patients with atypical hemolytic uremic syndrome (aHUS) to inhibit complement-mediated thrombotic microangiopathy.

According to Sarah Yim, director of the Office of Therapeutic Biologics and Biosimilars at the FDA's Center for Drug Evaluation and Research, the FDA is dedicated to fostering the development of safe and effective interchangeable biosimilar treatments. These treatments aim to expand access for individuals with rare diseases who have limited options.

Conditions like PNH and aHUS are rare, affecting fewer than 200,000 people in the U.S. PNH is characterized by the breakdown of red blood cells, leading to anemia, thrombosis, pancytopenia, and dark urine. aHUS also results in anemia and thrombocytopenia and can lead to kidney failure. Bkemv, a monoclonal antibody, binds to the complement C5 protein, inhibiting the complement system’s activation. This mechanism prevents the breakdown of red blood cells in patients with PNH and aHUS.

Both Bkemv and Soliris come with a Boxed Warning regarding an increased risk of serious and life-threatening meningococcal infections caused by Neisseria meningitidis. Patients must complete meningococcal vaccination before starting treatment with either drug. They should also be monitored for early signs of infections and undergo immediate evaluation if symptoms develop.

As an interchangeable biosimilar, Bkemv is highly similar to Soliris, with no clinically meaningful differences. It shares the same safety warnings and is expected to have similar adverse reactions. In clinical trials for Soliris, the most frequently reported adverse reactions in PNH patients included headache, nasopharyngitis, back pain, and nausea. For aHUS patients, common adverse reactions included headache, diarrhea, hypertension, upper respiratory infection, abdominal pain, vomiting, nasopharyngitis, anemia, cough, swelling of lower legs or hands, nausea, urinary tract infections, and fever.

Bkemv is available through a restricted program known as the Bkemv Risk Evaluation and Mitigation Strategy (REMS). REMS is a drug safety program required by the FDA for certain medications with serious safety concerns to ensure the benefits of the medication outweigh its risks.

Bkemv marks the 53rd biosimilar approved in the U.S., with 13 of these being interchangeable biosimilars. An interchangeable biosimilar can be substituted for the reference product without consulting the prescriber, subject to state pharmacy laws. This practice, known as "pharmacy-level substitution," is similar to the substitution of generic drugs for brand-name drugs.

All biological products undergo rigorous approval standards set by the FDA, ensuring that healthcare providers and patients can expect the same safety and effectiveness from both a biosimilar and an interchangeable biosimilar as they would from the reference product.

The FDA's approval of biosimilar and interchangeable biosimilar products supports a competitive marketplace for biological products and increases patient access to more affordable treatment options. The FDA granted the approval of Bkemv to Amgen Inc. This approval signifies a significant advancement in the availability of treatments for rare diseases, providing new hope for patients affected by these conditions.