The US Food and Drug Administration (FDA) recently approved two biosimilars to Soliris for the treatment of two rare diseases — paroxysmal nocturnal hemoglobinuria (PNH), a debilitating and potentially deadly blood disorder, and atypical hemolytic uremic syndrome.
The first, Bkemv (eculizumab-aeeb, Amgen), was approved in May, and the second, Epysqli (eculizumab-aagh, Samsung Bioepis), was approved last week.
Soliris (eculizumab, Alexion) is an intravenous agent indicated for the treatment of PNH and atypical hemolytic uremic syndrome, as well as generalized myasthenia gravis and neuromyelitis optical spectrum disorder.
Both Bkemv and Epysqli are monoclonal antibodies that bind to complement protein C5 and have been approved previously in Europe. Availability for Bkemv in the United States will be delayed until March 1, 2025 under a patent settlement agreement between Alexion and Amgen.
The FDA approval for Bkemv was based on findings from the double-blind, active-controlled, phase 3 DAHLIA study showing similar efficacy, safety, and immunogenicity to Soliris in adults with PNH. The agents reduce the loss of red blood cells and, thus, the need for blood transfusion in patients with PNH.
The DAHLIA study included 42 adults with PNH who had previously received Soliris for at least 6 months. These patients were then randomized to receive Soliris or Bkemv in one of two sequences delivered across two treatment periods. For study period 1 (weeks 1-53), patients were randomized to either 900 mg of intravenous (IV) Bkemv or Soliris every 14 days for 52 weeks, and for study period 2, the patients crossed over to the other treatment for 26 weeks.
Comparable efficacy was observed in both the parallel and crossover comparisons, with geometric mean values for trough total and unbound concentrations of Bkemv and Soliris similar between the treatment groups at all time points tested. Control of intravascular hemolysis was measured by lactate dehydrogenase at week 27 for the parallel comparison and by time-adjusted area under the effect curve of lactate dehydrogenase from weeks 13 to 27, from weeks 39 to 53, and from weeks 65 to 79 for the crossover comparison.
The approval for Epysqli was on the basis of phase 3 trial findings, in which 50 patients with PNH were randomized to Epysqli or Soliris through week 26, after which the treatment was switched and provided until week 50. The findings showed a mean difference in lactate dehydrogenase level at week 26 between Epysqli and Soliris was 34.48 U/L, which fell within the predefined equivalence margin. The ratio of time-adjusted area under the effect curve of lactate dehydrogenase between the two was 1.08 — also within the predefined equivalence margin — indicating bioequivalence between the biosimilar and reference product.
Similar to Soliris, the prescribing information for Bkemv and Epysqli includes a boxed warning associated with an increased risk for serious meningococcal infections. Due to this risk, both biosimilars are only available under a Risk Evaluation and Mitigation Strategy program that prescribers are required to enroll in.
According to drugs.com, Soliris (10 mg/mL) IV solution comes to about $6878 for a supply of 30 milliliters; cost information for the biosimilars is not available yet.
Sharon Worcester, MA, is an award-winning medical journalist based in Birmingham, Alabama, writing for Medscape Medical News, MDedge, and other affiliate sites. She currently covers oncology, but she has also written on a variety of other medical specialties and healthcare topics. She can be reached at sworcester@mdedge.com or on X @SW_MedReporter.