The U.S. Food and Drug Administration (FDA) has approved Epysqli (eculizumab-aagh), a biosimilar to Soliris (eculizumab), for the treatment of paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS). This approval marks a significant step towards providing more accessible and cost-effective treatment options for patients with these rare and debilitating conditions. The announcement was made by Samsung Bioepis Co., Ltd. on July 22, 2024.
Clinical Equivalence Demonstrated
The FDA's decision was supported by a comprehensive data package, including analytical, non-clinical, and clinical studies. These studies demonstrated that Epysqli is highly similar to Soliris, with no clinically meaningful differences in terms of safety, purity, and potency. Key studies included a randomized Phase 1 trial (NCT03722329) in healthy volunteers, which established pharmacokinetic equivalence and comparable pharmacodynamic, safety, tolerability, and immunogenicity profiles. Additionally, a randomized Phase 3, double-blind, multicenter, cross-over study (NCT04058158) in PNH patients confirmed clinical equivalence in efficacy, safety, pharmacokinetics, and immunogenicity between Epysqli and Soliris.
Impact on Rare Disease Treatment
Christopher Hansung Ko, President and CEO of Samsung Bioepis, emphasized the importance of this approval for the PNH and aHUS communities. "The FDA approval of Epysqli as a biosimilar to Soliris marks an important milestone for PNH and aHUS communities since biosimilars have a potential to positively impact patients and healthcare systems by reducing healthcare costs and improving access to treatments," he stated. He further added that Samsung Bioepis is committed to improving patient lives by providing quality-assured, safe, and effective biologic medicines, expanding their work into rare disease areas.
Addressing Unmet Needs in PNH and aHUS
Eculizumab, a monoclonal antibody and anti-C5 complement inhibitor, is a well-established treatment for PNH and aHUS. These are rare diseases, with an estimated US prevalence of approximately 50,000 and 5,000, respectively. However, the high cost of treatment with Soliris has been a barrier for many patients. Studies indicate that approximately 70% of eculizumab-treated PNH patients are not dosed according to the label, and two-thirds discontinue treatment within an average of 1.5 years, potentially due to financial constraints. The introduction of Epysqli as a biosimilar aims to alleviate this financial burden and improve access to necessary biologic therapies.
Safety Information and REMS Program
Epysqli carries a boxed warning regarding the risk of serious meningococcal infections. The drug is available only through a restricted program under a Risk Evaluation and Mitigation Strategy (REMS) called Epysqli REMS. Patients must be vaccinated against Neisseria meningitidis at least two weeks prior to the first dose of Epysqli, and healthcare providers must monitor patients for early signs and symptoms of meningococcal infections. The most frequently reported adverse reactions in clinical trials with the reference eculizumab include headache, nasopharyngitis, back pain, and nausea.
Global Approvals and Availability
In addition to the FDA approval, Epysqli has also been approved by the European Commission (EC) and Korea’s Ministry of Food and Drug Safety (MFDS) as a biosimilar to Soliris for the treatment of patients with PNH and aHUS. The availability of Epysqli in these regions, and now in the US, represents a significant advancement in the treatment landscape for these rare diseases.
