A UK High Court has ruled that biosimilar versions of Soliris (eculizumab) developed by Amgen and Samsung Bioepis do not infringe on a patent protecting Alexion Pharmaceuticals' branded treatment for paroxysmal nocturnal hemoglobinuria (PNH). The favorable ruling comes just days after a Canadian court reached the opposite conclusion, barring Amgen's Soliris biosimilar in that market until patent expiry in 2027.
The contrasting decisions highlight the complex and varied legal landscape biosimilar manufacturers must navigate as they seek to bring lower-cost alternatives to market across different jurisdictions.
Patent Claim Construction Central to UK Decision
The UK case hinged on specific interpretations of patent claims covering Alexion's eculizumab, a complement inhibitor approved for treating PNH, a rare and life-threatening blood disorder. The court's ruling centered on claim construction—the legal interpretation of what a patent actually covers—finding that the biosimilar products developed by California-based Amgen and South Korea's Samsung Bioepis fall outside the scope of Alexion's protected intellectual property in the UK.
Legal experts note that such differences in patent interpretation across jurisdictions are not uncommon in pharmaceutical litigation, particularly for complex biologic medicines where manufacturing processes and molecular structures can be interpreted differently by courts.
Divergent Global Landscape for Biosimilar Access
The UK decision stands in stark contrast to the recent Canadian ruling that prevents Amgen from marketing its Soliris biosimilar in Canada until 2027. This divergence underscores the fragmented global market access picture for biosimilars, where patients in some countries may gain access to lower-cost alternatives years before others.
"These contrasting decisions reflect the complexity of biosimilar litigation globally," said a pharmaceutical patent attorney familiar with the case who requested anonymity. "What constitutes infringement in one jurisdiction may not in another, creating a patchwork of market access opportunities for biosimilar developers."
Implications for PNH Patients and Healthcare Systems
Paroxysmal nocturnal hemoglobinuria affects approximately 1-1.5 people per million worldwide. The condition causes red blood cells to break down prematurely, leading to symptoms including fatigue, difficulty swallowing, abdominal pain, and potentially life-threatening blood clots.
Soliris has been a breakthrough treatment for PNH patients but comes with a significant price tag—estimated at over $500,000 per patient annually in some markets. Biosimilar competition could substantially reduce treatment costs and improve access for patients.
The UK decision potentially opens the door for Amgen and Samsung Bioepis to launch their biosimilar versions in this market, subject to regulatory approval and any further legal challenges. Healthcare systems like the UK's National Health Service stand to benefit from the cost savings associated with biosimilar competition.
Broader Context of Biosimilar Litigation
The Soliris case is part of a broader trend of intense litigation surrounding high-value biologic medicines. Similar legal battles are playing out globally for other major biologics including Johnson & Johnson's Stelara (ustekinumab), where court documents recently revealed ongoing litigation over a private-label biosimilar being marketed in the US by Sandoz and Samsung Bioepis.
Industry analysts note that originator companies are increasingly deploying sophisticated patent strategies to protect their biologics franchises, while biosimilar developers are becoming more adept at navigating these legal challenges.
What's Next for the Parties
While the UK ruling represents a significant victory for Amgen and Samsung Bioepis, the companies will likely face continued legal challenges in other markets. Alexion, now part of AstraZeneca, may appeal the UK decision or pursue alternative legal strategies to protect its valuable franchise.
For patients with PNH, the varied legal outcomes mean that access to potentially lower-cost biosimilar alternatives will depend largely on where they live, with UK patients potentially gaining access sooner than their Canadian counterparts.
Market observers will be watching closely to see how quickly Amgen and Samsung Bioepis move to capitalize on the favorable UK ruling, and whether this decision influences pending litigation in other jurisdictions.
