Pfizer Inc. has secured a decisive victory in its patent challenge against uniQure Biopharma BV's gene therapy patents, with the US Court of Appeals for the Federal Circuit upholding the invalidation of key intellectual property protecting Hemgenix, a treatment for hemophilia B.
On May 22, 2025, the Federal Circuit affirmed the Patent Trial and Appeal Board's final written decisions in three inter partes review proceedings, finding all challenged claims of uniQure's U.S. Patent Nos. 9,982,248 and 10,465,180 unpatentable. The patents cover viral vectors that encode mutated versions of the coagulation Factor IX gene and methods for treating patients with blood clotting disorders using these vectors.
Patent Invalidation on Obviousness and Anticipation Grounds
The Federal Circuit found that the Patent Trial and Appeal Board correctly determined that the '248 patent was obvious and the '180 patent was anticipated by prior art. The court noted the Board's thorough analysis that spanned over 150 pages, finding no legal error and substantial evidence supporting the tribunal's conclusions.
For the obviousness determination, while it was undisputed that prior art taught each limitation of the independent claims and that a person of ordinary skill would have motivation to combine the references, uniQure argued that success would not have been reasonably expected. However, the Board found Pfizer's experts and the language of the '248 patent persuasive in demonstrating that a person of ordinary skill would have reasonable expectation of success using the "conservative" substitutions claimed in the patent, despite gene therapy being considered an unpredictable art.
The Federal Circuit rejected uniQure's arguments that the Board's opinions were tainted by impermissible hindsight and violated the Administrative Procedure Act. The court also agreed with the Board that substantial evidence from Pfizer's expert supported the obviousness of the dependent claims.
Failure to Establish Nexus for Nonobviousness Evidence
Regarding uniQure's objective evidence of nonobviousness, including long-felt need, praise, copying, and unexpected results, both the Board and Federal Circuit found that uniQure failed to demonstrate the required nexus between its objective evidence and the challenged claims. Even if some nexus existed, the court determined it was weak given that the evidence was not commensurate with the scope of the claims.
Anticipation Finding Upheld
For the anticipation challenge against the '180 patent, the Federal Circuit supported the Board's finding that prior art disclosed all elements of the claimed invention. The court determined that a person of ordinary skill, reading the prior art reference, could "at once envisage the claimed embodiment" given that the prior art disclosed a limited class of two or three preferred amino acid substitutions.
The Federal Circuit also agreed with the Board that the prior art embodiment was presumed enabled despite not being claimed, and that uniQure had not successfully rebutted this presumption.
Impact on Hemgenix Gene Therapy
The invalidated patents relate to uniQure's Hemgenix (etranacogene dezaparvovec-drlb), a gene therapy indicated for treatment of certain patients with hemophilia B, also known as Christmas disease. The therapy involves nucleic acids that encode for a variant of human factor IX protein to address this rare genetic bleeding disorder.
This Federal Circuit decision represents a significant blow to uniQure's intellectual property protection for its hemophilia B gene therapy, potentially opening the door for generic competition and affecting the company's market exclusivity for this treatment approach.
