BELCHER PHARMACEUTICALS v. HOSPIRA, INC.
Before Reyna, Taranto, and Stoll. Appeal from the District of Delaware.
Summary: A patentee committed inequitable conduct by advancing an argument during patent prosecution that contradicted the patentee’s prior arguments and evidence submitted to the FDA.
Belcher Pharmaceuticals, through its Chief Science Officer, Mr. Rubin, sought and received approval from the FDA for a drug formulation of l-epinephrine. To obtain this approval, Belcher relied on prior literature that described the well-known effects of a 2.8 to 3.3 pH range on the racemization of l‑epinephrine.
Mr. Rubin later helped prosecute a patent application for Belcher’s drug formulation. To distinguish prior art that described a similar formulation with a pH range of 2.2 to 5.0, Belcher argued that a range of 2.8 to 3.3 was “unexpectedly found to be critical” by the inventor for reducing racemization. Accepting this argument, the USPTO issued a patent to Belcher.
Belcher asserted its patent against Hospira in an infringement suit under the Hatch-Waxman Act. Hospira argued that the patent was unenforceable due to inequitable conduct. The district court agreed, finding that Mr. Rubin had failed to disclose prior art references that were but-for material to patentability because they disclosed the allegedly unexpected pH range. The court also found that Mr. Rubin was aware of these references, and their disclosure of the claimed pH range, due to his work on the FDA approval of Belcher’s drug formulation. Thus, Belcher’s patent was unenforceable. Belcher appealed.
Belcher argued on appeal that Rubin believed the references he withheld from the Patent Office were irrelevant because they failed to disclose certain features other than the claimed pH range. The Federal Circuit found no clear error in the district court’s finding that this excuse was implausible and not credible, in view of the record evidence. The Federal Circuit thus affirmed the district court’s judgment of unenforceability.