The Supreme Court unanimously ruled in favor of Sanofi in a patent case against Amgen Thursday morning.

At issue in the technical case were the intellectual property rights for a PCSK9-inhibiting cholesterol drug. Amgen produced one branded under the name Repatha, while Sanofi’s was labeled Praluent. 

Each drug had a distinct antibody with its own unique amino acid sequencing and both companies received patents for the antibodies used in their respective drugs in 2011. Subsequently, Amgen claimed that the French drugmaker violated its additional patents received in 2014 for its antibodies in the drug.

In a decision handed down by Associate Justice Neil Gorsuch, the Court held that Amgen “failed to enable any person skilled in the art . . . to make and use the invention as defined by the relevant claims.”

Additionally, Gorsuch wrote that Sanofi characterized Amgen’s methods to generate additional antibodies as “little more than a trial-and-error process of discovery.”

The case, which ultimately upholds a lower court’s ruling, was argued in late March. The legal battle first appeared on the high court’s radar in late 2021, when Amgen filed a petition for certiorari. 

After the Court granted the California-based pharma giant’s petition, several notable pharma companies filed amicus briefs during the ensuing months in support of Amgen, including GSK, AbbVie and Instil Bio. 

However, numerous other industry players filed amicus briefs in support of Sanofi, including Pfizer, Genentech, AstraZeneca, Bayer AG, Gilead Sciences, Johnson & Johnson as well as Eli Lilly, Ipsen Bioscience and Innovent Biologics.  

About an hour after the decision was handed down, Regeneron, which jointly developed Praluent with Sanofi, issued a statement welcoming the unanimous opinion.

“Bringing innovative new therapies to patients is the core mission of Regeneron, and we were proud to deliver Praluent as the first FDA approved PCSK9 inhibitor,” Regeneron CEO Leonard Schleifer, MD, PhD, said in a statement. “This Supreme Court decision protects access to this medicine and defends our industry and others against overreaching patent claims that cover an entire therapeutic category and could have a chilling effect on bringing life-saving medicines to people in need.”

The Court’s ruling contributed to a slight bump for Sanofi’s stock, while Amgen’s shares slid during the early morning session.

The judiciary defeat is yet another major decision affecting Amgen that has come out of Washington, D.C. this week.

The Federal Trade Commission sued Amgen on Tuesday to halt its $27.8 billion takeover of Irish biotech Horizon Therapeutics.

The agency cited “rampant consolidation” as a major factor in its decision to act, charging that the two companies have too much overlap between their medicines and would potentially “bundle” contracts for payers and pharmacy benefit managers. In separate statements, Amgen and Horizon have refuted these claims. 

Prior to the Court’s ruling being publicly released this morning, a federal court also issued a temporary restraining order on the Amgen-Horizon deal.

Editor’s note: This story has been updated to include commentary from Regeneron.