Fish & Richardson Secures Win for Exela Pharma Sciences in ELCYS® Patent Infringement Litigation

Fish & Richardson secured a significant victory for Exela Pharma Sciences, LLC, the maker of ELCYS^®, in patent infringement litigation against Eton Pharmaceuticals, Inc., over its intent to produce a generic version of Exela's patented ELCYS^® product. ELCYS^® is the only FDA-approved cysteine hydrochloride injection on the market for use as an additive to amino acid solutions to meet the nutritional requirements of newborn infants requiring total parenteral nutrition (TPN), and of adult and pediatric patients with severe liver disease who may have impaired enzymatic processes and require TPN.

In her August 8 ruling, Judge Maryellen Noreika of the U.S. District Court for the District of Delaware agreed with Fish that Eton's Abbreviated New Drug Application (ANDA) product infringes all asserted claims of Exela's patents, and that Exela's patents are not invalid. The court rejected each and every one of Eton's challenges.

"We are pleased that the court wholeheartedly agreed with our arguments and ruled in favor of our client across the board," said Fish principal Corrin Drakulich. "Exela made the first drug of this type with extremely low levels of aluminum, which has been known for decades to be toxic to infants. Protecting Exela's investment in arriving at this innovation will enable it to do further research and development and invest in manufacturing infrastructure to benefit other patients, beyond the fragile infant patients who rely on ELCYS^® every day."

Judge Noreika's ruling is the culmination of a two-and-a-half-year dispute with Eton. Fish filed a Hatch-Waxman lawsuit in the District of Delaware on behalf of Exela in March 2020 against Eton. Eton responded by filing three post-grant review petitions (PGRs) against Exela's ELCYS^® patents in an attempt to invalidate those patents in parallel proceedings. The Patent Trial and Appeal Board agreed with Fish's responsive filings and refused to institute the requested PGRs, ensuring any further validity challenge would be heard in district court. In the district court case, Fish won a key pre-trial motion on behalf of Exela that knocked out Eton's primary non-infringement theory and led to Eton stipulating to infringement of two of the three patents on the eve of trial.

At trial, which lasted three days, a Fish team led by Drakulich successfully proved infringement of the third patent, and rebuffed Eton's claims that the patents were both anticipated and obvious based on prior art products which exhibited the very problems Exela set out to, and did, solve. Marshaling the scientific evidence through opinion leading industry experts, Fish demonstrated that the patent claims are novel and nonobvious.

The case is Exela Pharma Sciences, LLC v. Eton Pharmaceuticals, Inc., C.A. No. 20-365. In addition to Drakulich, the Fish attorneys representing Exela at trial were Betsy Flanagan, Greg Booker, Christina Brown-Marshall, Dexter Whitley, Deanna Reichel, and Karrie Wheatley.

The full court opinion can be viewed here.