Eton Pharmaceuticals Confirms First-to-File Patent Challenge on Elcys (Cysteine Hydrochloride Injection)

-Eton confirms first-to-file ANDA referencing Exela Pharma Sciences’ Elcys product

-Eton plans to file Post Grant Reviews in the U.S. Patent & Trademark Office challenging the validity of Exela’s listed patents, which, if successful, could allow Eton to launch in 2021

-Eton believes Exela Pharma Sciences is improperly stifling competition on a decades-old drug

DEER PARK, Ill., May 07, 2020 (GLOBE NEWSWIRE) -- Eton Pharmaceuticals, Inc (Nasdaq: ETON), a specialty pharmaceutical company focused on developing and commercializing innovative drug products, today disclosed that it has been confirmed as the first filer of an Abbreviated New Drug Application (ANDA) against Exela Pharma Science’s Elcys (cysteine hydrochloride injection).

Eton’s Paragraph IV certifications challenge the validity of U.S. Patent Nos. 10,478,453 and 10,583,155, which were issued to Exela Pharma Sciences in 2019 and 2020, respectively.

Eton is the first company to have filed a substantially complete abbreviated new drug application (ANDA) containing a Paragraph IV certification with the U.S. Food and Drug Administration (FDA). If successful, this would entitle Eton to 180 days of generic exclusivity.

Cysteine hydrochloride injection is an old molecule that was sold in the United States for decades as an unapproved product before Exela’s New Drug Application (NDA) approval in 2019. Exela did not conduct any new clinical studies to support its NDA filing, and instead relied on historic published literature to support its safety and efficacy claims. Eton’s own development partner had manufactured and commercialized cysteine hydrochloride injection over fifteen years ago in the same formulation that was claimed to be novel by Exela Pharma Sciences, and as a result, Eton is highly confident that the Exela Pharma Science patents will be invalidated.

In addition, Eton expects to file Post Grant Reviews (PGRs) with the U.S Patent and Trademark Office (USPTO) later this month. The PGR process is an abbreviated pathway to challenge the validity of patents issued by the USPTO. The USPTO is generally required to make a final ruling on a PGR challenge within eighteen months of a challenger’s PGR submission, which would allow for Eton to potentially launch its product as early as November 2021.