Selenious Acid
Case Name: In re Selenious Acid Litigation, Civ. No. 24-7791-BRM-CLW, 2025 WL 1900949 (D.N.J. July 8, 2025) (Martinotti, J.)
Drug Product and Patent(s)-in-Suit: Selenious Acid; U.S. Patent Nos. 11,998,565 (“the ’565 patent”) and 12,150,957 (“the ’957 patent”)
Nature of the Case and Issue(s) Presented: Plaintiff American Regent, Inc. (“ARI”) sued multiple ANDA filers (including Sun, Cipla, RK Pharma, and Aspiro) under § 271(e)(2) of the Hatch Waxman Act, and moved for a preliminary injunction. The ’565 patent claims the compositions of the selenious acid injections, and the ’957 patent claims their methods of use. Because Defendants filed their ANDAs prior to the issuance of the patents-in-suit, the 30-month stay was not triggered, making preliminary relief dispositive for near-term market entry. After considering ARI’s motion, the court granted a preliminary injunction.
Why ARI Prevailed: The court first addressed ARI’s likelihood of success on the merits. ARI argued that Defendants could not raise a substantial question of validity. To make their case, Defendants focused on the fluoride concentration described in claim 1 of both patents, arguing that those claim limitations failed to satisfy the written description requirement. Specifically, Defendants argued that the claim language describing “fluoride in an amount of 0.0001 μg to 2.7 μg per 1 mL” is absent from the specifications of the patents-in-suit and there is no evidence to demonstrate to a POSA that Plaintiff “possessed injectable compositions containing fluoride in a range of 0.0001 to 2.7 μg/mL.” The court disagreed. The specifications of the patents-in-suit (including the original claim set) expressly disclosed fluoride “from about 0.0001 to about 2.7” in the context of an injectable composition measured in μg per 1 mL, which a POSA would read as the same per-mL units recited in the asserted claims. The court noted that the original claims are part of the specification and can satisfy written description. Additionally, the prosecution history reinforced this reading: the examiner specifically focused on fluoride and recommended inclusion of the 0.0001–2.7 μg/mL numerical range to place the claims in condition for allowance, noting the prior art lacked a selenium-with-fluoride composition in the relevant range. The court also emphasized that here the patents discuss dosing information from which the claimed numerical subset is directly drawn—an approach Federal Circuit law permits.
Next, on the current record, the court found it “highly likely” the ANDA products meet every element of the asserted composition claims, including the fluoride-range limitation. Defendants’ own manufacturing inputs and water sourcing made it very unlikely that purification would reduce fluoride below 0.0001–2.7 μg/mL; the data the Court credited (e.g., distributions of likely source-water fluoride) indicated most sources cluster above levels that would end up below the claimed ceiling after processing. Defendants offered no concrete proof that they used outlier, ultra-low-fluoride water. In reference to the method claims, the court recognized that in the Hatch–Waxman context, an ANDA label that instructs the patented method can supply the specific intent required for induced infringement.
The court then examined whether ARI would be irreparably harmed without injunctive relief. The court noted and credited the fact that the parties are direct competitors in a niche parenteral-nutrition market. The court also pointed to effects such as immediate price erosion, loss of customer relationships and goodwill, and broader “ecosystem” effects driven by contract dynamics—harms not readily compensable by money damages.
Concerning the balance of equities and public interest, the court found that the equities did not tip against an injunction. The court emphasized that Federal Rule of Civil Procedure 65(c) security is the enjoined parties’ principal protection if the injunction later proves wrongful, and therefore required a monetary bond. The court found no “critical public interest” would be harmed by preserving the status quo while validity and infringement are adjudicated. Protecting patent rights pending a merits decision modestly advances the public’s interest in pharmaceutical innovation, notwithstanding the general interest in lower-cost generics.
