On Oct. 20, 2022, Delaware Court denied Plaintiff’s motion to strike down “unclean hand” counterclaim and defense raised by Defendant.

 

Plaintiff (Allergan) sued defendant (Sun pharma) for infringement of patents related to product, Viberzi (Eluxadoline), as Sun filed ANDA to market generic version. Allergan initially sued Sun for infringement of US 9,675,587 and US 10,188,632 patents and then added later patents when they got issued subsequently. These patents are: US 11,007,179; US 11,090,291; US 11,160,79; US 11,229,627 and US 11,311,516. Sun in its latest amended answers (May 27, 2022) raised counterclaim and affirmative defense that the ‘516 Patent is unenforceable because of Allergan’s unclean hands.

 

Sun alleged that prior to the date suit was filed in 2019, Allergan consistently prosecuted patent applications that recited “colloidal silicon dioxide” as a required limitation in “each and every claim.” After Allergan “had accessed Sun’s confidential information regarding its ANDA Product formulation,” Allergan eliminated the limitation requiring “colloidal silicon dioxide” from claims in the patent application. Allergan thus later used Sun’s confidential information to draft claims in the ‘516 Patent to “not explicitly require colloidal silica in an improper attempt to cover Sun’s ANDA Product Formulation, which [Allergan] did not invent.” Allergan moved to dismiss or stricken the Sun’s claims.

 

Court said that the pleadings standard for unclean hands depends on the specific conduct alleged. It further said that Rule 8 is the correct standard to apply in the present case. Sun has only claimed that Allergan has committed litigation misconduct, not fraud. Courts have applied Rule 8 to analyze similar unclean hands pleadings. (Jazz Pharms., Inc. v. Roxane Lab ys, Inc., 2013 WL 6858765, D.N.J. Dec. 30, 2013). Court further said that Sun has sufficiently stated a claim for unclean hands. Sun has alleged facts to show that Allergan changed its strategy for prosecuting patents – by eliminating the inclusion of “colloidal silicon dioxide” as a limitation to certain claims – after it had access to Sun’s confidential information pertaining to Sun’s ANDA formulation.

Allergan cited to Kingsdowne Med. Consultants, Ltd v. Hollister Inc., 863 F.2d 867, 874 (Fed. Cir. 1988), for the proposition “that there is nothing improper, illegal or inequitable in filing a patent application for the purpose of obtaining a right to exclude a known competitor’s product from the market; nor is it in any manner improper to amend or insert claims intended to cover a competitor’s product the applicant’s attorney has learned about during the prosecution of a patent application.” Sun claimed that Allergan drafted its claims to cover an invention that Allergan had not invented, using Sun’s confidential information, so that it would cover Sun’s ANDA formulation. The conduct goes beyond simply drafting claims to cover a known competitor’s product. (Natera, Inc. v. Genosity, Inc., 2022 WL 767602, D. Del. March 14, 2022).

 

Court finally held that Sun has alleged facts to state a plausible claim that Allergan acted with unclean hands, and that the ‘516 Patent is therefore unenforceable. Court also denied Allergan’s motion to strike other defenses such as Prosecution History Estoppel and Patent misuse raised by Sun.