Buprenorphine & Naloxone - USA

On Nov 20, 2018, Federal Circuit vacated preliminary injunction granted by district court which was on erroneous interpretation of claim scope.

Indivior markets Suboxone® Film for the treatment for opioid dependency. Suboxone Film is covered by U.S. Patent Nos. 9,931,305 and 8,603,514 which are from same family. The ’305 patent is the only patent at issue in this case. The Delaware Court previously determined that Dr Reddy’s (DRL) ANDA process does not infringe the asserted ’514 patent claims because the drying process was conventional. After the Delaware Court entered its judgment of non-infringement, Indivior amended certain claims of a then pending application that ultimately issued as the ’305 patent. Indivior amended the claims to remove the words “dried” and “drying,” and to add “continuously” and “continuously cast” in their place. DRL launched ANDA on the day of FDA approval when the suit regarding ‘305 was pending.

District court after hearing granted preliminary injunction. In granting the same, the district court concluded that Indivior was likely to succeed on the merits of its infringement claim. It concluded that the claims, which lack an express “drying” limitation, do not exclude any particular drying method. The district court credited Indivior’s expert over DRL’s and declined to import a drying step into the “continuously cast” limitation—the limitation that Indivior added during prosecution to replace the terms “drying” and “dried.” According to the district court, the ’305 claims do not include a drying limitation. Based largely on this reasoning, it determined that Indivior’s suit was not barred by claim preclusion in light of the Delaware Case. The district court considered it likely that Indivior would be able to show that the ’305 claims are “patentably distinct” from the ’514 claims, and thus would likely show that the suit was not barred by claim preclusion. DRL appealed the district court’s grant of the preliminary injunction.

Federal circuit concluded that the district court abused its discretion in granting the preliminary injunction. The ’305 patent specification disclaims solely using conventional top air drying to produce films with the claimed content uniformity. Because the ’305 claims thus do not cover such films, Indivior has not shown that it is likely to succeed on the merits of its infringement claim. Specifically, the patent specification states that “conventional drying methods themselves are unable to provide uniform films.” Conventional drying methods that dry only the top of the film produce a “ripple effect” that results in “an uneven and therefore non-uniform film.” The specification teaches that the rippling effect produced by conventional drying methods can be “avoided by the present invention by “applying heat to the bottom surface of the film with substantially no top air flow”. The ’305 patent also discloses two examples that further disparage the use of conventional drying. The patentee expressly disclaimed the sole use of conventional top air drying to produce the claimed films. Such disavowal places films formed by these methods outside the scope of the ’305 claims.

Indivior argued that removal of the drying terms during prosecution removes any limitation on how the film is dried. According to Indivior, the specification disclaimer found by the Delaware Court in its analysis of the ’514 patent was “rooted in the meaning of the claim language ‘dried’ and ‘drying,’” and does not apply to the ’305 claims because those terms are absent. Court however, disagreed & said that the drying limitation has a textual basis in the term “continuously cast film,” which appears in claims 1 and 26 of the ’305 patent. The “continuously cast film” in claims 1 and 26 requires drying as the film starts out as a liquid and ends up as a solid that can be cut into individual dosages. In the absence of this also for that matter the specification makes clear that the invention does not include films that were dried using conventional top air drying.

Court further held that claim preclusion likely bars Indivior’s suit as the ’514 claims and the ’305 claims are patentably indistinct. The ’305 patent has the same specification as the ’514 patent. The only difference between the ’305 claims asserted here and the ’514 claims asserted in the Delaware Case is that the ’305 claims contain the term “continuously cast” in place of “dried” and “drying.” While the language of the claim terms changed, the scope of the claims did not materially change. The claims of the ’305 patent are thus “patentably indistinct” from those of the ’514 patent. It is further substantiated by Indivior’s filing of a terminal disclaimer over ‘514 patent.

Federal circuit thus vacated & remanded district court’s ruling as it abused its discretion in granting the preliminary injunction.