Buprenorphine & Naloxone – USA

Buprenorphine & Naloxone – USA

On Nov. 24, 2021, Federal Circuit affirmed PTAB’s decision and found claims anticipated by intervening prior art because patent fails to claim valid priority to original application.


Dr. Reddy’s filed IPR (IPR2019-00329) on Nov. 13, 2018 against US 9,687,454 patent, owned by Indivior. On Jun. 02, 2020, PTAB issued final written decision and held claims 1–5, 7, and 9–14 are unpatentable and claim 8 is patentable. The ’454 patent (filed on May 18, 2015) issued as the fifth continuation of US 12/537,571 (the “’571 application”), which was filed on August 7, 2009. Claims 1, 7, 8, and 12 of the ’454 patent are relevant, specifically polymer limitations.


Claim 1. An oral, self-supporting, mucoadhesive film comprising:
(a) about 40 wt % to about 60 wt % of a watersoluble polymeric matrix;
(b) about 2 mg to about 16 mg of buprenorphine or a pharmaceutically acceptable salt thereof;
(c) about 0.5 mg to about 4 mg of naloxone or a pharmaceutically acceptable salt thereof; and
(d) an acidic buffer; wherein…..

Other claims 7 & 12 recite “about 48.2 wt % to about 58.6 wt %” and claim 8 recites “about 48.2 wt %” amount of polymers.


The Board analyzed whether the challenged claims have written description support in the ’571 application. Regarding claim 8’s polymer weight percentage limitation of “about 48.2 wt %,” the Board found that Tables 1 and 5 in the ’571 application disclose formulations from which a polymer weight of 48.2% could be calculated by a person of ordinary skill in the art (POSA). However, the Board found that the ’571 application does not “discuss or refer to bounded or closed ranges of polymer weight percentages” of claims 1, 7 and 12. Therefore, US’454 does not entitle to priority of ‘571 application. Thus, intervening prior art, Myers anticipates the claims. Indivior appealed, and DRL cross-appealed.


During appeal, Indivior argued that the Board erred in finding that the polymer range limitations in claims 1, 7, and 12 lack written description support in the ’571 application. Indivior argued that Tables 1 and 5 disclose formulations with 48.2 wt % and 58.6 wt % polymer. The ’571 application also discloses that “the film composition contains a film forming polymer in an amount of at least 25% by weight of the composition.”


Federal Circuit said that regarding claim 1, we agree with the Board that there is no written description support in the ’571 application for the range of “about 40 wt % to about 60 wt %.” First, the range was not expressly claimed in the ’571 application. It is true that in Table 1 there are four polymer components and when they are added up, each total is within the “about 40 wt % to about 60 wt %” range, but these values do not constitute ranges; they are only specific. Here, one must select several components, add up the individual values, determine the aggregate percentages, and then couple those aggregate percentages with other examples in the ’571 application to create an otherwise unstated range. That is not a written description of the claimed range.


Federal Circuit also agreed with the Board with respect to claims 7 and 12 that there is no written description support for the range of “about 48.2 wt % to about 58.6 wt %” in the ’571 application. Indivior argued that if one looks to Tables 1 and 5, plucks out the polymer components and creates a range from the percentage totals, then one has obtained the range recited in claim 7. But Federal Circuit said that Indivior failed to provide persuasive evidence demonstrating that POSA would have understood from reading the ’571 application that it disclosed an invention with a range of 48.2 wt % to 58.6 wt %. A written description sufficient to satisfy the requirement of the law requires a statement of an invention, not an invitation to go on a hunting expedition to patch together after the fact a synthetic definition of an invention. “[A] patent is not a hunting license.


With respect to claim 8 and its limitation of 48.2 wt %, Federal Circuit agreed with Board and said that DRL failed to prove that the claim is invalid. Federal Circuit gave deference to PTAB’s fact finding and held that the claim 8 is entitled to priority.


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