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CAFC Rules Suboxone Patent is Not Infringed by Generic Buprenorphine Film Product

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CAFC Rules Suboxone Patent is Not Infringed by Generic Buprenorphine Film Product

 

By: Katie Rubino

 

Recently on July 9th the Court of Appeals for the Federal Circuit (CAFC) ruled that generic versions of buprenorphine and naloxone film products do not infringe patents held on the Suboxone brand name product. Dr. Reddy’s Laboratories (DRL) appealed from several decisions of the U.S. District Court (district court) in regards to U.S. Patent 8,603,514 (‘514) and 8,017,150 (‘150) directed at methods of manufacturing film drug products that create orally disintegrating drugs. Indivior Inc., and Aquestive Therapeutics (Indivior) cross appealed several decisions from district court.

Currently, Indivior owns the new drug application (NDA) for Suboxone film, a rapid orally disintegrating delivery mechanism containing buprenorphine and naloxone. The rapid film delivery was approved by the Food and Drug Administration (FDA) in 2010. Prior to this delivery mechanism, Suboxone was only available in tablet form. Suboxone film is a drug product intended for the treatment of opioid addiction, and administered under the tongue or inside the cheek. Upon placement in the mouth, the film dissolves without the need to swallow or take the medication with a beverage such as water. Suboxone film contains two active ingredients, buprenorphine and naloxone. Buprenorphine works as a partial agonist to active mu-opioid receptors to produce similar effects as opioids such as feelings of analgesia and euphoria. Naloxone is an opioid antagonist that blocks the effect of opioids and prevents misuse of the medication.

This appeal to the CAFC is directed at claims of patent infringement and patent invalidity surrounding two central patents, the ‘514 and the ‘150, both of which are directed at pharmaceutical films and methods of making pharmaceutical films.

The ‘514 and ‘150 patents are owned by Aquestive Therapeutics, Inc. and licensed to Indivior. The ‘514 patent claims pharmaceutical films with a uniform distribution of an active ingredient, a requirement put into place by regulatory agencies such as the FDA. While required by the FDA and covered by the ‘514 patent, uniform distribution is difficult to maintain in practice. The ‘514 contains claims directed at specific manufacturing processes, including limitations that include a drying step.

The ‘150 patent is directed at uniform pharmaceutical films as well, but contains claims directed at specific components and ingredients used to manufacture pharmaceutical films. The ‘150 patent contains specific ingredients used in the pharmaceutical films including polyethylene oxide (PEO) alone and in combination with polyvinyl pyrrolidone.

Several manufactures of generic drug products filed abbreviated new drug applications (ANDAS) to manufacture generic versions of Suboxone Film prior to expiration of the ‘514 and ’150 patents. At that time, Indivior brought suit claiming patent infringement of the ‘514 and ‘150 patents, in addition to several other related patents.

This appeal centers around Indivior’s suit against DRL over the ‘514 patent. Upon filing suit in district court, Indivior claimed that DRL infringed the ‘514 patent, and arguments ensued concerning the meaning of the drying limitation contained within the ‘514 patent. The district court found that DRL did not infringe the ‘514 patent because DRL’s drying process was performed differently than the method contained within the ‘514 patent.

After the district court found noninfringement by DRL against the ‘514 patent, Indivior amended claims contained within a continuation application to remove “dried” and “drying” from claims contained within that application. That continuation application then issued as U.S. Patent 9,931,305 (‘305), which Indivior then used to subsequently file suit against DRL claiming patent infringement. District court found that Indivior would likely be able to prove infringement and a temporary restraining order was granted to enjoin the manufacture of DRL’s generic film product. DRL then appealed to the CAFC. CAFC held that Indivior’s action was likely claim precluded, and vacated the preliminary injunction against DRL. DRL then appealed that claims of the ‘514 and ‘150 patents were invalid as obvious. Indivior cross-appealed that DRL did not infringe the ‘514 or the ‘150 patent.

In addition, at district court Indivior filed suit against DRL claiming infringement of the ‘150 patent. At a separate trial, district court held that DRL did not infringe the ‘150 patent.

First on appeal at the CAFC, in regards to the ‘514 patent, the CAFC held that district court abused its discretion in entering a preliminary injunction against DRL. Indivior argued that the district court erred in the interpretation of the drying method described in the ‘514 patent, and that it should be given its plain and ordinary meaning. CAFC held that the district court correctly construed the drying limitation, given the definition as described in the specification.

In regards to DRL’s assertion of obviousness, the CAFC ruled with Indivior in concluding that the district court did not err in its judgement of nonobviousness. The CAFC agreed with the district court that a person of ordinary skill in the art would be someone on a team such as an engineer or scientist with experience and knowledge about films. The CAFC also agreed with the district court that the other cited art including the Schmidt reference and the Chen reference did not teach methods relating to uniform films as described in the ‘514 patent. The CAFC therefore concluded that the claims of the ‘514 patent would not have been obvious to one of ordinary skill in the art.

Lastly, in regards to obviousness surrounding the ‘150 patent, the CAFC also agreed with district court regarding claims of obviousness. The CAFC affirmed a finding of nonobviousness for reasons similar to the ‘514 patent.

While this case on appeal to the CAFC, in April of this year, Indivior was indicted by a federal grand jury that it made unsubstantiated claims that the Suboxone film product was less prone to abuse than tablet forms of Suboxone. The government is currently seeking $3 billion in damages for these unsubstantiated claims, and a trial is set to decide this case next year in 2020.

Subsequently, one day after this decision from the CAFC, Indivior agreed to pay $1.4 billion to settle a case with the Department of Justice (DOJ) and the Federal Trade Commission (FTC) also involving substantiated claims about the film product. Looking ahead, it will be interesting to see how these pending suits impact availability of brand name Suboxone film products. Generic drug makers such as DRL may have more opportunities to be substituted beyond the pharmacy counter.

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