Court Orders Orange Book Patent Delisting in NUEDEXTA Infringement Litigation; But What’s It Good For?

By Kurt R. Karst –      

It was just a few months ago that we posted on what might have been the first decision in a case involving a counterclaim seeking an order to correct or delete patent information from the Orange Book (and that does not concern a patent use code).  In that case, involving OFIRMEV (acetaminophen) Injection (NDA No. 022450), the U.S. District Court for the Southern District of California denied a Motion for Summary Judgment to remove a patent from the Orange Book.  That decision now appears to have been vacated as part of dismissal of the patent infringement litigation.  Ah, but no worries; there’s yet another patent delisting counterclaim decision to take its place.  But the new decision – this time out of the U.S. District Court for the District of Delaware and involving Avanir Pharmaceuticals’ (“Avanir”) NUEDEXTA (dextromethorphan hydrobromide and quinidine sulfate) Capsules (NDA No. 021879; approved on October 29, 2010) – is not a denial of an ANDA sponsor’s attempt to seek Orange Book patent delisting.  Instead, it is an Order to delist a patent.  The net effect of the Order, however, is probably zero, and has left us wondering why one of the ANDA sponsors in the case, Par Pharmaceutical, Inc. (“Par”), in particular, pursued the patent delisting with such vigor. 

By way of background, the 2003 Medicare Modernization Act (“MMA”) added provisions to the FDC Act to give ANDA (and 505(b)(2)) applicants the ability to challenge the listing of a patent in the Orange Book for a brand-name reference listed drug.  Prior to the enactment of the MMA, courts had ruled that there was no private right of action to seek Orange Book delisting of an allegedly improperly listed patent. 

The patent delisting counterclaim provisions at FDC Act § 505(j)(5)(C)(ii)(I) applicable to ANDAs state:

If an owner of the patent or the holder of the approved application under [FDC Act § 505(b)] for the drug that is claimed by the patent or a use of which is claimed by the patent brings a patent infringement action against the applicant, the applicant may assert a counterclaim seeking an order requiring the holder to correct or delete the patent information submitted by the holder under FDC Act § 505(b) or (c)] on the ground that the patent does not claim either – (aa) the drug for which the application was approved; or (bb) an approved method of using the drug.

The MMA also added the same counterclaim provisions at FDC Act § 505(c)(3)(D)(ii)(I) applicable to 505(b)(2) applications.

Outside of the statute’s patent delisting counterclaim provisions, an NDA sponsor may, on its own initiative, request that FDA remove patent information from the Orange Book.  In response, FDA may or may not remove the patent information.  In some instances, FDA continues to list the patent information, but includes a “Patent Delist Request Flag,” which is described by FDA in an Orange Book data file as follows:

Sponsor has requested patent be delisted.  This patent has remained listed because, under Section 505(j)(5)(D)(i) of the Act, a first applicant may retain eligibility for 180-day exclusivity based on a paragraph IV certification to this patent for a certain period.  Applicants under Section 505(b)(2) are not required to certify to patents where this flag is set to Y.  Format is Y or null.

NUEDEXTA is listed in the Orange Book with three patents: (1) U. S. Patent No. 7,659,282 (“the ‘282 patent”) (expiring on August 13, 2026); (2) U.S. Patent No. 8,227,484 (“the ‘484 patent”) (expiring on July 17, 2023); and (3) U.S. Patent No. RE 38,115 (“the ‘115 patent”) (expiring on January 26, 2016).  Only the ‘282 and ‘115 patents were listed in the Orange Book when the first ANDA was submitted to FDA on March 7, 2011 containing a Paragraph IV certification.  Par and Impax Laboratories, Inc. (“Impax”) both certified Paragraph IV to the ‘282 and ‘115 patents (and later to the ‘484 patent as well) and were sued for infringement (here and here).  Par is believed to be the first applicant eligible for 180-day exclusivity. 

Earlier this year, the Delaware District Court ruled in Avanir’s favor, upholding the validity of all three patents, and holding that the proposed ANDA drug products infringe the claims of the ‘282 and ‘484 patents.  At the same time, the court, in response to an earlier counterclaim filed by Par and Impax to “enter an order requiring Plaintiffs to delete the ‘115 patent information that they submitted to the FDA,” said that it had insufficient information to decide on the delisting counterclaim and ordered supplemental briefing on the issue.  Within weeks of that decision, Avanir voluntarily asked FDA to delete the ‘115 patent information from the Orange Book . . . which FDA did by adding a “Patent Delist Request Flag” in relation to the patent information.  Avanir then filed a brief with the court saying that the Par/Impax delisting counterclaims are moot and should be dismissed for lack of subject matter jurisdiction. 

So that was the end of the matter . . . right?  Wrong!

Par and Impax pressed their delisting counterclaims with the court, saying in a brief that the unilateral delisting of the ‘115 patent information was an empty gesture and that an Order from the court is necessary to prevent relisting:

Without a court order, Defendants believe Avanir will not be able to delist the '115 patent.  The FDA will likely decline Avanir’s unilateral request because there is no statutory provision regarding delisting Orange Book patents without a counterclaim. . . .  Without the order provided in the statute and requested by Defendants, Plaintiffs have no barrier against relisting the '115 patent if they can successfully delist it.  Defendants cannot accept Plaintiffs' offer to moot their delisting counterclaims with a letter to the FDA that has not  yet—and may never be—approved.  Even if the FDA accepts the delisting request, nothing bars Plaintiffs from relisting the '115 patent at some point n the future.  

Perplexed that its voluntary patent delisting request did not satisy Par, Avanir shot back in a response brief, saying:

Here, Plaintiffs are at a loss to understand why Par seeks delisting of the ’115 patent, when its continued listing would be intended to protect Par’s own interest in regulatory exclusivity against other generics.  [And, in any case,] Defendants are enjoined from launching their product until 2026 – ten years after the expiration of the ’115 patent.

In any event, what the FDA does or does not do with Plaintiffs’ request is irrelevant to Defendants’ counterclaims.  The statutory remedy is limited to requiring the patent holder—i.e., Plaintiffs—to correct or delete patent information . . . .  The statute does not mandate that the FDA delist the ’115 patent.  Since Plaintiffs have already done what is called for by the statute, Defendants’ counterclaims are moot. . . .  Defendants apparently seek an order requiring Plaintiffs to send another letter to the FDA again requesting delisting of the ’115 patent.  Such an order would be futile.  The FDA has received Plaintiffs initial request and will either delist the patent or not.  A second letter will not change anything.  Indeed, neither Defendants nor Plaintiffs have identified any case where a patent was actually removed from the Orange Book as a result of a delisting counterclaim.  [(Emphasis in oroginal)]

Perhaps not understanding what all the fuss was about given Avanir’s notification to FDA to delist the ‘115 patent information from the Orange Book, the Delaware District Court issued an Order in June 2014 directing the parties in the litigation to “make reasonable efforts to inform [FDA] of the pending request for delisting and of this Court’s request that the FDA provide its views relating to that pending request.” 

Finally, after submitting a joint status report to the Court in which each side sparred with the other and pressed for a dismissal (Avanir) or a delisting Order (Par), the Court issued a delisting Order pursuant to FDC Act § 505(j)(5)(C)(ii)(I)(aa).  In it, the Court recognizes that Par is entitled to such a delisting Order under the statute, but the Court also seems to acknowledge that Avanir can only do so much to “delete” patent information from the Orange Book:

WHEREAS the Court appreciates that Plaintiffs have tried to delete the ‘115 patent from the Orange Book and have failed to do so, yet the law entitles Defendants to an order directing Plaintiffs to try to do so (in this case, to try again to do so); [(Which Avanir did in an August 21, 2014 letter to FDA.)]

IT IS HEREBY ORDERED that Plaintiffs are directed by mandatory injunction under 21 U.S.C. § 355(j)(5)(C)(ii)(I)(aa) to correct within twenty (20) days from the date of this Order and Judgment its improper listing of the '115 patent by submitting to FDA a request enclosing this Order and Injunction to delete the '115 patent from the Orange Book entry for Nuedexta®. . . .  [(Emphasis in oroginal)]

Putting aside for a moment the issue of what it means to delist a patent from the Orange Book, the vigor with which the delisting Order was pursued has perplexed us.  (Though, we note that other strategies pursued by one of the defendants in the case have also perplexed us – see here.)  After all, the ‘115 patent expires more than a decade before the other 180-day exclusivity-bearing patent (i.e., the ‘282 patent) expires on August 13, 2026.  But perhaps an answer lies in a decision by the U.S. Court of Appeals for the Federal Circuit in which that Court ruled that Par’s appeal of the Delaware District Court’s patent infringement decision was premature for lack of a decision on the then-pending patent delisting counterclaim.