In three petitions filed on the same day in 2013, styled Amneal v. Supernus, Amneal filed what appears to be the first challenge of Orange Book listed pharmaceutical patents that led to institution followed by a final decision in which the patent owner prevailed.[1]  Several lessons are apparent from a review of the first successful defense of the Orange Book listed pharmaceutical patents in Amneal v. Supernus.

What Was Persuasive to the Courts Was Not Always Persuasive to the Board

In earlier litigation preceding the IPRs of Amneal v. Supernus, a parent patent had already been upheld as valid over the same prior art used in the IPR petitions by two different district courts, one of which had been upheld on appeal. To try to prevent the IPRs from being instituted, the patent owner elected to file a preliminary response. The Patent Owner’s Preliminary Response included extensive exhibits from the parallel litigation explaining why the references did not suggest a formulation which combined only an immediate release (IR) and delayed release (DR) component in a certain ratio to achieve a once-a-day administration, as well as many exhibits related to secondary considerations to rebut obviousness.

Despite the court’s prior rulings of validity on a similar patent over the same prior art, the Board instituted the IPRs. In particular, the Board disagreed with the courts as to what was taught by the primary reference, finding “that Ashley ’854 discloses an IR/DR-only formulation as one of seven possible combinations of immediate-release, sustained-release, and/or delayed-release agents.” Although the Board acknowledged that the primary reference encompassed combinations outside the scope of the claim, the Board was not persuaded by teaching away arguments, given the limited number of possibilities.

As to the secondary considerations, the Board felt that the petitioner deserved an opportunity to challenge the evidence that other parties had faced in the earlier litigation. Specifically, the Board stated in its decision to institute that “detailed consideration of Supernus’s secondary consideration evidence may not be undertaken until Amneal has had an opportunity to test it.” Here, the Board departed from other panels in not addressing the secondary considerations fully on the merits at the institution stage, possibly because Amneal was not a party to the earlier litigations where the evidence had been presented.

Ultimately, in the final decision, the Board found persuasive a new argument not presented in litigation that the secondary reference did not clearly teach a DR component, even when the phrase “delayed release” (DR) was given its broadest reasonable interpretation:

“Because we credit Dr. Rudnic’s testimony, we agree with Supernus that Sheth’s secondary loading portion is not a ‘delayed release’ portion. A ‘delayed release’ format, when that term is construed to mean ‘release of a drug at a time other than immediately following oral administration,’ specifically excludes formats that result in release of drug starting immediately after oral administration. To conclude otherwise would read the phrase ‘delayed release’ out of the claim.”

This was a new argument developed specifically for the IPR. Thus, patent owners, even if they have been successful in prior litigation, need to consider that different arguments may be required to defend against IPRs. The Board may take a different view of the prior art, in addition to applying a different claim construction standard (broadest reasonable interpretation) and a different evidentiary standard (preponderance of the evidence). Patent owners must carefully consider the different playing field in an IPR when selecting what arguments to present to the Board.

The Patent Owner’s Preliminary Response Was Effective to Eliminate Some Grounds of Unpatentability

While the Board did institute the IPRs on a single ground of obviousness over two references, the Board found certain arguments from the patent owner persuasive in the preliminary response, which led to a decision not to institute on obviousness over a single reference. The Board found that “Amneal has not demonstrated a reasonable likelihood that claim 1 is unpatentable for obviousness over Ashley ’932 [alone].” When weighing whether to file a preliminary response, patent owners are advised to consider the possibility that it may help to at least reduce the scope of institution, even if it does not prevent institution on all grounds.

Prosecuting a Continuation Application During the IPR May Be Better Than Trying to Amend During an IPR

Given the difficulties of amending during an IPR, the patent owner in Amneal v. Supernus took advantage of a pending continuation to obtain allowance of related claims during the IPR. Patent Owner filed an Information Disclosure Statement to fully apprise the Examiner of the status of the IPR and the Board’s decision to institute. After considering the information and the differences in the claims over the prior art, the Examiner allowed the application before a final decision was reached in the IPR, leading to a new patent (US Patent No. 8,709,478), which was added to the Orange Book.

The claim newly presented to the Examiner in the continuation (claim 1 of the issued patent) reads as follows:

1. A method for treating rosacea in a mammal in need thereof, comprising administering an oral pharmaceutical composition consisting of (i) an immediate release formulation (IR) comprising about 30 mg doxycycline; (ii) a delayed release formulation (DR) comprising about 10 mg doxycycline; and (iii) a pharmaceutically acceptable excipient selected from the group consisting of binder, disintegration agent, filling agent, surfactant, solubilizer, stabilizer, plasticizer, lubricant, enteric polymers, and combinations thereof; and (iv) optionally, a controlling coat, overcoating layer, a core, and combinations thereof, wherein doxycycline is the sole active ingredient and the total amount of doxycyline in the composition is about 40 mg.

For comparison to the above claim, one of the patents undergoing IPR had the following independent composition claim:

1. An oral pharmaceutical composition consisting of (i) an immediate release formulation (IR) comprising about 30 mg doxycycline; a delayed release formulation (DR) comprising about 10 mg doxycycline; and optionally, (iii) one or more pharmaceutically acceptable excipients.

Keeping a continuation pending offers the patent owner an advantage of being able to freely amend claims without having to be concerned about either intervening rights or the restrictions placed by the Board upon amendments during IPRs.

Although the number of IPRs overall may be leveling off, the number of IPR challenges of bio/pharma patents is rapidly increasing, having almost doubled in 2015 over 2014 before the fiscal year end has been reached. See “Bio/Pharma IPR Challenges Nearly Double in 2015”. The lessons above may be helpful to bear in mind when facing these challenges.


[1] An earlier set of IPRs involving US Patent Nos. 5,997,915, 6,011,040, 6,673,381 and 7,172,778  resulted in a final decision of invalidity for a pharmaceutical food supplement, but Amneal v. Supernus is believed to be the first IPR challenge of Orange Book listed patents to reach a final decision in which the patent owner prevailed. For full disclosure, the author served as lead counsel in the Amneal v. Supernus IPRs.