Decision: Dr. Reddy’s Labs. S.A. v. Invidior UK Ltd., IPR2019-00328, Paper 19 (P.T.A.B. June 3, 2019)

Background:  Indivior UK Limited (“Patent Owner”) owns U.S. Patent No. 9,687,454 B2 (“the ’454 patent”). The ’454 patent relates to “self-supporting film dosage forms which provide a therapeutically effective dosage” of buprenorphine and naloxone. ’454 patent, 1:20–25; 4:67–5:4. The ’454 patent contains fourteen claims. Id. at 24:25–26:15. Claim 1 is reproduced below:

  1. An oral, self-supporting, mucoadhesive film comprising:

(a) about 40 wt % to about 60 wt % of a water-soluble 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 the film is mucoadhesive to the sublingual mucosa or the buccal mucosa;

wherein the weight ratio of (b):(c) is about 4:1;

wherein the weight ratio of (d):(b) is from 2:1 to 1:5; and

wherein application of the film on the sublingual mucosa or the buccal mucosa results in differing absorption between buprenorphine and naloxone, with a buprenorphine Cmax[1] from about 0.624 ng/ml to about 5.638 ng/ml and a buprenorphine AUC from about 5.431 hr*ng/ml to about 56.238 hr*ng/ml; and a naloxone Cmax from about 41.04 pg/ml to about 323.75 pg/ml and a naloxone AUC from about 102.88 hr*pg/ml to about 812.00 hr*pg/ml.

Claim 13 recites a method for treating opioid dependence in a patient in need thereof comprising sublingually or buccally administering the mucoadhesive film of claim 1 to a sublingual or buccal mucosal tissue of the patient. Although Claim 13 depends on claim 1, it is a different statutory class from claim 1 and hence might be considered an independent claim.

During prosecution, Patent Owner amended the claims originally pending in the application resulting in the ’454 patent to overcome multiple obviousness rejections. For example, the Examiner rejected all pending claims as obvious over Oksche et al., WO 2008/025791 A1, published March 6, 2008 (“Euro-Celtique”). IPR2019-00328, Paper 19, at 10 (P.T.A.B. June 3, 2019). In response, Patent Owner cancelled or amended all of the pending claims but also argued that Euro-Cletique did not teach every element of the claimed subject matter. Id. at 10-11.

In a final Office Action, the Examiner again rejected the pending claims as obvious over Euro-Celtique, and in view of Fuisz et al., WO 03/030883 A1, published April 17, 2003 (“Fuisz”), European Medicines Agency Initial Marketing-Authorization Document for Suboxone® Tablet, 1–42 (2006) (“EMEA”), and the Suboxone® Sublingual Tablets Package Insert. Id. at 11-12. The Examiner found that Euro-Celtique taught many elements recited in the pending claims and that any further experimentation to achieve the claimed invention would have been obvious to a person of ordinary skill in the art.  Id.

Patent Owner responded by again amending the pending claims and filing a RCE. Id. at 12. The Examiner once again rejected the pending claims over Euro-Celtique, finding that any optimization of the claimed pH/dosage would have been routine. Id. After an interview, the Examiner issued a Notice of Allowability with an Examiner’s Amendment that amended claim 11 to include “acidic” before “buffer.” Id.

Patent Owner, not satisfied, withdrew the application from issuance, and filed a second RCE; the RCE amended then-pending independent claim 11 (which became claim 1 of the ’454 patent) as follows:

11. An oral, self-supporting, mucoadhesive film comprising:

(a) about 40 wt % to about 60 wt % of a water-soluble 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 the film is mucoadhesive to the sublingual mucosa or the buccal mucosa;

wherein the weight ratio of (b):(c) is about 4:1;

wherein the weight ratio of (d):(b) is from 2:1 to 1:5; and

wherein application of the film on the sublingual mucosa or the buccal mucosa results in differing absorption between buprenorphine and naloxone, with a buprenorphine Cmax[1] from about 0.624 ng/ml to about 5.638 ng/ml and a buprenorphine AUC from about 5.431 hr*ng/ml to about 56.238 hr*ng/ml; and a naloxone Cmax from about 41.04 pg/ml to about 323.75 pg/ml and a naloxone AUC from about 102.88 hr*pg/ml to about 812.00 hr*pg/ml ACU from about 5.431 hr*ng/ml to about 56.238 hr*ng/ml..

Patent Owner added “an” before “acidic buffer” and at the end of the claim, changed the recited AUC values and added new units (hr*pg/ml instead of “hr*ng/ml).  The Examiner subsequently issued a second Notice of Allowability, allowing those amended claims, and the ’454 patent issued.

Following issuance, Dr. Reddy’s Laboratories S.A. and Dr. Reddy’s Laboratories, Inc. (“Petitioners”) filed a petition to institute an inter partes review (“IPR”) of claims 1–3 and 5–14 (“the challenged claims”) of the ’454 patent. Petitioners contended that the challenged claims were unpatentable as obvious over “Euro-Celtique and Fuisz in view of the Suboxone® PDR, EMEA, and the FDA IIG Database.” IPR2019-00328, Paper 21, at 6 (P.T.A.B. June 3, 2019).   

The Petitioners furthermore indicated to the PTAB that there was also ongoing litigation involving the ’454 patent. Id. at 3.

Issue:

When does the PTAB exercise its discretion under 35 U.S.C. § 325(d) to deny an IPR petition where the petition is based on the same or substantially the same prior art and arguments presented during prosecution?

Outcome:

Here, the Board denied Dr. Reddy’s petition. Section 325(d) indicates that the PTAB has broad discretionary power when deciding whether to institute an IPR. Specifically, it provides that “[i]n determining whether to institute or order a proceeding under this chapter . . . [t]he Director may take into account whether, and reject the petition or request because, the same or substantially the same prior art or arguments previously were presented to the Office.” Whenever a patent owner argues that a petition should be denied because an Examiner already considered prior art, the PTAB applies several non-exclusive factors, known collectively as the Becton Dickinson factors, after Becton, Dickinson & Co. v. B. Braun Melsungen AG, IPR2017-01586, Paper 8, at 17–18 (P.T.A.B. Dec. 15, 2017) (informative); those factors include:

a) the similarities and material differences between the asserted art and the prior art involved during examination;

b) the cumulative nature of the asserted art and the prior art evaluated during examination;

c) the extent to which the asserted art was evaluated during examination, including whether the prior art was the basis for rejection;

d) the extent of the overlap between the arguments made during examination and the manner in which Petitioner relies on the prior art or Patent Owner distinguishes the prior art;

e) whether Petitioner has pointed out sufficiently how the Examiner erred in its evaluation of the asserted prior art; and

f) the extent to which additional evidence and facts presented in the Petition warrant reconsideration of the prior art or arguments.

IPR2019-00328, Paper 19, at 9. See also, NHK Spring Co., Ltd. v. Intri-Plex Techs., IPR2018-00752, Paper 8, at 11–18 (PTAB Sept. 12, 2018) (precedential) (analyzing the Becton Dickinson factors). 

Here, the PTAB grouped the Becton Dickinson factors into two categories. The first category included factors (a)–(d), which factors address the extent to which the Examiner relied on the asserted prior art during prosecution, and the similarities between the arguments made during prosecution and in the IPR petition. IPR2019-00328, Paper 19, at 15. Of the prior art references asserted in the IPR, Euro-Celtique and the EMEA reference were considered by the Examiner during prosecution. Id. According to the PTAB, the Suboxone® Package Insert (asserted by the Examiner) and the Suboxone® reference (asserted by Petitioners) were substantially the same. Id. at 16. The only asserted reference that was not before the Examiner was FDA IIG, but the PTAB found “that an analysis of the disclosure of FDA IIG suggests hindsight reconstruction and adds little, if anything, to the obviousness analysis.” Id. at 17.

The second category of Becton Dickinson factors included (e) and (f), which both question whether the petition asserted new arguments or ways to view the prior art. Id. at 18. Petitioners contended that the Examiner erred in evaluating Euro-Celtique, among other references. In particular, Petitioner urged that a Delaware litigation opinion, Reckitt Benckiser Pharms., Inc. v. Watson Labs., Inc., 2016 WL 3186659 (D. Del. June 3, 2016), demonstrated that the Examiner erred in evaluating the asserted prior art. IPR2019-00328, Paper 19, at 18. Flatly rejecting that argument, the PTAB noted that the Delaware opinion involved different patents, claims, and prior art not asserted in the current IPR. Id. Also, the Delaware opinion was cited to and considered by the Examiner in the ’454 patent prosecution. Id.

Petitioners also argued that Patent Owner disavowed arguments made during prosecution of the ’454 patent. Id. at 18–20. First, Petitioners contended that Patent Owner’s arguments in a challenge of a non-involved patent that was related to Euro-Celtique contradicted their statements regarding the same prior art during prosecution of the ’454 patent.  Id. The PTAB rejected characterizing Patent Owner’s argument as a disavowal, noting that the Examiner during the ’454 patent prosecution recognized and expressly stated what the prior art taught. Id.

The second alleged disavowal stemmed from inconsistent arguments between the ’454 patent prosecution and the IPR proceeding. Id. Rejecting this argument, the PTAB found the Petitioners’ argument lacked clarity. Id. Petitioners also did not help themselves by their “terse characterization” of Patent Owner’s three-page argument in a single sentence, their failure to explain the alleged inconsistency, and their unsupported argument that statements made in different contexts involving different claims show that the Examiner erred. Id. at 19-20.

Furthermore, Petitioners asserted that their expert declaration, not before the Examiner in the ’454 prosecution but submitted during the IPR, explained how a person of ordinary skill in the art would have interpreted the prior art. Id. at 20. That declaration was supposed to show how the Examiner erred during prosecution of the ’454 patent. Id. The PTAB, however, did not find the declaration to be persuasive, noting that the new information in the expert’s declaration would not warrant reconsideration of the same or substantially the same art and arguments which were before the Examiner during the ’454 patent prosecution. Id. 

After balancing the Becton Dickinson factors, the PTAB concluded that “the same or substantially the same prior art or arguments that Petitioners assert[ed] in the IPR were presented to the Office during examination of the ’454 patent.” Id at 20–21. Therefore, the PTAB exercised its discretion under § 325(d) and denied institution of the petition. Id.

Takeaways:

The PTAB is less likely to institute an IPR when an Examiner has already considered the asserted prior art, particularly if, after careful review of the Becton Dickinson factors, the PTAB concludes that an Examiner was correct in its review of that prior art during original prosecution. Even though there are six Becton Dickinson factors, they do not make up an exclusive list and, moreover, the PTAB will not necessarily review each of them individually. Indeed, the PTAB may group the factors together into categories and adopt a more holistic approach.

In this decision, the PTAB concluded, after holistically analyzing at least the six Becton Dickinson factors, that exercising its discretion under 35 U.S.C. § 325(d) to deny institution was appropriate because this petition presented prior art that was the same or substantially similar to the prior art reviewed by the Examiner during prosecution. Manifestly, how the Becton Dickinson factors cut will depend on all facts and circumstances of an individual proceeding. However, if Petitioner asserts new arguments or additional information related to art that was before the Examiner, then the PTAB may be more likely to institute the IPR based upon those new arguments or new information.

That raises the question, how does one differentiate between the same art when used in an IPR petition and that had been considered by the Examiner?  Lessons to be gleaned from this denial include:

  1. Use at least one reference that was not mentioned in the prosecution history.
  2. Show that the “new” reference adds a teaching not considered by the Examiner and thus is not cumulative to the prior art considered during prosecution.
  3. Avoid, if relying on previously considered prior art, asserting the same arguments used before the Examiner.
  4. Consider, if relying on the same reference or argument raised during prosecution, submitting an expert declaration to establish that the Examiner had misunderstood or misapplied how a person of ordinary skill in the art would view that reference or argument.
  5. Explain precisely, if arguing that the patent owner made a clear disavowal, why the patent owner’s statements are contradictory and why that inconsistency amounts to disavowal.
  6. From the patent owners’ point of view, consider conducting thorough prior art searches before prosecution and disclose the references to the Examiner. That may make prosecution more difficult, but it could be helpful if subsequent litigation ensues of a fully vetted patent.

Also, estoppel against the Petitioner does not arise in the absence of a Final Written Decision. 35 U.S.C. § 315(e). In this case, there was no Final Written Decision, so Petitioners would not be estopped from raising arguments presented in the IPR petition in a subsequent district court litigation. While the PTAB’s denial of institution of the IPR might be considered by a court if the same arguments were raised during litigation, the fact of the denial, alone, may not be fatal to Petitioners’ litigation positions.

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