Disclosure-Dedication Rule Forecloses Infringement under Doctrine of Equivalents

The disclosure-dedication rule should be one of the strongest rules available to generic drug companies to avoid charges of infringement under the doctrine of equivalents.  A recent case from the District of Delaware involving the blockbuster drug Suboxone® affirms the strength of the rule, but also shows how application of the rule is not always so simple.  Reckitt Benckiser Pharms., Inc. v. Dr. Reddy's Labs. S.A., 2017 U.S. Dist. LEXIS 140633 (D. Del. Aug. 31, 2017).

The patent at issue in the case, U.S. Patent No. 8,017,150, (the ‘150 patent) claims a buprenorphine film strip dosage form made from polyethylene oxide (PEO) and a hydrophilic cellulose polymer (HCP).  The PEO includes both high molecular weight and low molecular weight fractions.  Claim 1 recites:

1. A mucosally-adhesive water-soluble film product comprising:

an analgesic opiate pharmaceutical active; and

at least one water-soluble polymer component consisting of polyethylene oxide in combination with a hydrophilic cellulosic polymer; wherein:

the water-soluble polymer component comprises greater than 75% polyethylene oxide and up to 25% hydrophilic cellulosic polymer;

the polyethylene oxide comprises one or more low molecular weight polyethylene oxides and one or more higher molecular weight polyethylene oxides, the molecular weight of the low molecular weight polyethylene oxide being in the range 100,000 to 300,000 and the molecular weight of the higher molecular weight polyethylene oxide being in the range 600,000 to 900,000; and the polyethylene oxide of low molecular weight comprises about 60% or more in the polymer component.

Dr. Reddy’s developed a formulation that included high and low molecular weight PEO fractions but that substituted polyvinyl pyrrolidone (PVP) for the HCP required by the claim. Reckitt Benckiser admitted that Dr. Reddy’s did not literally infringe claim 1 because its formulation did contain HCP, but argued that Dr. Reddy’s infringed claim 1 under the doctrine of equivalents because PVP and HCP are equivalent.

In response, Dr. Reddy’s argued that the ‘150 patent disclosed that PVP and HCP are alternative water-soluble film-forming polymers, and that the patentee had dedicated PVP to the public by disclosing PVP but not claiming it.  Dr. Reddy’s even pointed to an example where PVP had been combined with PEO to make a film strip.

Reckitt Benckiser argued in response that the example was not enough to dedicate PVP to the public because the example did not use PEO with high and low molecular weight fractions, but the Court was not persuaded.  Citing and quoting the Federal Circuit’s decision in PSC Computer Prod., Inc. v. Foxconn Int'l, Inc., 355 F.3d 1353 (Fed. Cir. 2004), the Court stated:

“One of ordinary skill in the art should be able to read a patent, to discern which matter is disclosed and discussed in the written description, and to recognize which matter has been claimed. … Were the patentee allowed to reclaim some specifically-disclosed-but-unclaimed matter under the doctrine of equivalents, the public would have no way of knowing which disclosed matter infringed and which did not. … Such a reclamation would eviscerate the public notice function of patents and create uncertainty in the law.”

In this case:

“It would be clear to a POSA [Person of Ordinary Skill in the Art] reading the patent as a whole that PVP is disclosed as an alternative to the HCP element of the asserted claims. The strongest evidence that PVP can be used as an alternative to HCP is in the part of the specification where PEO, HCP, and PVP are listed as examples of useful water-soluble film-forming polymers.”

The Court was most persuaded by the fact that HCP and PVP were cited as alternatives in the specification, and believed this disclosure was a clear dedication of PVP to the prior art, if indeed the use of PVP ever had been patentable.  Perhaps the result would have been different if the patent attorney had not disclosed PVP in the specification when originally filed.