Federal Circuit Finds Prosecution History Estoppel Prevents Coverage of Equivalent Since Amendment Was Foreeseable Equivalent

In Duramed Pharmaceuticals, Inc v Paddock Labritories, Inc., 644 F3d 1376, 99 USPQ2d 1388 (Fed. Cir. 2011), Duramed (now known as Teva Women’s Health Inc.) owns U.S. Patent No. 5,908,638 (‘638 patent.), which is directed to estrogen pharmaceutical compositions.  When originally filed, original independent claim 1 recited a conjugated estrogen pharmaceutical composition “coated with a moisture barrier coating,” and original dependent claim 7 limited “said moisture barrier coating” to one that “comprises ethylcellulose.”  During prosecution, the examiner rejected both claims for obviousness.  However, after an interview, the Examiner indicated that if the limitation of claim 7 was included the independent claim 1, it would be allowed. Duramed amended claim 1 to include the limitation, and the claim was allowed.  Thus, claim 1 of the issued ‘638 patent claimed pharmaceutical compositions for hormonal treatment of pre-menopausal, post-menopausal, and menopausal disorders with “a moisture barrier coating comprising ethylcellulose.”

In 2009, Duramed brought suit against Paddock under 35 U.S.C. §271(e)(2) for infringement of  the ‘638 patent. Paddock had proposed in an Accelerated New Drug Application for a generic version of Duramed’s hormone replacement utilizing polyvinyl alcohol (PVA) for a moisture barrier coating (marketed as Opadry AMB.)  Duramed asserted that the generic version infringed claims 1, 4, and 6-8 under the doctrine of equivalents because Paddock’s proposed generic product uses a polyvinyl alcohol (“PVA”) MBC, marketed as Opadry AMB. Paddock moved for summary judgment of noninfringement, arguing that Duramed was barred by amendment-based prosecution. Continue reading

Federal Circuit Rejects Ensnarement Defense and Finds that the Ensnarement Defense is an Issue of Law

In DePuy Spine, Inc. v. Medtronic, Inc., Civ. Case Nos. 90 USPQ2d 1865 (Fed. Cir. 2009), DePuy owns U.S. Pat. No. 5,207, 678 (the ‘678 patent).  The ‘678 patent is directed to a medical device that is a pedicle screw used in spinal surgeries.  DePuy sued Medtronic, accusing Medtronic of infringing the ‘678 patent with Medtronic’s Vertex pedicle screws.  The U.S. District Court for the District of Massachusetts denied Medtronic’s ensnarement defense, found that Medtronic engaged in litigation misconduct, with both decisions being appealed before the Federal Circuit Court.  Additionally, DePuy cross-appeals from the District Court’s granting of Medtronic’s motion for judgment as a matter of law (JMOL) of no willful infringement and from the denial of DePuy’s motion for a new trial for reasonable royalty damages. 

In a prior appeal, the Federal Circuit Court upheld the District Court’s granting of summary judgment as per Medtronic not literally infringing the ‘678 patent with Medtronic’s Vertex pedicle screws.  However, the Federal Circuit Court reversed the District Court’s granting of summary judgment of noninfringement under the doctrine of equivalents.  In the prior appeal, the Federal Circuit Court remanded the case because it found a question of fact existed on whether the Vertex screw’s conical shape was insubstantially different from the ‘678 patent’s screw having a limitation in claim 1 of the patent reciting a “spherically-shaped portion.  In the remanded case, Medtronic asserted an “ensnarement” defense against the doctrine of equivalents issue, wherein the Medtronic asserted that the scope of equivalency of the ‘678 patent would “ensnare” the prior art.  Continue reading