Duramed Pharmaceuticals, Inc. v. Paddock Laboratories, Inc.
644 F.3d 1376
| Fed. Cir. | 2011Background
- Duramed owns U.S. Patent 5,908,638 claiming conjugated estrogens with a moisture barrier coating (MBC) to inhibit moisture degradation.
- The patented composition is a solid oral dosage form for peri-/post-menopausal hormonal treatment and must include an ethylcellulose MBC per the amended claim 1.
- Duramed amended claim 1 in 1998 to recite a moisture barrier coating comprising ethylcellulose after an examiner’s rejection, narrowing the claim scope before issuance.
- Paddock sought summary judgment of noninfringement under prosecution history estoppel, arguing Duramed cannot invoke doctrine of equivalents for PVA MBC (Opadry AMB) used in Paddock’s generic product.
- Pre-amendment references, including Colorcon’s PCT (disclosing PVA MBCs like Opadry AMB) and other prior art (Groppenbächer patent, articles, and pre-1998 invoices), were relied on to show foreseeability of the alleged equivalent.
- The district court granted summary judgment, concluding Duramed failed to rebut the estoppel; Duramed appealed.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Whether prosecution history estoppel bars the doctrine of equivalents | Duramed argues estoppel can be rebutted if the alternative was unforeseeable | Paddock contends presumption applies and Duramed failed to rebut | Presumption applies; Duramed failed to rebut |
| Whether PVA MBCs were foreseeable in the field of pharmaceutical compositions at the time of amendment | Duramed contends PVA was not known as suitable MBC for conjugated estrogens | Paddock relies on Colorcon PCT and related references showing foreseeability | Foreseeable as a matter of law based on Colorcon PCT disclosure |
| Whether Colorcon PCT alone suffices to establish foreseeability of PVA MBCs | Duramed asserts PCT lacks data showing suitability for the claimed drugs | Paddock argues disclosure of PVA as MBC in the field is enough for foreseeability | Colorcon PCT renders PVA MBCs foreseeable; further data not required |
Key Cases Cited
- Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722 (2002) (prosecution history estoppel framework)
- Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 493 F.3d 1368 (Fed. Cir. 2007) (Foreseeability standard in patent amendments (Festo X))
- Schwarz Pharma, Inc. v. Paddock Labs., Inc., 504 F.3d 1371 (Fed. Cir. 2007) (field-of-invention foresees equivalents)
- Glaxo Wellcome, Inc. v. Impax Laboratories, Inc., 356 F.3d 1348 (Fed. Cir. 2004) (foreseeability shown by prior art disclosures)
- Honeywell Int'l, Inc. v. Hamilton Sundstrand Corp., 523 F.3d 1304 (Fed. Cir. 2008) (foreseeability does not require perfect data)