## Facts

- Merck manufactured and sold enalapril sodium tablets (VASOTEC®) since 1983 and held compound patents on enalapril sodium, but not a process patent for its manufacturing method.
- Apotex obtained U.S. Patent Nos. 5,573,780 and 5,690,962, claiming a process for making a stable solid enalapril sodium dosage form by reacting enalapril maleate with an alkaline sodium compound and excipients under conditions avoiding a clear solution intermediate.
- Merck conceived and reduced its enalapril sodium tableting process to practice in the United States before Apotex’s asserted invention date and used the process continuously in commercial production from 1983 onward.
- Merck disclosed aspects of the formulation in foreign materials, including a French publication (1988) and a Canadian product monograph (1992) distributed in large quantities.
- In Canadian patent litigation, Merck’s manufacturing process was described and demonstrated at trial; Apotex’s employee alleged conception of Apotex’s later-patented process shortly after that disclosure.
- Apotex sued Merck for infringement in the Northern District of Illinois; Merck asserted invalidity under 35 U.S.C. § 102(g) (pre-AIA) based on Merck’s prior U.S. invention without abandonment, suppression, or concealment.
- The district court granted summary judgment for Apotex on infringement but granted summary judgment for Merck that Apotex’s asserted claims were invalid under § 102(g); Apotex appealed the invalidity ruling.

## Issues

1. Whether Apotex’s process patent claims were invalid under 35 U.S.C. § 102(g) because Merck made the invention first in the United States and had not abandoned, suppressed, or concealed it.
2. Whether the “suppressed or concealed” inquiry under § 102(g) may consider foreign publications and foreign trial disclosures when assessing an earlier U.S. inventor’s conduct.
3. Whether failure to seek a process patent, limited public disclosure, or incomplete regulatory disclosure can establish suppression or concealment under § 102(g) on this record.

## Decision

- The Federal Circuit affirmed summary judgment that the asserted claims of the ’780 and ’962 patents were invalid under 35 U.S.C. § 102(g).
- Apotex did not dispute on appeal that Merck invented first in the United States and did not abandon the process; the appeal turned on suppression or concealment.
- The court held that Merck did not suppress or conceal the invention, emphasizing Merck’s continuous commercial use since 1983 and its disclosures through foreign publications and Canadian trial testimony and demonstration.
- The court rejected the argument that § 102(g) restricts the suppression/concealment analysis to U.S.-only activities; foreign evidence could be used to show lack of suppression or concealment.
- The court found no genuine dispute of material fact on suppression or concealment and upheld invalidity as a matter of law.

## Legal Principles

- Under pre-AIA 35 U.S.C. § 102(g), a later patent is invalid if another made the invention first in the United States and had not abandoned, suppressed, or concealed it.
- Suppression or concealment can be intentional or inferred from an unreasonable delay in making the invention publicly known or pursuing patent protection, but the inference may be rebutted by commercial use and public disclosure.
- Continuous commercial exploitation of an invention is evidence inconsistent with abandonment and may rebut an inference of suppression or concealment.
- The statutory requirement that the invention be “made in this country” concerns the location of the prior invention, not the geographic location of evidence used to prove or disprove suppression or concealment.
- An inventor has no per se duty to file a patent application; failure to patent, without more, does not establish suppression or concealment where disclosure and use negate the inference.

## Conclusion

The Federal Circuit held Apotex’s process claims invalid under pre-AIA § 102(g) because Merck invented the process first in the United States and, through continuous commercial use and public disclosures (including abroad), did not abandon, suppress, or conceal the invention.


Apotex USA, Inc. v. Merck & Co., 254 F.3d 1031 (Fed. Cir. 2001)