Pfizer, Inc., et al. v. Ranbaxy Laboratories, Limited, et al.
Claim Was Invalidated for Failure to Comply with Section 112, Paragraph 4.
The CAFC affirmed the finding of infringement of Pfizer’s U.S. Pat. No. 4,681,893 (the ‘893 patent) but reversed the district court’s ruling with respect to U.S. Pat. No. 5,273,995 (the ‘995 patent) and found Claim 6 of the ‘995 patent invalid.
The technology of the ‘995 patent is related to atorvastatin calcium, commonly known as the cholesterol-lowering drug Lipitor. The relevant ‘995 claims can be simply stated as follows:
1. Atorvastatin acid; or a atorvastatin lactone; or pharmaceutically acceptable salts thereof.
2. A compound of claim 1 which is atorvastatin acid.
6. The hemicalcium salt of the compound of claim 2.
As the district court noted, Claim 2 does not include pharmaceutically acceptable salts of atorvastatin acid. Thus, Claim 6 did not properly incorporate subject matter by reference and specify a further limitation of Claim 2 as required by Section 112, paragraph 4, However, the district court refused to invalidate the claim, citing that the defect was a matter of form and not substance. In essence, the district court declined to find that the drafting problem was sufficient to render the claim invalid if read consistently with its meaning to those skilled in the art.
The CAFC recognized that Claim 6 could have been properly drafted as dependent from Claim 1. However, the CAFC also stated that courts “should not rewrite claims to preserve validity.” As Claim 6 failed to specify a further limitation of the subject matter of Claim 2, Claim 6 was held invalid for failure to comply with section 112, paragraph 4.
Applicants are required “to satisify certain requirements before obtaining a patent” and invalidating a claim for failure to comply with section 112, paragraph 4 “does not exalt form over substance.”