Federal Circuit Requires “plain and ordinary meaning” to be Consistent With Intrinsic Evidence

The Court of Appeals for the Federal Circuit, in AstraZeneca AB v. Mylan Pharmaceuticals Inc., Case No. 2021-1729 (Fed. Cir., Dec. 8, 2021), reviewed a drug formulation patent that recited a stabilizer concentration “0.001%.” The Court overturned the district court’s “plain and ordinary meaning” construction that used a single significant digit (i.e., 0.0005 to 0.0014%). The Court found that this range of values to be too wide, in view of the test data discussed in the specification and file history. The Court found that only “minor variations” in the stabilizer were consistent with the intrinsic evidence and construed the claim to cover a concentration of 0.00095% to 0.00104%.

The opinion can be found here: https://cafc.uscourts.gov/opinions-orders/21-1729.OPINION.12-8-2021_1875979.pdf