The Federal Circuit has disagreed with Apotex that a district court erred in failing to find non-infringement under the reverse doctrine of equivalents and upheld the district court decision granting summary judgment that Roche’s US Patent No. 5,110,493 is valid and infringed by Apotex’s ANDA for generic version of anti-inflammatory eye drug Acular LS. Acular LS is an ophthalmic solution containing ketorolac tromethamine marketed by Allergan for the treatment of inflammation associated with glaucoma, conjunctivitis and eye surgery.
The ‘493 patent claims an ophthalmic formulation comprising a non-steroidal inflammatory drug, a quaternary ammonium preservative, and the non-ionic surfactant, octoxynol 40 (O40). In its Appeal, Apotex did not dispute that its ANDA falls within the literal scope of claim 1 of the ‘493 patent but instead argued that the district court erred in failing to find non-infringement under the reverse doctrine of equivalents. The Federal Circuit explained that the reverse doctrine of equivalents (“RDOE”) “is an equitable doctrine designed to prevent unwarranted extension of the claims beyond a fair scope of the patentee’s invention.” The court referred to Supreme Court’s RDOE test, set forth in the Graver Tank case:
Where a device is so far changed in principle from a patented article that it performs the same or a similar function in a substantially different way, but nevertheless falls within the literal words of the claims, the reverse doctrine of equivalents may be used to restrict the claim and defeat the patentee’s action for infringement.
Apotex argued that the ‘principle’ of the ‘493 patent is “the use of O40 in an amount sufficient to cause the formation of micelles and thereby provide robust stability to the formulation by preventing interactions between ketorolac tromethamine and benzalkonium chloride.” The Federal Circuit disagreed and found no support for this principle in the specification, prosecution history or prior art. According to the Federal Circuit, Apotex relied exclusively on the declaration of its expert and agreed that Apotex failed to make out a prima facie case of non-infringement under the reverse doctrine of equivalents, and therefore summary judgment of infringement was proper. The Federal Circuit also agreed with the district court that Apotex’s invalidity arguments were barred by claim preclusion (e.g., res judicata).