No Second Bite at the Apple for Apotex in Acular Litigation; Roche Prevails Again

Roche Palo Alto LLC v. Apotex, Inc., No. C05-02116-MJJ (N.D. Cal. 2007)

Guest post by Robert S. Dailey

Apotex suffered a loss last week in its effort to relitigate the validity of U.S. Patent No. 5,110,493, which covers Roche's ketorolac tromethamine (KT) ophthalmic solution (i.e., Acular®).  The U.S. District Court for the Northern District of California granted Roche's motion for summary judgment.

Apotex had previously filed an ANDA for a 0.5% solution of KT solution.  Roche sued.  After a couple of trips to the Federal Circuit, including a petition by Apotex for rehearing in light of KSR, the patent was found to be valid, enforceable, and infringed.  Apotex’s last hope was a petition for certiorari.  But wait a moment . . .

Apotex later developed a 0.4% KT solution, and submitted a second ANDA for that formulation.  Roche again sued.  Last week, the district court ruled in Roche's favor, holding that claim preclusion and issue preclusion barred nearly all of Apotex's arguments and that Apotex had failed to establish an equitable defense based on the reverse doctrine of equivalents.

The reverse doctrine of equivalents is an equitable defense that permits an accused infringer to escape liability when his device performs a similar function to the patented invention in such a substantially different manner that it would be inequitable to hold him liable.  According to the Federal Circuit's 1991 Scripps Clinic case, application of the doctrine "requires that facts specific to the accused device be determined and weighed against the equitable scope of the claims, which in turn is determined in light of the specification, the prosecution history, and the prior art."

Apotex argued that the 0.4% KT solution is substantially different from the 0.5% KT solution because the former does not depend on micelle formation to stabilize the active ingredient.  Nevertheless, the legal standard nowhere asks the court to compare the infringing device to the patentee's device.  Rather, the infringing device is compared against the objective teachings of the patent document and its file wrapper.  The intrinsic record of the Roche patent never discusses micelle formation.  Moreover, the specification even discloses an example showing a 0.4 % KT solution.  This proved fatal to Apotex's argument.  There is one slight wrinkle, though:  in the earlier trial, the district court had cited micelle formation as a fact supporting the patent's utility.  But Scripps Clinic permits the court to look only at the intrinsic record.  A court opinion from prior litigation is not part of that intrinsic record.

Either claim preclusion or issue preclusion barred the rest of Apotex's arguments.  In light of KSR, the district court did devote a bit more page-space to thinking through the appropriate means of handling Apotex's obviousness argument.  If KSR resulted in a "major change[] in the law," issue preclusion may not apply to the court's prior determination that the patent is nonobvious.  The court seemed to suggest, however, that KSR created no such "major" change, but only undercut the Federal Circuit's occasional overly-rigorous application of the TSM test.  In the end, though, the court punted on this issue.  In this instance, claim preclusion dealt the knockout blow.

Claim preclusion, after all, bars relitigation even when there has been a major change in the law.  But the later case must involve the same claim.  Apotex argued that its 0.4% solution presents the court with a different claim.  Indeed, it is not the same product that Apotex proffered in the prior litigation.  But in patent actions, "changes unrelated to the limitations in the claim of the patent would not present a new cause of action for purposes of claim preclusion."  Although Apotex had varied the concentrations of four ingredients in producing its new formulation, those concentrations still fell squarely within the ranges specified in the Roche patent.  Under this standard, it seems that a defendant could only succeed by raising strong arguments of non-infringement.  Apotex was unable to do that in this case.

The facts of the case do cast some doubt on whether claims encompassing the 0.4% KT solution are indeed valid.  If Apotex had known in 2003 what it knew in 2005, they may have stood a better chance of proving invalidity of claims that encompassed concentrations that failed to produce stabilizing micelles.  Based on what we now know, those broader claims may indeed have been invalid for lack of utility and/or enablement.  But for Apotex, that train had already left the station.