Sanofi-Aventis (“Sanofi”) sued Fresenius Kabi and others (“Defendants”) for infringement of U.S. Patents Nos. 8,927,592 (the “’592 patent”) and 5,847,170 (the “’170 patent”) after the generic manufacturers filed ANDAs to market generic versions of Sanofi’s cabazitaxel drug. Cabazitaxel, marketed as Jevtana®, is used for the treatment of drug-resistant prostate cancer. The ’170 and 592 patents cover the compound cabazitaxel and methods of using it, respectively.
While the district court case was pending, the Patent Trial and Appeal Board (PTAB) instituted an inter partes review (IPR) of the claims of the ’592 patent, and ultimately invalidated claims 1-5 and 7-30. During the course of the IPR, the PTAB also denied a motion filed by Sanofi to amend certain claims. Sanofi appealed the PTAB’s decision on its motion to amend, but did not appeal the PTAB’s decision as to claims 7, 11, 14-16 and 26. Instead, Sanofi filed a statutory disclaimer of those claims. Shortly after Sanofi filed its statutory disclaimer, the district court held that a case or controversy remained between the parties despite the disclaimer and entered an order invalidating Sanofi’s disclaimed claims.
On appeal, Sanofi challenged the district court’s determination that a case or controversy existed over the disclaimed claims. Defendants responded that, depending on the outcome of the pending PTAB appeal, Sanofi could amend its claims and assert them against Defendants in the future. Defendants argued that, under such circumstances, they needed the district court’s decision in this case to preserve possible issue preclusion or claim preclusion defenses that might be asserted in future litigation against Sanofi. In other words, Defendants worried that, should the district court’s decision be vacated on appeal, Sanofi could assert closely related, but slightly amended new claims against the Defendants, forcing them to effectively re-litigate the same validity issues.
The Federal Circuit rejected Defendants’ arguments and held that the disclaimer mooted any controversy over them as soon as it was entered. In its analysis, the court emphasized that “an actual controversy must be extant at all stages of review,” and a patentee loses the ability to assert claims once they are cancelled even if the litigation is already pending. Thus, the district court did not have the authority to invalidate the claims after Sanofi entered its disclaimer. Moreover, Defendants’ argument that Sanofi might assert amended claims in the future rests on a “hypothetical appellate reversal or vacatur and remand of the Board’s inter partes review decision,” which is insufficient to establish a case or controversy at present. In any event, Defendants will still have an opportunity to raise their preclusion defenses at the district court if and when Sanofi asserts amended claims in the future.
Practice tip: Although the Federal Circuit made clear that a party cannot maintain a district court action involving disclaimed claims, it also confirmed that patentees may still be subject to the preclusive effects of decisions invalidating those claims in future litigation. Thus, parties to litigation should be cognizant that disclaimer of previously invalidated claims will not necessarily provide a clear path to litigate closely related claims.
Sanofi-Aventis U.S., LLC v. Dr. Reddy's Laboratories, Inc., Nos. 2018-1804, 2018-1808, 2018-1809, slip op. (Fed. Cir. Aug. 14, 2019).