Federal Circuit Clarifies Analysis for Preliminary Injunction in Patent Cases

The Federal Circuit recently issued a precedential opinion clarifying, in two respects, the proper analysis for deciding whether to grant a preliminary injunction in patent cases.

In Titan Tire Corp. v. Case New Holland, Inc., No. 2008-1078 (Fed. Cir. June 3, 2009), the court first noted that the basic standard for issuance of a preliminary injunction in any type of case is the four-factor test set forth recently by the Supreme Court in Winter v. Natural Resource Defense Council, 129 S. Ct. 365, 374 (2008): “[a] plaintiff seeking a preliminary injunction must establish [1] that he is likely to succeed on the merits, [2] that he is likely to suffer irreparable harm in the absence of preliminary relief, [3] that the balance of equities tips in his favor, and [4] that an injunction is in the public interest.” (emphasis added). Prior to Winter, each circuit had its own variation of the test, but the Federal Circuit acknowledged that the Winter test “is now the definitive one,” and that the movant bears the burden of persuasion on these factors.
Second, the court addressed the patent-specific issue of the parties’ respective burdens concerning the invalidity at the preliminary injunction stage. In a nutshell, the Federal Circuit held:

• The trial court must weigh the available evidence for and against validity;
• If there is a “substantial question of invalidity,” then the patentee has by definition not shown that he is likely to succeed on the merits;
• A “substantial question of invalidity” exists where “the alleged infringer has presented an invalidity defense that the patentee has not shown lacks substantial merit”; and
• While the “clear and convincing evidence” standard for proving invalidity does not apply at the preliminary injunction stage, the judge should consider that the infringer must meet that standard at trial in deciding whether, at the preliminary injunction stage, a substantial question of invalidity exists.