In 2006, the US Supreme Court reversed years of jurisprudence by eliminating the presumption of irreparable harm in patent litigations,1 which previously had resulted in virtually automatic grants of injunctions to prevailing patent holders. Since then, courts have been applying the same four factors in considering injunctive relief that are used in other forms of litigation: (1) the likelihood of a plaintiff prevailing on the merits; (2) the existence and extent of irreparable harm; (3) the balance of the equities; and (4) what serves the public interest.

In medical device cases, the public interest factor is often paramount and has resulted in frequent denials of injunctive relief. Nevertheless, there are cases in which preliminary injunctions are granted. 2 Various considerations drive the outcomes in these cases. Here are three which companies in this field should bear in mind when bringing or defending a preliminary injunction motion.

Preliminary injunction requests

Even though filing a preliminary injunction is not a prerequisite to obtaining permanent injunctive relief, courts may consider a patentee’s decision not to bring the earlier motion as evidence of no irreparable harm in determining whether to issue an injunction at the conclusion of the case. 3 Timing is also critical to the public interest analysis. The longer an accused medical device has been on the market, the more opportunity for defendants to present evidence of surgeon preference or improved patient outcomes associated with the accused product. In contrast, an accused product nascent to the market may be considered “too new to harm the public interest by the grant of preliminary relief.” 4

Availability of substitute devices

Having the same procedural applications or indications as the accused product is another consideration. The presence of non-infringing market alternatives typically weighs in the patentee’s favor and can counterbalance any concern that an injunction will limit the breadth of physician choice.

Strong causal nexus

Recent trends requiring patentees to establish a sufficiently strong causal nexus between the claimed patent features and consumer demand for the accused product can significantly impact the imposition of injunctive relief. Patentees must establish an asserted patented feature is at least one of several that contribute to consumer purchasing decisions or that the feature’s absence would render a product significantly less desirable. Unlike pharmaceutical patents, for example, where an infringing drug often represents the entire patented invention, medical device patent claims are often directed to specific improvements or components of an overall apparatus. There may be challenges with directly tying the patented features to consumer demand for the overall product or showing that the features are central to the operation of the accused device.

The considerations for preliminary injunction in the medical device context should encourage companies in this space to strategically select which patents and specific claims to assert in a motion for a preliminary injunction. Even if an accused product is likely to infringe numerous patents and patent claims, a strategic approach can help heighten the chances of success in the quest for injunctive relief.