Legal Case Summary
American Cyanamid v Ethicon [1975] AC 396
Guidelines and the issues to be taken into account by the court for the grant of an interim injunction
Facts
The appellant was a company that held a patent for artificial absorbable surgical sutures. The respondent was a company that intended to launch a suture to the British market which the appellant claimed was in breach of its patent. At first instance, the appellant was granted an injunction preventing the respondent’s use of the type of suture at issue until the trial of the patent infringement. On appeal, the Court of Appeal discharged the injunction on the basis that the claimant had not made out a prima facie case of infringement. The appellant appealed to the House of Lords.
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Issues
The issue on these facts was primarily the extent of any substantive claim necessary for the grant of an interim injunction. The House of Lords also set out detailed guidelines with regards to how the courts should deal with the grant of interim injunctions in general.
Decision/Outcome
The House of Lords held that the court should first ask whether there is a serious question to be tried. It should generally leave disputes of fact and difficult questions of law for trial. If damages would adequately compensate the claimant and the defendant could pay them, an injunction should normally be refused.
If damages would not adequately protect the claimant, the court considers whether the claimant’s undertaking in damages would adequately protect the defendant if the injunction proved unjustified. If there is doubt about the adequacy of damages on either side, the court weighs the balance of convenience. Where the considerations are evenly balanced, preserving the status quo is prudent.
The House allowed the appeal and restored the interim injunction. The balance of convenience favoured preserving the position until trial. The House did not decide whether the patent had been infringed.
