American Cyanamid v Ethicon  AC 396
Guidelines and the issues to be taken into account by the court for the grant of an interim injunction
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 case for patent infringement was not made out. The appellant appealed to the House of Lords.
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 however, set out detailed guidelines with regards to how the courts should deal with the grant of interim injunctions in general.
It was held that (a) it was not the courts’ role to consider conflicting evidence in respect of an interim application. This was a matter for trial. (b) All that was necessary at this stage was that the claimant should show that there was a real issue to be tried. (c) The court should consider whether damages were an adequate remedy for a claimant if an injunction was not granted. If so, an injunction would not be available. (d) If damages were not an adequate remedy, the court should then ask whether the claimant would be able to give an undertaking in damages to the defendant. (e) If it was considered that there was any difficulty regarding the availability of damages on either side, the court should consider the balance of convenience between the parties. (f) If these factors were evenly balanced, the court should consider maintaining the status quo. On the facts of this case, the balance of convenience lay with the appellant and the appeal was allowed.