Wyeth Holdings Corporation & Ors v Alpharma Ltd

On an application for an interim injunction in a complex patent case, the court should not conduct a mini-trial or attempt to assess validity where the issues are properly triable and reliable technical evidence is absent. The court should proceed to the balance of convenience. Relevant considerations included preservation of the status quo, the likely readiness of the case for trial, and the relative difficulty of assessing loss. An arguable case of patent infringement and passing off was sufficient to justify interim relief where further delay was tolerable and the least unjust course was to maintain existing market conditions pending trial.

The claimants marketed modified-release minocycline capsules under the name Minocin-MR. The defendant proposed to launch a competing product, Sebomin MR, with substantially identical capsule colours and alleged similarities in formulation and presentation.

The claimants sought an interim injunction alleging patent infringement and passing off. The defendant disputed infringement, challenged the patent’s validity by reference to prior art, and contended that the balance of convenience favoured refusal. The central questions were whether the claims were properly triable and, if so, which course best preserved the parties’ positions until trial.

1. Interim approach. The court declined to conduct a mini-trial on patent validity or infringement. Although the strength of the parties’ cases may be considered where one case is clearly very strong and the other very weak, complex patent disputes ordinarily require technical evidence and should not be determined reliably at the interlocutory stage. The approach in Series Five Software [1996] FSR 273 was not retracted, but was applied subject to that limitation.
2. Patent issues. The patent was to be treated as in force, with a non-demurrable validity challenge. In the absence of technical expert evidence, the court could not properly determine the anticipation or obviousness arguments based on Bechgaard and Doryx. The claim that the defendant’s granules were insufficiently spherical was arguable. The claim language concerning retardation in the stomach did not establish pH 1.2 as a mandatory yardstick, and the competing construction of the release requirements was also arguable.
3. Passing off. There was an arguable case that the claimants had built goodwill in the distinctive brown and orange capsule get-up and that use of identical get-up would cause confusion and damage. The case was materially comparable to Hoffman-La Roche v DDSA [1969] FSR 410.
4. Balance of convenience. Applying the familiar approach in American Cyanamid v Ethicon [1975] AC 396, the court considered that either course could cause substantial and difficult-to-quantify loss. The least unjust course was to preserve the status quo because trial could be arranged within about four months, the launch had already been delayed, and further delay was tolerable.
5. The interim injunction was granted in the relief sought by the claimants.