Astrazeneca AB & Anor v Glenmark Pharmaceuticals Europe Limited

On an interim-injunction application, the American Cyanamid guidelines remain binding. Where there is real doubt about the adequacy of damages for either side, the court must assess all relevant circumstances and choose the course likely to cause the least irremediable prejudice. It must take account of harm caused by events during the interim period which may manifest later, including a change in the status quo before a form-of-order hearing.

In a short-lived pharmaceutical patent dispute, where multiple at-risk generic entry makes the comparative risks uncertain, preservation of the status quo will ordinarily be prudent. A generic intending to launch at risk must clear the path in sufficient time, including by seeking justified expedition where necessary. Launching during a validity trial without awaiting judgment may weigh against disturbing the status quo.

AstraZeneca owned supplementary protection certificates relating to dapagliflozin. Glenmark had obtained a marketing authorisation and intended to launch a generic dapagliflozin product at risk while revocation proceedings concerning the certificates awaited judgment.

The Patents Court dismissed AstraZeneca’s application for an interim injunction until the form-of-order hearing following the validity judgment: [2025] EWHC 748 (Pat). It held that damages would adequately compensate AstraZeneca, although damages would be harder to assess for Glenmark and the NHS.

On AstraZeneca’s expedited appeal, further evidence showed that at least two further generic suppliers would enter rapidly if Glenmark were permitted to launch. The central question was whether, pending the form-of-order hearing, the balance of the risk of injustice favoured an injunction.

1. Appeal allowed. The court granted an interim injunction restraining Glenmark until the conclusion of the form-of-order hearing. That order did not determine any later application for an injunction pending an appeal from the validity judgment.

2. The court remained bound by the guidelines in American Cyanamid, [1975] AC 396. Adequate damages will normally preclude an injunction, but damages need not be a perfect remedy. Where their adequacy is genuinely uncertain, the court must consider all relevant circumstances and select the course least likely to cause irremediable prejudice.

3. The new evidence materially changed the position. It established that at least three generic suppliers would enter before the form-of-order hearing and that price competition and a downward price spiral would follow quickly. The judge had also misread AstraZeneca’s evidence concerning the likelihood that it would reduce its actual price and its difficulty in restoring that price because of NHS resistance. There was therefore real doubt as to whether damages would adequately compensate AstraZeneca, even before the form-of-order hearing.

4. The judge had further erred by not considering the consequential harm after that hearing. Entry by Glenmark and the other generics would change the status quo, prejudice a later application for an injunction pending appeal, and extend the risks of price erosion and consequential operational changes. There was likewise real doubt as to the adequacy of damages for Glenmark and the NHS, but no reliable basis for deciding which side faced the greater uncompensated loss.

5. Given the short period involved, the prudent course was to preserve the status quo. Glenmark had not cleared the path adequately: it had not supported its request for an earlier trial with commercial reasons or sought the necessary justified expedition, and it proposed to launch during the validity trial without awaiting judgment. Those matters reinforced the need for an orderly resolution of the dispute.

• Court of Appeal (Civil Division): Allowed AstraZeneca’s appeal and granted an interim injunction pending the conclusion of the form-of-order hearing.
• High Court, Patents Court: Michael Tappin KC, sitting as a Deputy High Court Judge, dismissed AstraZeneca’s application for an interim injunction: [2025] EWHC 748 (Pat).