A court has ordered Merck & Co. to suspend sales of its subcutaneous Keytruda formulation in several European Union member states. The interim injunction, reported by FirstWord Pharma, extends across multiple national markets and creates immediate compliance questions for Merck's European oncology business.

The FirstWord notice does not identify the deciding court, the case reference, the plaintiff, or the date of the order. Counsel and industry analysts watching the matter should treat the specifics as pending confirmation until a public version of the ruling or a court docket filing surfaces.

What does the headline tell us about the case?

Keytruda (pembrolizumab) is the cornerstone of Merck's oncology franchise and one of the highest-revenue medicines worldwide. The subcutaneous ("SC") formulation delivers the same active ingredient as the original intravenous product through a different administration route, typically a shorter injection time.

Merck developed the SC version in part to extend the franchise's commercial life as European patent and regulatory exclusivities on the IV product approach their cliff. A court-ordered sales halt in even a portion of the EU would target that extension strategy directly. FirstWord's phrasing — "multiple EU countries" — suggests a multi-jurisdictional injunction rather than a single country pause.

What legal basis typically supports such an order?

The headline report does not disclose the statutory or patent ground for the injunction. EU pharmaceutical litigation of this type usually proceeds on one of three tracks:

• National patent infringement actions under the Enforcement Directive (2004/48/EC), often heard by specialised patent courts in member states.
• Disputes over supplementary protection certificates governed by Regulation (EC) No 1610/96 and the SPC manufacturing waiver.
• Unified Patent Court proceedings, where the relevant claim is a European Patent with unitary effect.

Without the order's operative language, practitioners cannot yet assess whether the court acted on an SPC question, an underlying patent right, or a procedural bar.

Why must practitioners look at territorial reach?

A single national injunction in the EU does not, on its own, shut down sales across all 27 member states. Cross-border enforcement requires either:

• separate actions and national orders in each targeted jurisdiction, or
• proper service and recognition under the Brussels Ia Regulation (1215/2015), or
• a Unified Patent Court order covering participating member states.

FirstWord's reference to "multiple EU countries" implies that the plaintiff has secured parallel relief in more than one jurisdiction or has used a forum capable of multi-state effect.

What changes for Merck and competitors?

Three practical points stand out for in-house and outside counsel:

• Affected Merck subsidiaries must notify wholesalers and hospital pharmacies of the suspension and arrange product-recall logistics consistent with EU GDP rules.
• Biosimilar and generic manufacturers targeting pembrolizumab should reassess launch timing country by country, since the injunction's scope outside the named states remains uncertain.
• Payers and hospital procurement teams that had begun shifting patients from IV to SC pembrolizumab will need clinical guidance on reverting to the IV product.

What to watch next

Two near-term signals will determine how the injunction reshapes the European pembrolizumab market:

• Publication of the operative order, or a procedural notice that names the deciding court, the parties, and the patents or SPCs in dispute.
• Any Merck application for a stay pending appeal, alongside procedural moves in unaffected member states.

Until those documents appear, both the territorial reach and the appellate prospects of the injunction will remain open questions.