Dutch court blocks Merck's subcutaneous Keytruda sales in eight European countries after Halozyme patent win

A Netherlands court issued an injunction that stops Merck from marketing its subcutaneous formulation of Keytruda, known as Keytruda Qlex, in eight European markets.

The ruling follows a patent infringement claim by Halozyme, which says Merck's product uses Halozyme's technology for rapid under‑skin delivery of large biologic molecules. The court agreed that Merck's drug infringes those patents.

Halozyme has been pursuing similar actions in Germany and is also challenging Merck in the United States. The decision strengthens Halozyme's negotiating position and could lead to a licensing deal or other settlement.

The injunction does not affect Merck's standard intravenous Keytruda, but it could impact the company's strategy for subcutaneous immunotherapy in Europe.