Dutch Court Bars Merck's Subcutaneous Keytruda Across Multiple EU Markets in Halozyme Patent Victory

A Dutch court has granted Halozyme Therapeutics a preliminary injunction blocking the manufacture and sale of Merck's subcutaneous formulation of Keytruda, known as Keytruda SC, across multiple European Union markets. The order, issued in the Netherlands, extends its reach to Belgium, Denmark, France, Ireland, Italy, Sweden, and Switzerland, where Halozyme had counterclaimed for infringement in February 2026. The ruling centers on Halozyme's MDASE subcutaneous drug delivery technology, protected under European Patent No. 2 797 622.

This is the second major European injunction Halozyme has secured against Merck's Keytruda SC. A German court issued the first in December 2025, following a hearing in which the Munich Regional Court found imminent infringement and halted Merck's launch activities in Germany. Merck has appealed that German decision, with a hearing scheduled for November 19, 2026. The Dutch case was heard at the end of July 2026, with the court delivering its ruling within the expected three-month window. Halozyme originally filed suit in April 2025 in U.S. District Court in New Jersey, alleging Merck used its patented technology to develop Keytruda SC without authorization.

The injunctions do not affect the intravenous formulation of Keytruda, which remains available to patients in the affected markets. Merck has filed revocation actions against Halozyme's EP 622 patent in multiple European jurisdictions including the UK, France, Germany, the Netherlands, Denmark, Sweden, and Switzerland, challenging the underlying patent's validity as it contests the injunctions.