SAN DIEGO — Halozyme Therapeutics has secured a patent infringement injunction against Merck, blocking the manufacture, sale and distribution of the subcutaneous version of its cancer drug Keytruda in eight European markets.
The specialized Dutch patent court in The Hague ruled that Merck infringed Halozyme’s MDASE patent, EP 2,797,622, and ordered Merck’s European marketing authorization holder and global packaging and distribution hub, MSD BV, to halt activities involving Keytruda SC in Belgium, Denmark, France, Ireland, Italy, Sweden, Switzerland and the Netherlands.
The injunction prohibits MSD BV from manufacturing, importing, offering, selling or stocking Keytruda SC in the affected markets. It also prevents the company from facilitating infringement by its affiliates, including through the use of its European marketing authorization.
The court rejected Merck’s arguments that Halozyme’s patent was invalid.
“We’re very pleased the Dutch court recognized the validity and infringement of Halozyme’s MDASE patent EP622 and granted an injunction halting Merck’s launch of Keytruda SC in multiple European markets,” said Mark Snyder, Chief Legal Officer of Halozyme.
“The MDASE technology was developed through years of rigorous research to enable rapid, high-volume subcutaneous drug delivery,” Snyder added.
The ruling does not affect the intravenous version of Keytruda, which remains available to patients and is not covered by Halozyme’s patent or the injunction.
The Dutch decision is the latest development in Halozyme’s ongoing international patent dispute with Merck over the subcutaneous formulation of Keytruda, a cancer immunotherapy.
Halozyme previously obtained a preliminary injunction against Merck in Germany on Dec. 4, 2025, preventing the launch of Keytruda SC in that country.
The company has also filed a patent infringement lawsuit against Merck in federal district court in New Jersey, alleging that the subcutaneous formulation marketed in the United States as QLEX infringes 15 patents related to Halozyme’s MDASE technology.
Those patents stem from research involving nearly 7,000 modifications to human hyaluronidases, enzymes that can facilitate the rapid administration of therapeutic drugs beneath the skin.
Halozyme said its MDASE technology enables high-volume subcutaneous drug delivery, potentially offering an alternative to traditional intravenous administration.
The company emphasized that its MDASE patents are separate from those associated with its ENHANZE drug delivery technology licensing program.
As a result, Halozyme said the patent litigation against Merck will not affect existing ENHANZE licensing agreements or the fees paid by companies using that technology.
The ruling represents another legal development in Halozyme’s efforts to enforce its intellectual property rights surrounding subcutaneous drug delivery technologies.
