MSD ordered to pull injectable Keytruda from sale in Europe

MSD has been rocked by a court judgment ordering it to stop manufacturing and selling its subcutaneous formulation of cancer immunotherapy Keytruda in eight European markets.

It's the latest twist in an ongoing legal dispute between MSD and Halozyme Therapeutics in which the latter is claiming that Keytruda SC (pembrolizumab and berahyaluronidase alfa) infringes its intellectual property.

The specialised Dutch patent court in The Hague has concluded that MSD – known as Merck & Co in the US and Canada – is infringing one of Halozyme's European patents (EP 2,797,622) covering MDASE, a technology platform that uses modified human hyaluronidases to make infused drugs deliverable by injection.

Specifically, the lawsuit focuses on the berahyaluronidase alfa component – developed by Alteogen – that makes it possible to deliver larger volumes of drug material and improve dispersion and absorption through the skin.

The new judgment has rejected MSD's argument that the '622 patent is invalid and orders the company to desist from supplying Keytruda SC in Belgium, Denmark, France, Ireland, Italy, Sweden, Switzerland, and the Netherlands.

Halozyme previously sued MSD in Germany and was granted a preliminary injunction in December 2025, blocking the launch of Keytruda SC in that market. So far, MSD has commented on the new verdict. Meanwhile, Halozyme is also suing for patent infringement in the US federal district court in New Jersey.

Keytruda SC – which is known as Keytuda Qlex in other markets, including the US – is a key growth product for MSD, accounting for $463 million of total Keytruda sales of $8.4 billion in the second quarter of this year.

That means it still lags well behind the intravenous formulation, but is expected to be a major factor limiting the impact of biosimilar competition when the original Keytruda formulation starts to lose patent protection, starting in 2028.

"We're very pleased the Dutch court recognised 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 Halozyme's chief executive, Mark Snyder.

"The MDASE technology was developed through years of rigorous research to enable rapid, high-volume subcutaneous drug delivery," he added, while stressing the case has no bearing on his company's Enhanze hyaluronidase PH20 platform, which is used in 10 products across 100 markets worldwide.