[Edaily Reporter Kim Jin-soo] #It has been confirmed that Altogen’s partner, Merck (MSD), has secured a complete victory in a lawsuit filed in the UK regarding Halozime’s European patent. With Halozime voluntarily revoking its UK patent, the obstacle to the sale of Keytruda Qurex—the subcutaneous (SC) formulation of Keytruda—has been removed in the UK, following the U.S.

UK Patent Court Orders MSD to Pay Halozyme’s Legal Costs

On the 17th, it was confirmed that the UK Patent Court ordered Halozyme to pay indemnity costs in a lawsuit related to Halozyme’s European Patent (UK) No. 2,797,622 (hereinafter “EP 622”).

This UK dispute began when MSD filed an invalidity action against Halozyme’s EP 622 patent. In response to MSD’s preemptive attack, Halozyme filed a counterclaim alleging that MSD had infringed its patent. During the proceedings, MSD argued that Halozyme had failed to present clear evidence supporting its claim of patent infringement. Consequently, the UK court also repeatedly requested that Halozyme specifically detail the alleged infringement and submit relevant evidence.

Halozime argued that infringement was evident based on experimental results obtained during the German litigation. It also repeatedly requested extensions of the deadline for submitting evidence, stating that it was conducting additional experiments for the UK lawsuit. However, in late March of this year, just two days before the final deadline for submitting evidence, Halozime suddenly announced its intention to agree to the revocation of the EP 622 patent in the UK, effectively abandoning the lawsuit.

Subsequently, MSD filed a motion for summary judgment with the court, requesting an official confirmation that Halozyme’s infringement claims lacked substantive grounds. In response, the court ruled that since Halozyme’s patent itself had been revoked, the infringement claims automatically lapsed, and therefore there was no need to issue a separate summary judgment.

In the subsequent final ruling, the court largely accepted MSD’s arguments. Judge Hacon, who presided over the case, ruled in MSD’s favor, stating, “Although Halozyme claimed that its infringement allegations were justified based on German experimental results, it failed to submit the complete data from those experiments or the results of additional experiments conducted in the United Kingdom to the court.”

In particular, the court found that Halozyme lacked sufficient reasonable grounds to prove infringement as of the time it filed its counterclaim. According to the judgment, the court assessed the infringement claims as “speculative, weak, or thin,” lacking substantive evidence.

Ultimately, the court found that Halozyme’s counterclaim constituted an abusive practice of litigation that went beyond the scope of a typical patent dispute and ordered Halozyme to pay MSD indemnity costs, which are higher than standard litigation costs.

The pharmaceutical and biotech industries view this ruling as a case demonstrating that a party alleging patent infringement must bear significant legal and financial burdens if it files an aggressive lawsuit without sufficient scientific grounds and objective evidence. Amid intensifying competition in the global biopharmaceutical market over hyaluronidase-based formulation conversion technology, this ruling has reaffirmed that objective data and verifiable evidence are of paramount importance in patent litigation.

Furthermore, this outcome in the UK is highly significant as it could influence ongoing litigation across Europe.

Sales Royalties Expected in the UK Following the U.S. Market Following

this UK court decision, the obstacle to sales of Keytruda Qurex

in the UK

has been removed,

following the U.S. market

. According to the NHS, approximately 14,000 patients in the UK with 14 types of cancer—including lung, breast, head and neck, and cervical cancers—begin treatment with Keytruda each year.

According to a May report by global market research firm Fortune Business Insights, the UK market for Keytruda is estimated at approximately $1.38 billion (2.08 trillion won). This represents a massive 4.17% of the global Keytruda market. As MSD is accelerating the transition of Keytruda from an intravenous formulation to a subcutaneous injection formulation, the royalties that Altheogen is expected to receive are projected to increase further.

Previously, the U.S. Patent Trial and Appeal Board (PTAB) also rejected Halozyme’s patent in a Patent Gestation Review (PGR) filed by MSD against Halozyme. In addition to the litigation between Halozyme and MSD, the U.S. Patent and Trademark Office (USPTO) dismissed the request to initiate a hearing on an Interparticular Review (IPR) filed by Halozyme targeting Altheogen’s process patent.

Consequently, Alteogen is expected to receive the remaining $1 billion (approximately 1.5 trillion won) in milestone payments from the sale of Keytruda Qurex within the next three to four years. Alteogen is projected to secure sales royalties from Keytruda Qurex in the U.S. and the U.K.

An Alteogen official stated, “We will further accelerate our efforts to secure additional partnerships for ALT-B4 going forward.”