PTAB Invalidates Halozyme Patent in Keytruda Dispute
In a key victory for Merck, the Patent Trial and Appeal Board invalidated a Halozyme patent related to Keytruda Qlex™ technology, finding the claims unpatentable for lack of written description and enablement.
The US Patent Trial and Appeal Board (PTAB) delivered a significant win for Merck, issuing a final written decision that invalidates all challenged claims of a Halozyme patent for its PH20 hyaluronidase technology. The Board found the patent unpatentable for lacking adequate written description and enablement, siding with Merck’s arguments in the post-grant review. However, the PTAB rejected Merck's separate arguments that the claims were obvious.
This decision is a key event in the broader intellectual property battle over Keytruda Qlex™, a recently approved Merck drug that uses the Halozyme technology. The invalidation weakens Halozyme's position in parallel district court litigation and offers a potential playbook for challenging broad biotech patents based on limited disclosed data. For counsel in the life sciences sector, the PTAB’s consistent reasoning across several related decisions in this dispute highlights the vulnerability of such claims. Market participants should now watch for a potential appeal to the Federal Circuit and monitor three newly instituted IPRs against other Halozyme patents in this ongoing dispute.