Out of 14 initiated PGR proceedings, 9 have reached final determinations—all resulting in the invalidation of the contested claims.
Following earlier rejections of the 324 and 320 variants, the 313 variant patent has also been blocked, effectively clearing the path to removing Halozyme's patent obstacles.
Alteogen (196170) is effectively clearing the hurdles posed by Halozyme’s patents surrounding its subcutaneous (SC) formulation technology. With the U.S. Patent Trial and Appeal Board (PTAB) issuing additional patentability rejections for two more Halozyme patents, all nine cases for which Merck (MSD) filed Post-Grant Review (PGR) petitions have now reached a final determination—with every single one resulting in a rejection of the contested claims.
Merck has initiated a total of 14 PGR proceedings. In the nine cases that have reached a final decision, the PTAB has, without exception, denied the patentability of the claims at issue. Merck is currently commercializing its subcutaneous version of Keytruda, which utilizes Alteogen’s ALT-B4 technology, and is concurrently engaged in patent infringement litigation with Halozyme in the United States.
Final Determinations Rise from 7 to 9: 313-Variant Patent Also Stalled
Previously, the PTAB had already rejected the patentability of claims in seven cases. With the addition of these two latest rulings, the total number of finalized cases has risen to nine.
These two latest cases share a commonality: they involve patents covering variations at the amino acid 313 position within Halozyme's modified PH20 technology. This follows earlier rejections of patents covering modifications at positions 324 and 320, extending the streak of unfavorable outcomes for Halozyme.
Merck had argued that the scope of the PH20 variants claimed in these patents was overly broad and unsupported by actual experimental data or the patent specifications themselves. The PTAB sided with Merck in these two cases, ruling the remaining claims in the proceedings as unpatentable.
Nine Consecutive Rejections: Substantial Patent Barriers to Keytruda SC Lifted
Merck is actively commercializing its subcutaneous Keytruda formulation using Alteogen’s ALT-B4. Halozyme is currently suing Merck in the U.S. District Court for the District of New Jersey for patent infringement, and the patents subject to these PGRs are central to that ongoing litigation.
While PTAB decisions are limited to the specific claims challenged in each PGR and are subject to potential further proceedings, this does not mean all of Halozyme’s PH20-related patents have been invalidated.
To date, final decisions have been reached in nine out of the 14 initiated PGR cases, with the PTAB rejecting the patentability of the claims in every instance. The final rulings on the remaining five cases are still pending. Furthermore, three separate Inter Partes Review (IPR) petitions filed by Merck were initiated last month and are currently underway.
※ This report references information introduced on the Naver blog ‘J’s Value Investment Story,’ with independent verification conducted against U.S. Patent Trial and Appeal Board (PTAB) rulings and U.S. Patent and Trademark Office (USPTO) records.
