Alteogen’s ALT-B4 patent push gets Europe boost amid Halozyme setback

(Courtesy of Alteogen)

Korea’s Alteogen said Tuesday the European Patent Office (EPO) intends to grant a substance patent covering ALT-B4 (berahyaluronidase alfa), its hyaluronidase enzyme used in Merck’s subcutaneous (SC) version of Keytruda (pembrolizumab).

The announcement came the same day the U.S. Patent Trial and Appeal Board (PTAB) invalidated key claims of Halozyme Therapeutics’ U.S. Patent No. 12,018,298 in a post-grant review filed by Merck & Co., known as MSD outside the United States and Canada.

It is the third Halozyme MDASE (modified hyaluronidase) patent to receive a final invalidity ruling in MSD’s challenges, according to Alteogen. The company said Merck has filed post-grant review (PGR) petitions against 15 Halozyme MDASE patents.

Halozyme has accused Merck’s subcutaneous Keytruda, which uses Alteogen’s ALT-B4, of infringing its modified hyaluronidase patents. The dispute includes a federal lawsuit in New Jersey and a German injunction blocking sales of Keytruda SC in Germany.

Alteogen said it already holds U.S. patent protection for ALT-B4 through 2043. It said the EPO decision covers ALT-B4 itself and that it will proceed with national validation procedures in Europe.

The German injunction is based on a separate European Halozyme patent and remains in place. Alteogen said it is not a party to that case.