复宏汉霖HLX319皮下Phesgo生物类似药推进I期，但并非新披露里程碑

Henlius, a subsidiary of China's Fosun Pharma, has begun developing a subcutaneous (SC) formulation biosimilar using its own hyaluronidase enzyme. The move is seen as the first attempt of its kind, as no commercialized SC biosimilar using hyaluronidase exists due to patent barriers.
According to the pharmaceutical and biotech industry on the 19th, Henlius is conducting a Phase 1 trial of "HLX319," a biosimilar of Roche's Phesgo. "Due to patent restrictions related to hyaluronidase, there has been no approved case of an SC combination biosimilar," Henlius said. "HLX319 is based on our independently developed hyaluronidase, 'Henozyme.'" Phesgo is a product combining Herceptin and Perjeta into one, applying Halozyme's SC platform technology.
Henlius's trial is interpreted as targeting entry into the Chinese and European markets. The company referenced not only Chinese regulatory standards but also European biosimilar guidelines, and is using Phesgo for European sale (EU-Phesgo) as the reference drug. The European Medicines Agency (EMA) and China's National Medical Products Administration (NMPA) are known to classify hyaluronidase not as a core ingredient but as a modifiable excipient. However, even if regulatory approval is obtained, like other biosimilars, patent issues regarding dosage and administration methods must additionally be resolved for commercialization.
By contrast, the U.S. Food and Drug Administration (FDA) considers hyaluronidase a core ingredient, treating a product as a separate drug rather than a biosimilar if it does not use the identical substance. Failing to obtain biosimilar approval means high clinical and development costs, and reduced economic viability as the product cannot receive benefits such as pharmacy substitution even after commercialization. This is also why Korean platform company Alteogen explained that "under U.S. regulations, developing a biosimilar of the Keytruda SC formulation (Qrex) is impossible."
Henozyme is a hyaluronidase-based SC formulation conversion platform that Henlius unveiled last year. The company emphasized that it designed Henozyme in consideration of existing platform companies' patent portfolios (Halozyme with 5, Alteogen with 4, and Kangju with 2). However, during the development process, the company voiced the technical difficulty of developing its own hyaluronidase, saying, "The modifiable amino acid positions to exert efficacy while avoiding existing patents amount to less than 10% of the total." Samsung Bioepis, which originally developed its own SC formulation conversion technology, was also confirmed to have based the substance it uses on Halozyme's "Enhanze," unlike its cultivation and purification processes.