Hyaluronidase PH-20 (PH20)

Hyaluronidase PH-20, encoded by the SPAM1 gene, is a glycoside hydrolase enzyme that breaks down hyaluronan, a major glycosaminoglycan component of the extracellular matrix[1][3][5]. In reproductive physiology, PH-20 is expressed on human sperm surfaces where it mediates the penetration of the cumulus cell layer surrounding the oocyte by hydrolyzing hyaluronic acid[7][9]. In oncology, the focus has shifted to its therapeutic use in cancer, particularly via the recombinant PEGylated form (PEGPH20), which enzymatically depletes hyaluronan accumulated in tumor stroma[2][6][8]. This intervention decompresses tumor blood vessels, normalizes interstitial fluid pressure, promotes vascular re-expansion, and facilitates delivery of chemotherapeutics and immune effector cells[2][6][8]. PH-20-mediated HA depletion has shown efficacy in preclinical models by inhibiting tumor growth and enhancing antitumor immunity, especially in HA-rich tumors such as pancreatic ductal adenocarcinoma[6][8]. Expression of hyaluronan and related enzymes thus provides a tumor-selective strategy for modifying the tumor microenvironment, but also poses risks of facilitating metastasis or damaging normal tissues if not appropriately controlled[2][6].

Other names

Sperm adhesion molecule 1 (SPAM1)HYAL5Sperm surface protein PH-20Human hyaluronidase PH20

Enzymatic degradation of hyaluronan (hyaluronic acid) in the extracellular matrix, leading to remodeling of tumor stroma, lowered interstitial fluid pressure, increased vascular permeability, enhanced drug delivery, and modulation of immune cell infiltration[2][4][6][8].