Berahyaluronidase alfa is a recombinant human hyaluronidase that temporarily increases tissue permeability by degrading hyaluronan in the extracellular matrix, thereby facilitating the absorption and dispersion of co-administered subcutaneous drugs like pembrolizumab.

In biochemical assays, Berahyaluronidase alfa acts as a spreading factor by catalyzing the hydrolysis of the beta-1,4-glycosidic bonds in hyaluronan. This enzymatic digestion results in a transient decrease in the viscosity of the interstitial ground substance, thereby lowering the resistance to the flow of injected therapeutic fluids [1].