Assessment and Implication of the Allergic Sensitivity to a Single Dose of Recombinant Human Hyaluronidase Injection

Animal-extracted injectable hyaluronidases have been used safely for more than 50 years to increase the dispersion and absorption of coadministered drugs and fluids; however, concern still exists about the allergic and immunological risks of these products. Hylenex recombinant, a novel formulation of recombinant human hyaluronidase, has been developed as an alternative to these animalderived hyaluronidases. Because recombinant human hyaluronidase is a human (nonforeign) protein manufactured into a purer preparation than the animal extracts, it is expected to convey reduced allergic and immunologic risks. The recombinant human hyaluronidase product was well tolerated in this double-blind, placebo-controlled, single-dose study. No allergic reactions were observed among the 100 volunteer subjects who were injected intradermally. These findings supported the US Food and Drug Administration approval of the recombinant human hyaluronidase product.