The rHuPH20 Enzyme

WASHINGTON /PRNewswire-FirstCall/ — Halozyme Therapeutics, Inc. a development stage biopharmaceutical company focused on the development and commercialization of recombinant human enzymes, announced that results from new preclinical studies with Halozyme’s recombinant human PH20 (rHuPH20) hyaluronidase enzyme were presented at the 2005 American Society of Cataract & Refractive Surgery (ASCRS) Symposium on Cataract, IOL and Refractive Surgery, American Society of Ophthalmic Administrators (ASOA) Congress on Ophthalmic Practice Management, and the Clinical and Surgical Staff Program in Washington, D.C.

The data were presented at the ASCRS Innovators Session by Herbert E. Kaufman, MD, Boyd Professor of Ophthalmology and Pharmacology & Experimental Therapeutics at the Louisiana State University Health Sciences Center School of Medicine in New
Orleans.

Dr. Kaufman presented preclinical safety and pharmacology animal studies demonstrating that when viscoelastic agents commonly used in cataract surgery were placed in the eyes of animals, injection of Halozyme’s rHuPH20 enzyme into the front of the eye significantly reduced the incidence and severity of intraocular pressure (IOP) rises.

Such pressure “spikes” are believed to occur when viscoelastic materials used in the surgical procedure clog up the eye’s drainage canals and prevent fluid from properly draining out of the eye, a process that can potentially result in permanently dilated pupils,
persistent glare, pain, and discomfort, and retinal and optic nerve vascular occlusion. Dr. Kaufman’s data also showed that injection of rHuPH20 into the front of the eye caused no toxicity to the corneal endothelial cells in the eye.

“These findings further support an innovative new application of the rHuPH20 enzyme and warrant further investigation,” said Gregory Frost, PhD, Halozyme’s Vice President and Chief Scientific Officer. “Minimizing surgical complications from cataract surgery could be helpful for a large number of patients, given that more than 13 million cataract surgeries are performed worldwide every year.”

Halozyme’s hyaluronidase (rHuPH20) is a highly purified, recombinant form of a naturally occurring human enzyme and is being investigated for its ability to break down hyaluronic acid (HA), the space-filling “gel”-like substance that is a major component of tissues throughout the body. The rHuPH20 enzyme can degrade most viscoelastic agents used in clinical practice and therefore could potentially be developed for use as a viscoelastic “antidote” in patients undergoing cataract surgery, in which viscoelastic
agents are used in every case to prevent damage to the cornea.