Enhanze is Halozyme’s drug delivery platform based on the company’s recombinant human hyaluronidase enzyme (rHuPH20). “Enhanze enables biologics to be delivered as a simple subcutaneous injection,” said Gregory I. Frost, Ph.D., president and CEO, Halozyme. Pfizer will be able to combine rHuPH20 with its biologics directed to up to six targets.In a 2007 paper (it's behind a paywall), Frost explains the rationale behind the development of rHuPH20, a soluble enzyme that breaks down hyaluronan in intercellular spaces. In doing so, injection of volumes larger than 2mL is made possible, which opens up the door for self-injection of a wider array of biologic drugs, such as antibodies. These typically can't be concentrated enough to be delivered in under 2mL injections and need to be delivered by IV. Frost puts it concisely:
Intravenous infusions require skilled intervention and are, thus, typically performed in a physician’s office or hospital. In contrast, local injections of chronic therapies can permit family members or patients themselves to administer the mediation outside the hospital setting.It's a good move for Pfizer and great win for Halozyme.