Halozyme Therapeutics, Inc. Announces Closing of $32.1 Million Private Financing

SAN DIEGO, May 31 /PRNewswire-FirstCall/ -- Halozyme Therapeutics, Inc. , a biopharmaceutical company developing and commercializing recombinant human enzymes, today announced that it has closed the previously reported private placement of 3,500,000 shares of common stock with New River Management V, LP ("New River") at a price of $9.17 per share, for aggregate gross proceeds of approximately $32.1 million. The per share sale price represents a $0.22 per share premium to the closing price of Halozyme common stock on the date that the parties executed the definitive stock purchase agreement relating to the sale of the shares. Halozyme has agreed to file a registration statement with the SEC on or before November 1, 2007 covering the resale of the shares of common stock issued in this private placement. New River is a private equity fund managed by Third Security, LLC and affiliated with Halozyme's largest stockholder, Randal J. Kirk. Mr. Kirk is also a member of Halozyme's Board of Directors.

About Halozyme Therapeutics, Inc.

Halozyme is a biopharmaceutical company developing and commercializing recombinant human enzymes for the drug delivery, palliative care, oncology, and infertility markets. The company's portfolio of products is based on intellectual property covering the family of human enzymes known as hyaluronidases. The company's Enhanze(TM) Technology is a novel drug delivery platform designed to increase the absorption and dispersion of biologics. In addition, the company has received FDA approval for two products: Cumulase(R) and Hylenex, for use as an adjuvant to increase the absorption and dispersion of other injected drugs and fluids. The Company also has a number of different enzymes in its portfolio that are targeting significant areas of unmet need.

Contacts: Halozyme Contact David A. Ramsay Chief Financial Officer (858) 794-8881 dramsay@halozyme.com Investor Relations Contact Don Markley Lippert/Heilshorn & Associates (310) 691-7100 dmarkley@lhai.com Media Contacts Karen Sparks / Joleen Schultz Mentus (858) 455-5500, x230/x215 karen@mentus.comjschultz@mentus.com

CONTACT: David A. Ramsay, Chief Financial Officer of HalozymeTherapeutics, Inc., +1-858-794-8881, dramsay@halozyme.com; or investors,Don Markley of Lippert-Heilshorn & Associates, +1-310-691-7100,dmarkley@lhai.com, for Halozyme Therapeutics, Inc.; or media, Karen Sparks,+1-858-455-5500, ext. 230, karen@mentus.com, or Joleen Schultz,+1-858-455-5500, ext. 215, jschultz@mentus.com, both of Mentus for HalozymeTherapeutics, Inc.

Web site: http://www.halozyme.com/