HTI-501 Data Support Commencement of Phase 2 Portion of Clinical Trial

Subcutaneous Administration of Conditionally Active Recombinant Human Cathepsin Was Well Tolerated

SAN DIEGO, Jan. 31, 2012 /PRNewswire/ -- Halozyme Therapeutics, Inc. (NASDAQ: HALO) today presented interim results from the Phase 1 proof-of-concept and local tolerability study of HTI-501 (an investigational, conditionally active recombinant human cathepsin) at the 8th World Congress of the International Academy of Cosmetic Dermatology in Cancun, Mexico. Data from the study support commencement of the Phase 2 portion of the clinical trial. The Phase 1/2 trial of HTI-501 is in female patients with moderate to severe fibrosclerotic panniculopathy, more commonly known as cellulite. In the ongoing Phase 1 portion no serious or severe adverse events have been reported and the injection has been well tolerated. The most common adverse event has been mild to moderate pain at the injection site that was generally bilateral, lasted a few minutes and did not require treatment.

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"We are pleased with the emerging safety profile of HTI-501. Initial results of the Phase 1 study demonstrate that the enzyme has been well tolerated with no dose-limiting side effects," said Dr. Francisco Perez, President of the 8th World Congress of Cosmetic Dermatology and principal clinical investigator for the trial. "We look forward to advancing this program to the next phase as HTI-501 could offer an innovative approach to treating cellulite – a disease that currently has few viable treatment options."

The Phase 1 enzyme dose escalation portion of the trial continues and is evaluating a single injection of two different HTI-501 formulations into dimpled lesions of the skin. The Phase 2 portion of the trial will target multiple lesions with the optimal dose and formulation. Up to 48 and 76 subjects may be enrolled in the Phase 1 and Phase 2 portions of the trial, respectively.

About HTI-501

HTI-501, a recombinant human proteinase known as cathepsin-L (rHuCAT-L), is under development by Halozyme. HTI-501 is being investigated as a potential treatment for dermatologic and aesthetic conditions, as well as other indications. As a conditionally active biologic, HTI-501 is designed to allow local degradation of the collagenous fibrous components of the extracellular matrix at the injection site by tightly controlling the extent and duration of enzyme activity once injected into the body.

About Cellulite

Edematous fibrosclerotic panniculopathy, more commonly known as cellulite, is a condition found in 80-90 percent of post-adolescent women. It presents as a modification of skin topography evident by skin dimpling that occurs mainly on the pelvic region of women. In subcutaneous tissue, fibrous septae, made of types I and III collagen, connect the dermis to the deeper hypodermis. In cellulite, subcutaneous fat cells swell and push upwards while the septae act as an anchor to pull the epidermis downward to form the classic cellulite dimple lesion.

About Halozyme

Halozyme Therapeutics is a biopharmaceutical company dedicated to developing and commercializing innovative products that advance patient care. With a diversified portfolio of enzymes that target the extracellular matrix, the Company's research focuses primarily on a family of human enzymes, known as hyaluronidases, that increase the absorption and dispersion of biologics. Halozyme's pipeline addresses therapeutic areas, such as diabetes, oncology and dermatology that have significant unmet medical need. The Company markets HYLENEX® recombinant (hyaluronidase human injection) and has partnerships with Roche, Baxter, ViroPharma and Intrexon. Halozyme is headquartered in San Diego, CA. For more information on how we are innovating, please visit our corporate website at www.halozyme.com.

Safe Harbor Statement

In addition to historical information, the statements set forth above include forward-looking statements including without limitation our future development plans for HTI-501, anticipated study design and patient enrollment targets for the remainder of the Phase 1 study and future Phase 2 trial for HTI-501.  These forward-looking statements involve risk and uncertainties that could cause actual results to differ materially from those in the forward-looking statements. The forward-looking statements are also identified through use of the words "believe," "enable," "may," "will," "could," "intends," "estimate," "anticipate," "plan," "predict," "probable," "potential," "possible," "should," "continue," and other words of similar meaning. Actual results could differ materially from the expectations contained in forward-looking statements as a result of several factors, including clinical trial results, delays in development, possible adverse events associated with the use of the product candidate, regulatory approval requirements and competitive conditions. These and other risk factors that may result in differences are discussed in greater detail in the Company's reports on Forms 10-K, 10-Q, and other filings with the Securities and Exchange Commission.

Media/Investor Contact:
Anne Erickson
Executive Director
Halozyme Therapeutics
858-704-8264
[email protected]

SOURCE Halozyme Therapeutics, Inc.