Halozyme Therapeutics, Inc. Completes Enrollment in Chemophase Phase I/IIa Clinical Trial for Superficial Bladder Cancer

SAN DIEGO, Sept. 25 /PRNewswire-FirstCall/ -- Halozyme Therapeutics, Inc. , a biopharmaceutical company developing and commercializing products based on the extracellular matrix, today announced that enrollment is complete in its Chemophase(R) Phase I/IIa clinical trial for the treatment of superficial bladder cancer. The Company began dosing patients in this trial in April of last year, following the successful completion of the initial Phase I trial of a single-administration of Chemophase and mitomycin. Patient enrollment in this Phase I/IIa trial required stepwise enrollment by escalating dose cohort, with a pause for safety evaluation required after the last patient in the previous cohort had completed at least the first four of the six weekly study drug instillations. Chemophase is a novel recombinant investigational therapeutic being developed to enhance the delivery of chemotherapy.

The Chemophase Phase I/IIa clinical trial is a multi-center, open label, nonrandomized study to evaluate multiple intravesical (into the bladder) administrations of Chemophase along with the widely used anticancer drug mitomycin in patients with superficial bladder cancer. This dose-finding Phase I/IIa study enrolled 27 patients with superficial bladder cancer. The objectives of the study included determining the maximum tolerated dose (MTD) and dose-limiting toxicities, if any, of escalating doses of mitomycin and then Chemophase in combination with mitomycin administered as weekly intravesical instillations for six weeks, consistent with the usual standard of care; establishing the optimal dose of Chemophase with mitomycin to be recommended for future studies; and observing patients for any preliminary evidence of anti-tumor activity of this combination therapy. The trial is ongoing, as the most recently enrolled patients complete their initial six weekly treatments, all patients are monitored according to standard of care for tumor recurrence, and the patients enrolled at the MTD cohort continue maintenance dosing until the end of Year 2 of the study.

“We are pleased to have reached another important milestone in the development of Chemophase, which is proceeding along our expected timeline. We hope to announce interim data from this ongoing trial during the first half of next year,” said Jonathan Lim, MD, Halozyme’s President and CEO.

In the Chemophase Phase I trial, pharmacokinetic data were obtained from the plasma of five bladder cancer patients dosed intravesically with 20,000 units of Chemophase along with 40 mg of mitomycin. The observed plasma levels of mitomycin were less than 1/40th of the levels reported to be predictive of suppression of white blood cell production. The study was conducted at BCG Oncology in Phoenix, Arizona under the supervision of Donald L. Lamm, MD, the principal investigator.

The American Cancer Society estimates that there are approximately 67,000 new cases of bladder cancer diagnosed in the United States annually. At any given time, it is estimated that there are more than 500,000 bladder cancer patients in the U.S. According to Botteman et al., (PharmacoEconomics 2003), bladder cancer is the fifth most expensive cancer to treat. The initial treatment of this cancer is surgical removal of the tumor. Because of the high frequency of early recurrences of the tumor, patients are usually prescribed additional therapy to prevent or delay such recurrences. This additional therapy generally consists of immunotherapy or chemotherapy drugs instilled directly into the bladder.

About Halozyme Therapeutics, Inc.

Halozyme is a biopharmaceutical company developing and commercializing products based on the extracellular matrix for the drug delivery, oncology, and dermatology 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. Its first partnership is with Roche to apply Enhanze Technology to Roche’s biological therapeutic compounds for up to 13 targets. 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. HYLENEX is partnered with Baxter Healthcare Corporation. The Company also has a number of different enzymes in its portfolio that are targeting significant areas of unmet need.

Safe Harbor Statement

In addition to historical information, the statements set forth above include forward-looking statements (including, without limitation, statements concerning the development of Chemophase and the release of interim data related to current clinical trials) that 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 regulatory approval requirements and competitive conditions. These and other 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.

Halozyme Contact Investor Relations Contact David A. Ramsay Don Markley Chief Financial Officer Lippert/Heilshorn & Associates (858) 794-8881 (310) 691-7100 dramsay@halozyme.comdmarkley@lhai.com Media Contacts Karen Sparks / Joleen Schultz Mentus (858) 455-5500, x275/x215 karen@mentus.comjschultz@mentus.com

Halozyme Therapeutics, Inc.

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. 275, karen@mentus.com, or Joleen Schultz Mentus,+1-858-455-5500 ext. 215, jschultz@mentus.com, both for HalozymeTherapeutics, Inc.

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