Investor Contact: Schond Greenway Halozyme Therapeutics 858-704-8352 ir@halozyme.com Media Contact: Denise Powell 510-703-9491 dpowell@brewlife.com HALOZYME REPORTS FIRST QUARTER 2014 FINANCIAL RESULTS Positive top-line

Halozyme Therapeutics

HALOZYME REPORTS FIRST QUARTER 2014 FINANCIAL RESULTS

Positive top-line data from studies with HTI-501 in cellulite and Hylenex with insulin pumps

SAN DIEGO, May 12, 2014 -- Halozyme Therapeutics, Inc. (NASDAQ: HALO) today reported financial results for the first quarter ended March 31, 2014. Financial highlights for the first quarter include revenues of $12.0 million and a net loss of $26.5 million, or $0.22 per share. This compares to revenues of $11.8 million and a net loss of $19.3 million, or $0.17 per share, for the first quarter of 2013. The increase in net loss reflects Halozyme's increased investment in clinical trials for its PEGPH20 and Hylenex proprietary programs.

"In the first quarter we saw advances in both our proprietary programs and in our partnered programs. We reported positive clinical trial results for the use of Hylenex in type 1 diabetes and for HTI-501 in cellulite. We also announced the European marketing authorization for MabThera SC, which is the third European approval for partnered programs that utilize our rHuPH20 technology. We ended the quarter in a strong financial position, supported by approximately $165 million in cash, cash equivalents and marketable securities," stated Dr. Helen Torley, President and Chief Executive Officer. "In early April, we temporarily halted dosing of PEGPH20 in Study 202 so the Data Monitoring Committee (DMC) could evaluate a possible imbalance in the rate of thromboembolic events between the drug arm and the control arm in the trial. We have since provided the DMC with requested information including an amended study protocol, and the DMC has informed us that they now support continued enrollment of patients and dosing of PEGPH20 in the trial with the proposed study modifications. We have provided information to the U.S. Food and Drug Administration (FDA) so they can conduct their assessment of our request for the clinical hold to be lifted so we may continue enrollment of patients and dosing of PEGPH20 in the Phase 2 trial."

First Quarter 2014 Highlights

First Quarter 2014 Financial Highlights

Financial Outlook for 2014

Webcast and Conference Call

Halozyme will webcast its quarterly update conference call today, May 12, 2014 at 4:30 p.m. EDT/1:30 p.m. PDT. During the call, management will discuss the financial results for the first quarter of 2014 and provide a business update. To listen to the live webcast please visit the "Investors" section of Halozyme's corporate website at www.halozyme.com. A webcast replay will be available shortly after the call at the same address. For those without access to the Internet, the live call may be accessed by phone by calling (866) 710-0179 (domestic callers) or (334) 323-7224 (international callers) using passcode 769890. A telephone replay will be available shortly after the call by dialing (877) 919-4059 (domestic callers) or (334) 323-0140 (international callers) using replay ID number 74917420.

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, which increase the dispersion and absorption of biologics, drugs and fluids. Halozyme's pipeline addresses therapeutic areas, including oncology, diabetes and dermatology that have significant unmet medical need today. The Company markets Hylenex recombinant (hyaluronidase human injection) and has partnerships with Roche, Pfizer and Baxter. Halozyme is headquartered in San Diego. 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, statements concerning the possibility that FDA may lift the clinical hold on patient enrollment and dosing of PEGPH20, the Company's planned presentation of data from CONSISTENT 1 at the 74th Scientific Sessions of the American Diabetes Association, the Company's expected net cash burn for 2014 and Company's other future expectations and plans for its business, financial results and the development and commercialization of product candidates and the potential benefits and attributes of such product candidates) 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 typically, but not always, 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 requirements, delays in development and regulatory review, unexpected adverse events, unexpected expenditures and costs, unexpected fluctuations or changes in revenues from collaborators and competitive conditions. These and other factors that may result in differences are discussed in greater detail in the Company's Annual Report on Form 10-K filed with the Securities and Exchange Commission on February 28, 2014.

Halozyme Therapeutics, Inc.

Condensed Consolidated Statements of Operations

(in thousands, except per share data)

Halozyme Therapeutics, Inc.

Condensed Consolidated Balance Sheets