December 26, 2013

VIA EDGAR

David A. Ramsay

(858) 704-8260 

dramsay@halozyme.com

Mr. Jim B. Rosenberg

Senior Assistant Chief Accountant

Securities and Exchange Commission

Division of Corporation Finance

100 F Street, N.E.

Washington, DC 20549

Re:      Halozyme Therapeutics, Inc.

Form 10-K for the Fiscal Year Ended December 31, 2012

Form 10-Q for the Quarterly Period Ended September 30, 2013

File No. 001-32335

Dear Mr. Rosenberg:

We are writing in response to your letter dated December 20, 2013 (the “Comment Letter”) setting forth certain comments of the Staff (the “Staff”) of the Securities and Exchange Commission relating to the above referenced filings. Confirming the telephone conference on December 20, 2013 between Mr. Mark Brunhofer of the Staff and Douglas Rein of DLA Piper LLP (US), our outside counsel, we understand that the Staff has provided an extension of an additional ten business days for the Company to respond to the Comment Letter. As such, the Company intends to submit its response to the Comment Letter on or before January 21, 2014. Thank you for your consideration.

Very truly yours,

/s/ David A. Ramsay            

David A. Ramsay

Vice President and Chief Financial Officer

cc: Jean Liu, Halozyme Therapeutics, Inc.

Douglas Rein, DLA Piper LLP (US)

Halozyme Therapeutics, Inc., 11388 Sorrento Valley Road, San Diego, California 92121 Office 858.794.8889 Fax 858.704.8311 www.halozyme.com