HALO: Other company developments

Item 8.01 Other Events On September 16, 2026, Halozyme Therapeutics, Inc. (the “Company”) issued a press release announcing that it proposes to offer, subject to market conditions and other factors, $1.05 billion aggregate principal amount of convertible senior notes due 2033 (the “Convertible Notes”). The Company also expects to grant a 13-day option to the initial purchasers to purchase up to an additional $150 million aggregate principal amount of the Convertible Notes. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated into this Item 8.01 by reference. Item 9.01 Financial Statements and Exhibits. (d) Exhibits Exhibit No. Description 99.1 Press release dated September 16, 2026 104 Cover Page Interactive Data File (formatted as inline XBRL and contained in Exhibit 101) *Certain schedules omitted pursuant to Item 601(a)(5) of Regulation S-K. Halozyme agrees to furnish supplementally a copy of any omitted schedule to the SEC upon request. SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. Halozyme Therapeutics, Inc. (Registrant) Dated: September 16, 2026 By: /s/ Darren Snellgrove Darren Snellgrove Executive Vice President, Chief Financial Officer