Exhibit 99.1 HALOZYME RAISES 2025 FINANCIAL GUIDANCE RANGES AND REPORTS STRONG FIRST QUARTER 2025 RESULTS Announcing New $250M Share Repurchase Total Revenue Increased 35$265 million and Royalty Revenue Increased 39% YOY to $168 million Net Income Increased 54$118 million; Adjusted EBITDA Increased 40% YOY to $162 million; GAAP Diluted EPS Increased 55$0.93; non-GAAP Diluted EPS Increased 41% YOY to $1.11 1 Raising 2025 Financial Guidance Ranges for Total Revenue to$1,200 - $1,28 ...