Exhibit 99.1 Press Release Regeneron Reports Second Quarter 2025 Financial and Operating Results Tarrytown, New York (August 1, 2025) -- Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) today announced financial results for the second quarter of 2025 and provided a business update. "Regeneron had a strong quarter, marked by significant growth in U.S. sales of EYLEA HD and global sales of Dupixent and Libtayo along with multiple regulatory approvals," said Leonard S. Schleifer, M.D., Ph.D., Board co-Chair, Pre ...