Merck & Co. has adjusted its full-year profit outlook for 2025, lowering its adjusted earnings per share (EPS) guidance to a range of $8.82 to $8.97, down from a previous forecast of $8.88 to $9.03. This revision accounts for an estimated $200 million in additional costs due to tariffs, primarily affecting the company's operations between the U.S. and China. The new guidance also includes a one-time charge of 6 cents per share related to a licensing agreement with Hengrui Pharma. Despite the tariff impact, Merck's first-quarter performance in 2025 showed resilience, with the company reporting adjusted EPS of $2.22, surpassing the consensus estimate of $2.14. Total revenue for the quarter reached $15.53 billion, which was above the expected $15.31 billion. However, sales of the Gardasil vaccine declined by 41% year-over-year, attributed to lower demand in China. In contrast, Keytruda, Merck's top-selling cancer therapy, saw a 4% increase in sales to $7.21 billion, though this figure fell short of analyst expectations. Additionally, Merck reported 'increasingly meaningful' sales contributions from recently launched drugs Winrevair and Capvaxive.