Will Merck's Keytruda Continue to Drive Growth Amid Looming LOE?

Core Insights - Merck (MRK) has over six blockbuster drugs, with Keytruda being the primary revenue driver, accounting for approximately 50% of pharmaceutical sales [1][9] - Keytruda's sales are increasing due to its rapid adoption in early-stage non-small cell lung cancer (NSCLC) and continued strong performance in metastatic indications [2] - There are concerns regarding Merck's heavy reliance on Keytruda, especially with the impending loss of exclusivity in 2028, prompting the need for diversification [3] Sales and Growth - Keytruda generated sales of $7.21 billion in Q1 2025, reflecting a 6% year-over-year growth, with an estimated compound annual growth rate (CAGR) of 5.4% over the next three years [7][9] - Merck is exploring innovative strategies to sustain Keytruda's growth, including combinations with LAG3 and CTLA-4 inhibitors, and a partnership with Moderna for a personalized mRNA therapeutic cancer vaccine [5][9] Competitive Landscape - Competitive pressure for Keytruda may increase, particularly with Summit Therapeutics' ivonescimab showing promising results in a phase III study, which could challenge Keytruda's market position [4] Future Strategies - Merck is developing a subcutaneous formulation of Keytruda to potentially extend its patent life, with an FDA decision expected in September [6] - The company is also banking on the recently launched pulmonary arterial hypertension (PAH) drug Winrevair to support revenue after Keytruda's exclusivity ends [7] Valuation and Market Performance - Merck's shares have decreased by 19.6% this year, contrasting with a 0.3% increase in the industry [8] - From a valuation perspective, Merck's price/earnings ratio stands at 8.55, which is lower than the industry average of 15.12 and its own 5-year mean of 12.89 [10]