Merck & Co.'s stock price has surged 85.5% over the past 12 months, with its current price-to-sales (P/S) ratio reaching 5.7x, close to its decade-high of 5.9x. Analysis suggests that its core oncology product, the KEYTRUDA series, generated $8.4 billion in sales in Q2 2026, accounting for approximately half of the company's total revenue of $16.6 billion. However, the growth rate of this product line has slowed from 8% in Q1 to 4% in Q2. Management anticipates that KEYTRUDA's growth will stabilize, and in Q3 2026, it will face the impact of a high base from elevated wholesaler purchases in the same period of 2025. Despite Merck & Co. boasting over 20 new products and an R&D pipeline valued at over $70 billion, these new products have not yet fully supported its valuation.