Merck & Co. stock gains after guidance hike and Keytruda setback

Merck & Co. stock is trading near its 52-week high after the company raised its 2026 sales guidance, even as a rival lung cancer drug showed a survival benefit over Keytruda in new trial data.

Merck & Co., Inc. stock (ISIN US58933Y1055) is trading close to its recent 52-week high at 150.78 USD as of September 2, 2026 on the New York Stock Exchange, giving the U.S. pharmaceutical group a market capitalization of 369.73 billion USD according to ad-hoc-news data based on market portals.The latest quote snapshot shows the shares near a 52-week high of 156.92 USD, while investors digest a raised full-year sales outlook and fresh competitive data against cancer drug Keytruda.

Guidance raised on solid Q2 revenue

Merck & Co. reported second-quarter 2026 revenues of 16.61 billion USD, up 5% year over year on a reported basis and 4% excluding foreign exchange, with sales exceeding the consensus estimate of 16.33 billion USD according to Zacks.The earnings analysis highlights that pharmaceutical segment revenues reached 14.76 billion USD, rising 5% year over year, while the Animal Health segment contributed 1.78 billion USD, an 8% increase on a reported basis. In earnings terms, Merck posted an adjusted loss of 0.13 USD per share for the second quarter of 2026, which was narrower than the Zacks consensus expectation of a 0.26 USD loss per share and compared with adjusted earnings of 2.13 USD per share in the year-ago quarter.

The headline loss reflected a sizable business development impact: adjusted and reported earnings both included a charge of 2.31 USD per share linked to the acquisition of Terns Pharmaceuticals, completed during the quarter, while total reported loss came to 0.54 USD per share versus reported earnings of 1.76 USD per share a year earlier.The same report points out that operating expenses, excluding these business development charges, grew 7% in the quarter, underscoring ongoing investment behind Merck's pipeline and key franchises even as headline EPS was temporarily compressed by deal-related costs.

Higher 2026 sales guidance and lower EPS range

Against this backdrop, Merck & Co. raised its 2026 sales guidance, now expecting revenues between 66.3 billion USD and 67.3 billion USD compared with its prior range of 65.8 billion USD to 67.0 billion USD, implying year-over-year growth of 2% to 4% according to Zacks.The guidance breakdown further notes that Merck cut its adjusted earnings forecast to a range of 2.66 USD to 2.76 USD per share from a previous 5.04 USD to 5.16 USD, with the revised range including a one-time charge of 2.43 USD per share related to the Terns acquisition. For investors, the combination of higher revenue expectations and a temporarily depressed EPS range highlights the trade-off between near-term profitability and longer-term growth from strategic deals.

On the revenue side, the second-quarter performance shows Merck growing its top line by 5% year over year to 16.61 billion USD, while full-year guidance implies that the company aims to add roughly 0.5 billion USD at the midpoint versus its prior forecast.The Zacks commentary also notes that Merck shares have gained 18.2% since the last earnings report, outperforming the S&P 500 over that period, which underscores how the market has rewarded the company's willingness to accept near-term EPS dilution in exchange for pipeline-enhancing transactions.

Keytruda faces fresh competition in lung cancer

Beyond guidance, fresh clinical data has shifted the competitive narrative around Merck's leading immuno-oncology drug Keytruda. According to a market summary on Yahoo Finance dated September 3, 2026, Summit Therapeutics shares surged 14.5% after its partner Akeso reported that the Phase 3 HARMONi-2 trial met its prespecified interim overall survival endpoint, with ivonescimab monotherapy delivering a statistically significant survival advantage over Keytruda in PD-L1-positive advanced non-small cell lung cancer.The same market wrap notes that Merck shares slipped 0.9% on the news, illustrating how sensitive the stock remains to competitive signals around Keytruda, which is marketed by Merck and is widely recognized as one of the world's top-selling cancer drugs.

At the same time, Keytruda retains its status as a core component of Merck's portfolio, particularly in major oncology indications where its long-term survival data and breadth of approved uses remain central strengths. A newsletter from the Economic Times Pharma vertical dated September 4, 2026 highlights that pembrolizumab, marketed by Merck under the Keytruda brand, is among the top global oncology drugs, while Indian group Cipla has licensed United States rights to a biosimilar version from Qilu Pharmaceutical.The newsletter underlines that biosimilar competition to Keytruda is gradually emerging, which in turn makes Merck's guidance upgrades and business development activity more important for supporting long-term revenue growth even as pricing and competitive dynamics intensify.

Keytruda as a flagship product

Keytruda, Merck & Co.'s flagship programmed death receptor-1 (PD-1) blocking antibody, is approved for multiple cancer indications and has become one of the main drivers of the group's pharmaceutical revenues. In recent years, Keytruda has consistently ranked among the highest-grossing drugs globally, supported by expanding labels across lung cancer, melanoma, head and neck cancers and other tumor types, and it is cited in the Economic Times Pharma newsletter as the world's top oncology brand.The same newsletter mentions pembrolizumab under the Keytruda brand in the context of biosimilar rights, underscoring its central role in Merck's strategy and its importance for the company's future cash flows.

From an investor perspective, the latest ivonescimab data and the emergence of biosimilar development agreements around Keytruda are strategically significant because they highlight both the value of Merck's existing oncology franchise and the need for continued innovation and diversification. A positive takeaway in the current numbers is that total pharmaceutical segment revenues rose 5% year over year to 14.76 billion USD in the second quarter of 2026, while Animal Health revenues increased 8% to 1.78 billion USD, illustrating that Merck's earnings power is supported by multiple growth engines beyond a single product.The segment breakdown suggests that broader portfolio strength can help the group absorb competitive pressures in individual therapy areas while still supporting modest top-line growth.

Merck & Co. stock near recent highs

With Merck & Co. shares trading at 150.78 USD as of September 2, 2026 on the New York Stock Exchange, the stock remains close to its recent 52-week high of 156.92 USD, supported by an upgraded full-year sales guidance and a solid mid-single-digit revenue increase in the latest quarter.Ad-hoc-news data put the company's market capitalization at 369.73 billion USD as of the same date, placing Merck firmly among the largest constituents of the S&P 500 and underlining its significance for global healthcare investors. For retail investors, the key figures in focus are the 5% year-over-year revenue growth in the second quarter of 2026, the raised 2026 sales range of 66.3 billion USD to 67.3 billion USD and the narrowed adjusted loss of 0.13 USD per share compared with a consensus loss expectation of 0.26 USD per share.

Merck & Co. fact box

• Company: Merck & Co., Inc.
• ISIN: US58933Y1055
• Ticker: MRK
• Trading venue: NYSE
• Price (as of September 2, 2026, 10:49): 150.78 USD
• Market capitalization: 369.73 billion USD (as of September 2, 2026)
• Sector / Industry: Healthcare / Pharmaceuticals
• Index membership: S&P 500