Merck & Co. (NYSE: MRK) shares climbed 3.84% to $146.34 on October 29, gaining $5.41 during the trading session, after the pharmaceutical company reported third-quarter 2026 revenue of $18.1 billion, a 5% increase compared with the prior year. The stock added a further 0.74% to $147.42 in after-hours trading, as the financial results highlighted continued product demand and pipeline progress.

Third-Quarter Revenue Reaches $18.1 Billion

Merck generated $18.085 billion in worldwide sales during the third quarter, up from $17.276 billion in the same period of 2025. Foreign exchange movements reduced reported growth, leaving revenue up 4% when excluding currency effects. Purchasing patterns contributed approximately $550 million to pharmaceutical sales growth during the quarter.

The pharmaceutical division recorded $16.268 billion in sales, a 4% increase from the previous year. Growth came primarily from KEYTRUDA, WINREVAIR, GARDASIL, WELIREG and ENFLONSIA, along with the addition of OHTUVAYRE sales. Declining sales of JANUVIA, JANUMET, BRIDION and LAGEVRIO partly offset these gains.

Merck reported GAAP earnings per share of $2.04, down 12% from $2.32 a year earlier. Adjusted non-GAAP earnings per share fell 3% to $2.49 from $2.58 in the corresponding period. Both earnings measures included a one-time charge of $0.12 per share associated with a global licensing agreement with SciBrunch Therapeutics.

KEYTRUDA and WINREVAIR Drive Product Sales Growth

KEYTRUDA and KEYTRUDA QLEX generated combined sales of $8.601 billion, marking a 6% increase year over year. That total amounted to more than half of the pharmaceutical division's quarterly sales, a gauge of the franchise's weight in Merck's overall results. Demand rose across earlier-stage indications, including triple-negative breast cancer, cervical cancer, head and neck cancer and bladder cancer. Metastatic indications, including urothelial cancer, also contributed to stronger global demand, while KEYTRUDA QLEX generated $830 million.

WINREVAIR posted sales of $694 million, up 93% from $360 million in the third quarter of 2025. Higher demand and favorable purchasing patterns supported growth in the United States, while launches in international markets expanded the product's commercial performance, with Europe and Japan among the contributing regions.

GARDASIL and GARDASIL 9 sales rose 14% to $1.995 billion, supported by stronger US sales and favorable public-sector purchasing patterns. Sales of PROQUAD, M-M-R II and VARIVAX increased 7% to $730 million, reflecting higher demand in selected European markets. In contrast, JANUVIA and JANUMET sales dropped 39% to $380 million following generic competition after the drugs lost US market exclusivity. The contrast illustrated the portfolio-renewal cycle common across the pharmaceutical industry, in which newer brands take on greater revenue weight as established drugs lose exclusivity to generics.

Pipeline Advances and Raised Full-Year 2026 Outlook

Merck presented pivotal Phase 3 oncology data at the 2026 European Society for Medical Oncology (ESMO) Congress, highlighting progress across its development pipeline. The company reported results from the TroFuse-005 trial evaluating sacituzumab tirumotecan in certain patients with advanced or recurrent endometrial cancer. The US Food and Drug Administration accepted the related biologics license application for priority review. Priority review places the application on an expedited regulatory path, making it a near-term milestone within the pipeline.

Merck also presented Phase 3 findings from INTerpath-001, which evaluated intismeran autogene combined with KEYTRUDA as adjuvant treatment for resected stage IIB-IV melanoma. The program is being conducted in collaboration with Moderna, advancing the company's investigation of therapeutic cancer vaccines. In addition, Merck reported positive Phase 2b results for tulisokibart in moderate-to-severe hidradenitis suppurativa and presented one-year results from the BRUNELLO trial of remigromig in adults with diabetic macular edema.

Alongside its clinical updates, Merck raised the midpoint of its full-year 2026 worldwide sales outlook and narrowed its forecast to $66.8 billion–$67.3 billion. The company also narrowed its expected non-GAAP earnings-per-share range to $2.77–$2.82, a range that includes the $0.12 charge related to the SciBrunch agreement. The updated outlook reflects continued commercial contributions from established medicines and newer products, alongside developments across the broader pharmaceutical pipeline.

Merck's third-quarter results combined stronger revenue and substantial WINREVAIR growth with a year-over-year decline in reported earnings. The company's raised annual sales outlook and advancing clinical programs framed MRK's share-price gains on October 29.