Merck stock trades steadily as Keytruda and vaccine revenue underpin earnings

Merck stock reflects a business increasingly driven by cancer drug Keytruda and vaccines, with recent quarterly figures showing higher revenue and earnings despite looming patent expiries.

Merck & Co., Inc. (ISIN US58933Y1055) remains one of the largest US health care groups listed on the New York Stock Exchange, and Merck stock continues to be supported by rising oncology and vaccine revenue alongside solid earnings growth in recent reporting periods. According to the companys latest annual and quarterly disclosures for fiscal 2024 and early 2025, Merck reported multi-billion-dollar sales for its cancer therapy Keytruda and its vaccines portfolio, helping the group deliver higher total revenue and adjusted earnings per share compared with the prior year.

Revenue up double digits year on year

In its most recent full-year report for fiscal 2024, Merck stated that total revenue reached a level clearly above the prior-year figure, driven largely by oncology medicines and vaccines. The company reported that revenue excluding certain one-off items increased at a double-digit percentage rate versus fiscal 2023, with oncology revenue alone rising markedly year on year thanks to the performance of its immunotherapy Keytruda. In addition, Merck indicated that its vaccines segment, including the human papillomavirus vaccine Gardasil and pediatric vaccines, achieved higher sales compared with the prior year as demand recovered and expanded in several markets.

Keytruda remained Mercks largest single product by revenue in fiscal 2024. The group disclosed that Keytruda sales rose firmly versus 2023, reflecting greater use in lung cancer and other tumor types and continued geographic expansion. Vaccine revenue also grew at a healthy pace, helping Merck offset declines in certain mature primary care franchises and the impact of patent expiries in other therapeutic areas. For investors, the quantified comparison is important: Merck reported a clear year-on-year increase in oncology-related revenue and overall revenue, underlining the central role of these growth drivers in the business mix.

Margin and EPS trends support Merck stock

Beyond top line growth, Merck highlighted in its recent results that adjusted earnings per share improved compared with the prior year, supported by revenue growth and cost discipline. The company reported that operating income and margin expanded, with adjusted EPS rising versus fiscal 2023. In quarterly updates during 2024 and early 2025, Merck indicated that adjusted EPS for the period came in above the comparable prior-year quarter, reflecting a combination of higher oncology and vaccines revenue and an efficient expense base.

Merck also emphasized cash generation and balance sheet strength in its investor reports. The group disclosed solid operating cash flow for fiscal 2024 and reiterated its commitment to returning cash to shareholders through dividends and share repurchases, while continuing to invest in research and development and targeted acquisitions. For equity holders following Merck stock, this combination of revenue growth, margin expansion, and cash generation gives the company room to manage upcoming patent cliffs and fund clinical development, even as competitive pressures increase in several therapy areas.

Keytruda drives oncology leadership

Oncology is the central pillar of Mercks growth story, and Keytruda sits at the core of that pillar. The drug has secured approvals across multiple cancer types, including non-small cell lung cancer, melanoma, and several other solid tumors, increasingly as part of first-line treatment combinations. This breadth of use has translated into rising volume and value, with Keytruda revenue now accounting for a substantial share of Mercks overall pharmaceutical sales. In recent years, Merck has repeatedly reported double-digit percentage growth in Keytruda sales compared with the prior year, reinforcing the products status as a cornerstone of the companys earnings power.

Merck continues to invest heavily in Keytruda-related research, pursuing new indications, earlier lines of therapy, and combination regimens with other cancer agents. The company has numerous ongoing phase III trials that aim to extend Keytruda into additional tumor types and patient groups. Success in these studies would not only support future revenue but also underpin the longevity of Mercks oncology franchise beyond forthcoming patent expiries. For Merck stock, the trajectory of Keytruda data and approvals remains a crucial factor in investors long-term expectations for earnings and cash flow.

At the same time, Merck is working on next-generation oncology assets, including antibody-drug conjugates and other immunotherapies, to diversify its cancer portfolio and reduce dependence on a single product. While Keytruda currently dominates the oncology revenue mix, management has signaled a strategic emphasis on building a broader suite of cancer therapies through internal development and business development deals. This strategy is intended to support sustainable growth in oncology and mitigate concentration risk over time.

Vaccines segment adds resilience

Alongside oncology, vaccines provide Merck with a second major revenue stream that adds resilience to the overall business. The companys vaccine portfolio includes Gardasil for human papillomavirus, pediatric vaccines, and other prophylactic products that help prevent infectious diseases. Merck has reported year-on-year increases in vaccine revenue in recent reporting periods, reflecting higher demand for HPV vaccination and expanding immunization coverage in several markets. These vaccines not only generate substantial sales but also align the company with global public health priorities.

Gardasil in particular has posted robust growth, benefiting from increased awareness of HPV-related cancers and wider adoption in national vaccination programs. Merck has emphasized in its investor materials that higher Gardasil volume has contributed meaningfully to the vaccines segments revenue increase compared with the prior year. For Merck stock, the presence of a growing vaccines franchise complements oncology by providing a somewhat different demand profile and revenue pattern, potentially less sensitive to the timing of clinical trial readouts than the pipeline-based oncology business.

Merck is also engaged in research on new vaccines and improvements to existing ones, aiming to maintain its competitive position in a field that includes major peers. While competition is intense, Mercks combination of established brands and ongoing development helps sustain the vaccines business as a key revenue contributor and risk diversifier within its broader pharmaceutical portfolio.

Patent expiries and pipeline balance

A central question for any large pharmaceutical group is how it manages the transition from current blockbuster products to new therapies as patents expire. Merck faces upcoming loss of exclusivity for Keytruda and other products in the 2030s, and the company has been clear that pipeline development and business development deals are critical to its long-term strategy. In its investor presentations, Merck has highlighted a deep pipeline of oncology, vaccines, and specialty products, with multiple late-stage and registrational programs.

Management has pointed out that the companys research and development spending, while substantial, is aimed at creating new growth engines that can enter the portfolio before and after key patent cliffs. The focus is not only on incremental improvements but also on therapies that could become future pillars comparable to todays Keytruda. For holders of Merck stock, the balance between near-term earnings delivered by existing blockbusters and long-term prospects tied to pipeline outcomes is a central aspect of the investment case.

Merck has also used targeted acquisitions and licensing deals to supplement its internal pipeline, expanding into areas such as cardiometabolic disease, infectious disease, and additional oncology segments. These transactions aim to bring in promising assets that can be developed within Mercks global infrastructure and commercial network. Over time, successful integration of acquired or licensed products can help smooth the earnings profile as older products move closer to patent expiry.

Dividend and capital allocation priorities

Merck has a long history of paying dividends, and its capital allocation strategy includes returning cash to shareholders while funding innovation. In recent years, the company has maintained a regular quarterly dividend, and dividend payments for fiscal periods such as 2023 and 2024 have represented a meaningful portion of cash outflows. Merck has also repurchased shares, although buyback activity may vary depending on market conditions, valuation, and other capital needs.

At the same time, Merck invests heavily in research and development and in capital expenditure to support manufacturing and distribution infrastructure. Management has emphasized that R&D remains a top priority, given the need to replenish and expand the portfolio as major products face future competition. The companys strong operating cash flow and balance sheet give it flexibility to pursue both shareholder returns and growth investments, which is an important consideration for Merck stock in the context of long-term total return potential.

Merck has also addressed debt levels and credit ratings in its communications with investors. The group aims to maintain a solid investment-grade credit profile, which supports access to capital markets on favorable terms. Prudent leverage management helps ensure that Merck can fund acquisitions and pipeline investments without compromising financial stability.

Keytruda and Gardasil highlight Mercks product strength

Merck & Co.s product portfolio is broad, but two names often stand out: Keytruda in oncology and Gardasil in vaccines. Keytruda is an immune checkpoint inhibitor that has become standard of care in multiple cancer types, particularly non-small cell lung cancer, and has fundamentally changed expectations for survival in certain patient groups. Its success has turned it into a multi-billion-dollar product and the main engine of Mercks current revenue growth. Merck continues to support Keytruda with substantial clinical development to extend its reach and solidify its position in evolving treatment guidelines.

Gardasil, Mercks HPV vaccine, plays an important role in preventing infections that can lead to cervical and other cancers. The product is included in many immunization programs worldwide and has seen increasing uptake as awareness of HPV-related disease has grown. Gardasil generates significant revenue and anchors Mercks vaccines business, which in turn supports the companys diversification beyond oncology. Other vaccines in Mercks portfolio, along with pediatric and adult immunization products, complement Gardasil and help maintain scale in vaccine manufacturing and distribution.

Together, Keytruda and Gardasil illustrate how Merck blends high-impact therapeutic innovation with public health-oriented preventive products. For Merck stock, the success and resilience of these two franchises provide a foundation for earnings and cash flow, even as the company works to build future pillars in other therapeutic areas.

Merck stock and market positioning

Merck & Co. is a major constituent of US large-cap health care indices, and Merck stock is widely held by both institutional and retail investors. The shares are traded on the New York Stock Exchange under the ticker MRK and form part of the broader US pharmaceuticals and biotechnology sector. Over recent years, Mercks share price performance has reflected a mix of company-specific developments, such as Keytrudas growth and pipeline updates, and sector-wide factors, including regulatory changes and macroeconomic trends.

Market participants often compare Merck with other large global pharmaceutical companies when assessing valuation metrics such as price-to-earnings ratios, dividend yields, and growth expectations. Mercks strong oncology and vaccines franchises, combined with its pipeline, dividend policy, and financial profile, shape the way its stock is perceived relative to peers. For investors, the key questions include how durable Keytrudas earnings contribution will be, how quickly new products can ramp up, and how Merck will navigate the competitive landscape in vaccines and specialty care.

In addition, broader health care policy developments, including drug pricing discussions and reimbursement frameworks, can influence sentiment toward Merck stock. The companys ability to adapt to changing policy environments while continuing to deliver clinical and economic value through its medicines and vaccines is likely to remain an important determinant of longer-term share performance.

Merck & Co. key data

• Company: Merck & Co., Inc.
• ISIN: US58933Y1055
• Ticker: NYSE: MRK
• Trading venue: NYSE
• Sector / Industry: Health Care / Pharmaceuticals
• Index membership: S&P 500