Merck Shares Climb Following EU Approval for Keytruda and Top Trading Volume

Market Overview

On April 2, 2026, Merck (MRK) experienced a slight uptick in its share price, rising by 0.02%. Although the price change was minimal, Merck led the market in trading activity with a total volume of $0.77 billion—the highest among all listed companies that day. This surge in trading volume points to heightened investor engagement and possibly increased momentum within the healthcare sector. The restrained price movement likely reflects a mix of optimism about Merck’s drug development progress and investor caution as broader market trends evolve.

Major Catalysts

Merck recently achieved a significant regulatory advancement with the European Commission’s approval of Keytruda, in combination with paclitaxel, for certain adults with platinum-resistant ovarian cancer. This decision follows a favorable opinion from the European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP) in February 2026. The approval allows Merck to offer Keytruda to adult patients with PD-L1–positive tumors who have already undergone one or two systemic treatments, making Keytruda the first PD-1 inhibitor-based therapy for this patient group in the European Union. This milestone further strengthens Merck’s leadership in the field of immuno-oncology.

The European Commission’s decision was based on compelling results from the Phase 3 KEYNOTE-B96 (ENGOT-ov65) clinical trial. In this study, patients receiving Keytruda plus paclitaxel—with or without bevacizumab—experienced significant improvements in both progression-free survival (PFS) and overall survival (OS) compared to those on placebo. Specifically, the combination therapy reduced the risk of disease progression or death by 28% (HR=0.72; p=0.0014), with median PFS extending to 8.3 months versus 7.2 months. For overall survival, the risk of death was lowered by 24% (HR=0.76; p=0.0053), with median OS reaching 18.2 months compared to 14.0 months. These findings highlight the potential of Keytruda-based regimens to improve outcomes for patients facing difficult-to-treat ovarian cancers.

Merck noted that this regulatory approval will shape its commercialization plans across the European Union, as well as in Iceland, Liechtenstein, and Norway. However, the timing of Keytruda’s launch in each country will depend on national reimbursement processes and other local considerations. While gaining approval is a major step, Merck must still navigate complex reimbursement systems throughout the region. The expanded indication gives Merck a stronger position in an area with significant unmet needs, especially as ovarian cancer rates and cases resistant to platinum-based therapies continue to rise worldwide.

This development also fits into Merck’s broader strategy to advance treatments for women’s cancers, including breast and gynecologic malignancies. The company is conducting over 20 clinical trials involving nearly 20,000 participants globally, aiming to discover new combinations and earlier interventions for these diseases. The positive results for Keytruda in ovarian cancer underscore Merck’s dedication to using its immuno-oncology expertise to address critical gaps in care. This progress is particularly important as Merck prepares for future patent expirations and the competitive pressures they may bring to Keytruda’s market share.

Additionally, the European approval adds to a series of recent successes for Merck in oncology. In February 2026, the U.S. Food and Drug Administration (FDA) also approved Keytruda with paclitaxel, with or without bevacizumab, for the same indication in the United States. This alignment of regulatory decisions across major markets enhances Merck’s ability to expand access to Keytruda and potentially boost its oncology revenues. Although Merck’s stock price showed little immediate reaction to the news, the long-term significance of this approval—given Keytruda’s central role in Merck’s portfolio—could attract greater investor interest in the near future.