Merck Stock Rises on Keytruda EU Approval and Leads in Trading Volume

Market Snapshot

On April 2, 2026, Merck (MRK) saw its stock rise by 0.02%, a modest but notable movement in a market where trading volumes and price reactions are often influenced by broader economic trends and sector-specific news. The company’s shares traded with a total volume of $0.77 billion, marking the highest trading volume for the day among all listed stocks. Despite the limited price increase, the high trading volume suggests investor interest and potentially increased activity in the healthcare sector. The muted price movement may reflect a balance between positive developments in Merck’s therapeutic pipeline and cautious investor sentiment ahead of broader market shifts.

Key Drivers

The European Commission’s recent approval of Merck’s Keytruda in combination with paclitaxel for certain patients with platinum-resistant ovarian cancer marks a significant regulatory milestone for the company. This approval, which follows a positive recommendation from the European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP) in February 2026, enables Merck to expand the availability of Keytruda in a high-priority oncology indication. The therapy is specifically approved for adult patients with PD-L1–positive tumors who have received one or two prior systemic treatment regimens. This decision not only reinforces Merck’s leadership in immuno-oncology but also positions Keytruda as the first PD-1 inhibitor-based treatment for this specific patient population in the EU.

The approval is grounded in robust clinical evidence from the Phase 3 KEYNOTE-B96 trial, also known as ENGOT-ov65. In this trial, Keytruda plus paclitaxel, with or without bevacizumab, demonstrated a statistically significant and clinically meaningful improvement in both progression-free survival (PFS) and overall survival (OS) compared to the placebo regimen. The trial showed a 28% reduction in the risk of disease progression or death (HR=0.72; p=0.0014), with a median PFS of 8.3 months versus 7.2 months. For OS, Keytruda-based therapy reduced the risk of death by 24% (HR=0.76; p=0.0053), with a median OS of 18.2 months versus 14.0 months. These results underscore the therapy’s potential to improve patient outcomes in a challenging subset of ovarian cancer cases and are likely to bolster confidence in the drug’s long-term value.

Merck emphasized that the European Commission’s decision will impact its plans for commercialization across the EU, Iceland, Liechtenstein, and Norway. The company noted that national reimbursement procedures and other country-specific factors will influence the timing of Keytruda’s launch for this indication in each nation. While the approval is a regulatory win, Merck faces the challenge of navigating the complex reimbursement landscape across multiple jurisdictions. Nevertheless, the expanded label provides a strategic foothold in a disease area with significant unmet medical needs and limited treatment options. This is especially relevant given the increasing incidence of ovarian cancer globally and the growing prevalence of platinum-resistant cases.

The approval also aligns with Merck’s broader research strategy in women’s cancers, which includes advancing therapies for breast and gynecologic malignancies. With more than 20 clinical trials involving nearly 20,000 patients worldwide, Merck is actively exploring novel combinations and earlier-stage interventions in these cancers. The success of Keytruda in ovarian cancer reinforces the company’s commitment to leveraging its immuno-oncology platform to address critical gaps in treatment. The news is particularly timely as Merck continues to prepare for potential patent expirations and the associated market pressures on Keytruda in the coming years.

Finally, the European approval adds to a series of positive developments for Merck in the oncology space. In February 2026, the U.S. Food and Drug Administration (FDA) also approved Keytruda in combination with paclitaxel, with or without bevacizumab, for the same indication in the U.S. The global regulatory harmonization of this indication enhances Merck’s ability to scale the therapy’s reach and potentially increase its revenue contribution from oncology. While the stock price did not react strongly to the news on April 2, the long-term implications of this approval—particularly in light of Keytruda’s strategic importance to Merck—could drive more pronounced investor interest in the weeks and months ahead.