New York, February 5, 2026, 14:03 EST — Market open for regular trading.
Shares of Merck & Co., Inc. climbed roughly 2% Thursday afternoon, hitting $120.72. The stock swung between $117.34 and $122.39, with volume near 12.8 million shares.
The move follows Merck’s forecast for 2026 sales and profits coming in below Wall Street’s estimates, citing a larger-than-expected impact from older drugs losing patent protection — the barrier that keeps generics at bay. BMO Capital’s Evan Seigerman said the quarter “builds a reasonable foundation for Merck heading into 2026,” but cautioned that the revenue outlook might dampen expectations. CEO Rob Davis highlighted “legacy products” going off patent as a key shortfall against forecasts. Reuters
This is crucial as Merck works to prove it can sustain growth amid mounting pressure on its established products and the impact of U.S. pricing changes. Investors are eyeing the pace of new launches and late-stage trial results to see if they can expand the narrative before Keytruda, the company’s top-selling drug, faces a patent expiry later this decade.
Merck also announced that Health Canada has approved ENFLONSIA (clesrovimab) to prevent RSV lower respiratory tract disease in newborns and infants during their first RSV season. “The approval of ENFLONSIA adds a new option for RSV prevention in infants,” said Matthew Thornhill, executive director for Merck Canada’s vaccines business unit, in a statement. Newswire
Merck posted fourth-quarter global sales of $16.4 billion and non-GAAP EPS of $2.04 in its latest update. The company expects 2026 full-year sales between $65.5 billion and $67.0 billion. It also forecast non-GAAP earnings per share for 2026 of $5.00 to $5.15, factoring in a one-time charge related to its Cidara deal. Additionally, Merck flagged an FDA filing for WINREVAIR, with the PDUFA date set for Sept. 21, 2026, marking the agency’s review deadline.
A Reuters Health Rounds report out this week highlighted early research indicating cancer immunotherapies might be more effective when administered earlier in the day. The study covered drugs including Merck’s Keytruda and Eli Lilly’s Tyvyt. Although preliminary, these findings add another layer to the ongoing exploration of Keytruda’s extensive development and label expansion plans.
Traders are focused less on the immediate quarter and more on how steep the headwinds Merck warned about will be—specifically, how fast legacy product sales might decline and if vaccines and new launches will fill the gap. Fresh insights into demand, particularly beyond the U.S., could quickly change the outlook.
The downside scenario is straightforward: generic competition hits harder and price erosion intensifies, while growth projects either stall or face regulatory hurdles. Even a calm market can shift quickly if investors start to believe the 2026 bridge is stretching out rather than closing in.
Merck’s first-quarter 2026 earnings call on April 30 is the next big date for investors, who will be looking for updated guidance on sales and profits. The company is also expected to give a clearer picture of how 2026 is shaping up.
