Before the US stock market opened on Friday, July 31st, the global tumor immunology field received major news. The American pharmaceutical giant Merck (NYSE: MRK) announced that its core product KEYTRUDA (pembrolizumab) achieved overwhelming survival improvement data in a large Phase III clinical trial targeting late-stage non-small cell lung cancer. Following the announcement, Merck's stock surged over 8% in pre-market trading, leading to a collective rise in the biopharmaceutical sector and a corresponding strengthening of the S&P 500 index futures.
KEYTRUDA New Data: Overall Survival Extended by Over 12 Months
According to the detailed data released by Merck, KEYTRUDA extended the median overall survival by over 12 months compared to standard therapy in a trial treating late-stage non-small cell lung cancer in combination with chemotherapy, demonstrating high statistical significance and clinical relevance. Key data points include:
The median overall survival (OS) reached 34.5 months, compared to 21.8 months in the control group, representing an extension of nearly 60%;
Progression-Free Survival (PFS) also showed significant improvement, with a Hazard Ratio (HR) of 0.68;
Objective Response Rate (ORR) increased to 62%, higher than the 48% in the control group;
Safety profile was consistent with previous KEYTRUDA trials, with no increase in the incidence of Grade 3 or higher adverse events.
This is one of the largest survival advantage data points for KEYTRUDA in the first-line treatment of lung cancer. Although the drug already has approved indications for various cancers, the release of this data, given that lung cancer is the most prevalent cancer globally, further solidifies Merck's leading position in the tumor immunology sector.
Fundamentals Reaffirmed, Yet Market Concerns Remain
KEYTRUDA has been a pillar of Merck's performance, generating over $31 billion in global sales in 2025, accounting for over 40% of the company's total revenue. However, in recent years, market concerns regarding the future growth prospects of KEYTRUDA arose due to the emergence of biosimilars and the approaching patent expiration. The announcement of this new data not only promises to support the expansion of the drug's coverage in existing indications but may also pave the way for new indications.
It is worth noting that Merck has also been expanding in other areas recently, such as acquiring a biotech company specializing in antibody-drug conjugates (ADC) to enrich its oncology pipeline. The timing of this data release is opportune, adding value to the company's image before investors.
Sector Linkage: Capital Quietly Flows Back to Pharmaceuticals
Driven by Merck's lead, major pharmaceutical stocks in the US market rose in pre-market trading. Giants with oncology pipelines, such as BMS, Pfizer, and AstraZeneca, saw gains between 1% and 3%. The pharmaceutical sector had previously underperformed the broader market in the first half of 2026, with a cumulative gain of only 4.2%, far below the S&P 500 index's 9.8%. This was mainly due to policy pressures from US drug pricing reforms. However, recent positive clinical results and M&A activities are prompting some institutional capital to re-evaluate the sector.
Capital flow data also confirms this shift. As of pre-market today, the ETF tracking the healthcare sector—XLV—experienced high volume during pre-market trading, with a net inflow exceeding $230 million, the largest in the last three trading days. Some traders noted that this round of capital is like a "defensive offensive," valuing both the valuation discount and the new product cycle.
Market Impact: S&P 500 Futures Surge, But Tech Stocks Remain Calm in Early Trading
At the macro level, S&P 500 index futures rose by 0.4% pre-market, boosted by news from Merck, before narrowing to around 0.2%. Dow futures saw a slight increase due to the significant weighting of the pharmaceutical sector in the Dow. Tech stock futures were stable in the early session, with the Nasdaq 100 index futures essentially flat. There was no clear style rotation in the market, but investor focus clearly shifted to fundamental events.
Some analysts point out that as the earnings season gradually winds down in late July, major news from individual companies will be the main source of market volatility. Today's movement in Merck is a typical example of a "single-stock event-driven" trend. This type of trend is often more resilient because it is based on substantive drug data rather than mere speculative expectations.
Outlook: Focus on Approval Progress and Sales Volume
Moving forward, the market will closely monitor the release of the complete trial data at subsequent medical conferences and whether the FDA will expand the indications for KEYTRUDA based on this data. Several investment banks have issued quick reviews, with JPMorgan raising its target price for Merck from $190 to $215 while maintaining an "Overweight" rating, believing the data could initiate a second growth curve. Goldman Sachs, however, reminds investors to carefully evaluate the accessibility and pricing environment of the therapy in the real world.
For general US stock investors, the long-term logic of the pharmaceutical sector has not changed, but stock selection must place greater emphasis on pipeline value. Today's unusual movement in Merck can be seen as an interesting observation window—that medical innovation can also bring substantial returns outside of high volatility in technology stocks. We will continue to track the marginal impact of this event on the broader market and industry funds during our live broadcast.
Risk Disclosure: The above content does not constitute investment advice. Stock market investment involves risks, and caution is advised before entering the market.
