Merck & Co.'s Stock Soars on Japan Approval of Keytruda QLEX

Merck & Co.'s stock price has reached near recent highs following Japan's Ministry of Health, Labor and Welfare approval for its Keytruda QLEX subcutaneous formulation on September 21, 2026. The new dosing option is a more convenient alternative to the standard infusion method.

The approval adds to Keytruda's growing franchise in Japan, which already includes several indications for solid tumors. Merck highlighted that the subcutaneous administration can shorten treatment time and provide patients with greater flexibility.

As of September 21, 2026, Merck & Co.'s stock traded at around $148 on the New York Stock Exchange, representing a daily gain of approximately 0.8% following the regulatory news in Japan. Over the past year, the shares have increased by nearly 40%, moving closer to their 52-week high.

Analysts remain optimistic about Merck's prospects, with some predicting further gains. Morgan Stanley analyst Terence Flynn maintained a Buy rating on Merck with a price target of $179.00, implying a potential upside of around 21.9% from the current price.