Feb 23 (Reuters) - Merck said on Monday it would split its human-health business into two units, creating a division for its cancer franchise led by blockbuster drug Keytruda while grouping its non-oncology medicines separately.

The restructuring underscores the U.S. drugmaker's push to diversify beyond Keytruda amid the drug's looming loss of exclusivity later this decade.

Keytruda, approved for several forms of cancers, is the best selling prescription medicine in the world. The treatment generated more than $30 billion in 2025 and accounted for nearly half of the company's total revenue.

Merck shares were up 1.4% in premarket trading.

The company has tripled its pipeline since 2021 and struck two deals in the $10 billion range last year, buying Cidara Therapeutics and Verona Pharma to broaden its portfolio.

The split follows Merck's downbeat 2026 forecast issued earlier this month, where it warned of lower-than-expected sales and profit as several legacy drugs near loss of exclusivity and face generic pressure.

Merck also appointed Jannie Oosthuizen as executive vice president and president of the cancer business. Oosthuizen most recently served as senior vice president and president of Merck Human Health U.S., where he led strategy and commercialization for the company's U.S. portfolio.

The news of the split was first reported by the Wall Street Journal earlier in the day.