By George Glover

Crinetics Pharmaceuticals stock was surging on Tuesday after Vertex Pharmaceuticals said it had agreed to buy the biotech for $10 billion.

Shares of Crinetics jumped 99% to $83.52 ahead of the opening bell. Vertex slid 2.2%. The S&P 500 was 0.2% lower.

Vertex said in a press release late Monday that it would buy Crinetics, which specializes in discovering and developing treatments for endocrine diseases, for $85 a share in cash. The deal is expected to close sometime this quarter.

The deal is the latest in a flurry of pharma transactions this year, as companies scramble to replenish their drug pipelines by purchasing smaller biotechs that may have promising medications.

Crinetics stock closed at just over $42 on Monday, meaning that Vertex is buying the company at a premium of more than 100%.

It might not be overpaying. Vertex expects Crinetics assets, including acromegaly treatment Palsonify and endocrine disorder drug Atumelnant, to grow its annual revenue by $5 billion. Vertex reported total revenue of $12 billion last year.

"The fit is clear, given existing expertise in specialty markets, serious diseases, causal biology, and measurable biomarkers," Citi analyst Geoff Meacham said. "The $5 billion peak sales framing adds another route to sustain double-digit topline growth."

Meacham rates Vertex at Buy, with a $585 price target that implies the stock can jump 10% from its level as of Monday's close.

Write to George Glover at george.glover@dowjones.com

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