Why Achillion Pharmaceuticals (ACHN) Stock Is Up Today (Update)

Update (4:10 p.m.): Updated with Monday market close information.

NEW YORK (TheStreet) -- Achillion Pharmaceuticals  (ACHN) surged Monday amid news that Merck  (MRK) would purchase biotechnology company Idenix Pharmaceuticals  (IDIX) for $3.85 billion as it tries to strengthen its position in the increasingly competitive hepatitis C sector.

Achillion could be the next acquisition target for larger companies. CNBC reported Johnson & Johnson  (JNJ) and Abbvie  (ABBV) were both interested in buying Idenix but Merck secured the purchase. Those companies, among others, could now turn their focus to Achillion, which has a pipeline of hepatitis C drugs.

Merck will pay $24.50 a share in cash for Idenix, more than triple the company's closing price of $7.23 on Friday.

Must Read: Achillion Pharma Might be Next Hep C Takeout Target

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"Idenix has established a promising portfolio of hepatitis C candidates,'' said Dr. Roger Perlmutter, the president of Merck Research Laboratories, in a statement Monday. 

Achillion stock closed up 47.57%, or $1.37, to $4.25. More than 46.9 million shares changed hands, which eclipsed the average volume of 1,420,150.

For more on the Achillion story, read TheStreet's Adam Feuerstein's article here.

ACHN Price Chart

ACHN Price data by YCharts

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