Update (4:20 p.m.): Updated with Tuesday market close information.

NEW YORK (TheStreet) -- Achillion Pharmaceuticals  (ACHN) - Get Report surged for a second consecutive day on Tuesday after the FDA removed its clinical hold on sovaprevir, one of Achillion's four experimental hepatitis C treatments.

The FDA had placed the hold in June because of abnormal liver results in patients. Achillion can now begin trials with a once-daily maximum dose of 200 mg of sovaprevir in hepatitis C patients and other healthy volunteers. 

The company also announced it had begun initial dosing with ACH-3422, another of its experimental hepatitis C treatments.

Must Read: Achillion Hep C Drug Update is Well Timed

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Achillion surged Monday amid news that Merck (MRK) - Get Report 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) - Get Report and Abbvie (ABBV) - Get Report 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.

The stock closed up 83.29%, or $3.54, to $7.79. More than 69.6 million shares changed hands, which dwarfed the average volume of 2,128,800.

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

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