NEW YORK (AP) -- Shares of Achillion Pharmaceuticals Inc. climbed nearly 16 percent Wednesday after two analysts put "Buy" ratings on the stock, and shares of competing hepatitis C drug developer Idenix Pharmaceuticals Inc. fell following a downgrade.
Analysts for Deutsche Bank and BofA Merrill Lynch had positive views of Achillion's two-drug regimen, which combines its drug candidates sovaprevir and ACH-3102.
Achillion is one of several companies trying to develop a hepatitis C regimen that doesn't include the drug interferon. Interferon has long been a part of hepatitis C treatment, but it can cause serious side effects, including flu-like symptoms that can last for months.
BofA analyst Rachel McMinn upgraded Achillion shares to "Buy" from "Underperform" with a price target of $13 per share. McMinn wrote that Achillion's two-drug hepatitis C regimen could be an effective low-cost option for treating the disease.
Deutsche Bank analyst Alethia Young began coverage of the stock with a "Buy" rating and a price target of $12 per share, saying peak sales of the drugs could reach $2.7 billion per year.
"We believe Achillion has hepatitis C drugs that will be very competitive in a big HCV market," Young wrote. Shares of Achillion rose $1.31, or 16.2 percent, to $9.41 in afternoon trading.
Achillion shares rose $1.29, or 15.9 percent, to $9.39 in afternoon trading.
Meanwhile, Idenix shares declined again Wednesday after McMinn downgraded it to "Neutral" from "Buy." The stock has slumped on concerns that two of its drugs may harm patient's hearts.
On Aug. 1, drugmaker Bristol-Myers Squibb Co. stopped a trial of an experimental hepatitis C drug because one clinical trial patient died of heart failure. Since then the Food and Drug Administration has halted studies of two Idenix drugs because of concerns they could damage patients' hearts. Shares of Idenix are down 44 percent since Aug. 1.
The stock lost 54 cents, or 9.6 percent, to $5.10 in afternoon trading.