(Reuters) - Antares Pharma Inc said the U.S. Food and Drug Administration has asked for additional safety data on its testosterone drug after a patient developed allergic reaction in a mid-stage trial.
The company’s shares fell as much as 11 percent on concerns that the regulator’s request could delay the marketing application for the drug.
Antares said on Tuesday that 70 more patients would need to be treated with its experimental drug, QuickShot Testosterone, for six months to meet the FDA’s request for safety data on 350 patients.
However, Oppenheimer & Co analyst Akiva Felt said the FDA’s request was not a “crippling delay”.
He said the additional studies could be completed within a period of 9-12 months.
Antares said it would release data from the current late-stage study in the second quarter of 2015.
The company said a patient developed hives, an allergic reaction that causes red, itchy bumps on the skin, during the mid-stage study.
QuickShot Testosterone, or QST, is the only self-administered experimental subcutaneous treatment in late-stage trials. This gives QST an edge over approved injectable testosterone products, which are intramuscular and must be administered by a doctor.
The FDA has become more cautious about approving testosterone treatments, after it found late last year that more than a fifth of those prescribed such drugs did not test their testosterone levels before or during treatment.
Prescriptions for “Low T,” as low testosterone has been described in TV commercials, have soared over the past decade, driven by an increase in use by middle-aged men with lowered testosterone levels related to advancing age.
The company’s shares were down 9.1 percent at $2.37 in afternoon trading on the Nasdaq.
Reporting by Amrutha Penumudi in Bengaluru; Editing by Saumyadeb Chakrabarty and Sriraj Kalluvila