Pieris Pharmaceuticals, Inc. (NASDAQ: PIRS), a biotechnology company advancing its proprietary Anticalin biotherapeutic technologies, today announced that it closed the sale of an additional 1,211,827 shares of its common stock at the public offering price of $2.75 per share pursuant to the over-allotment option exercised by the underwriters of its recently completed public offering. Including proceeds from the exercise of the over-allotment option, total gross proceeds to Pieris from the offering were $28.3 million before deducting the underwriting discounts, commissions and estimated expenses.