Enanta Pharmaceuticals, a biotech focused on developing small molecule drugs to use against hepatitis C, filed on Tuesday with the SEC to raise up to $69 million in an initial public offering. The Watertown, MA-based company, which booked $40 million in sales for the 12 months ended 6/30/2012, plans to list on the NASDAQ under the symbol ENTA. J.P. Morgan and Credit Suisse are the joint bookrunners on the deal. No pricing terms were disclosed.