WATERTOWN, Mass.--(BUSINESS WIRE)--Enanta Pharmaceuticals, Inc., (NASDAQ:ENTA), a research and development-focused biotechnology company dedicated to creating small molecule drugs for viral infections and liver diseases, announced today that it has expanded its research and development programs within the company’s core focus areas of virology and liver disease to include new programs to treat hepatitis B virus (HBV) and respiratory syncytial virus (RSV) infections.