Abbott Laboratories ($ABT) shed more light on a promising mid-stage study of its interferon-free treatment for hepatitis C, showing the company is among the leaders in the crowded race to advance new all-oral therapies against the liver-damaging virus. After impressing analysts with topline results last month, Abbott revealed today that its triple-combo of antiviral drugs offered slightly better efficacy when given with ribavirin than without in its Phase IIb "Aviator" study. Story