Scientists are a step closer to finding the first effective treatments for the deadly Ebola hemorrhagic fever after two potential drugs showed encouraging survival results in a clinical trial in Congo.

Two experimental drugs — Regeneron's REGN-EB3 and a monoclonal antibody called mAb114 — were both developed using antibodies harvested from survivors of Ebola infection.

They showed "clearly better" results in patients in a trial of four potential treatments being conducted during the world's second-largest Ebola outbreak in history, now entering its second year in the Democratic Republic of Congo.