Fujifilm Holdings Corp said on Tuesday that it expects its influenza drug Avigan to become a highly effective drug to treat Ebola.

"So far, four Ebola patients have recovered after being treated with the drug," Shigetaka Komori, Fujifilm's chairman and chief executive, told a news conference. "We believe that the drug will become highly effective to treat the disease."

Fujifilm, once among the world's biggest makers of photography film, has been expanding its pharmaceutical business. In 2008 it bought Toyama Chemical Co, whose influenza drug Avigan has been drafted for the fight against Ebola.