Merck & Company invested millions of dollars to develop a treatment for river blindness, a disease of the developing world that has infected 18 million people and poses a risk for 127 million people. River blindness is caused by the bite of black flies that deposit larvae of a parasite under the skin of their victims. When the larvae mature into adult worms, the adults reproduce millions of the immature forms of the parasites that migrate throughout the tissues of the body causing severe and never-ending