Drug advances for sleeping sickness included Germanin and tryparsamide. They also investigated the used of tryparsamide as a possible treatment for syphilis. Variants of tryparsamide, as Flexner named it, continue to be administered today. Tryparsamide was a standard treatment for syphilis until penicillin replaced it in 1950. Tryparsamide proved successful in combating the fatal epidemic, curing 80% of cases. Nonetheless, tryparsamide became the drug of choice for chemotherapy of sleeping sickness for several decades.