Additional Info

Poster on Impamel I/II:

Impamel I

Improved application for melarsoprol, clinical efficacy


Human African trypanosomiasis (sleeping sickness) is an important endemic disease in sub-Saharan Africa. The disease is fatal if left untreated and poses a tremendous socio-economic burden to the patients, their families and the communities. Due to the lack of suitable alternatives, the majority of patients suffering from the late-stage of the disease are treated with the more than 50-year-old organoarsenical drug melarsoprol (Arsobal®). Until recently, the knowledge of the pharmacological and pharmacokinetic properties of melarsoprol was much limited and the treatment generally complicated and not standardised throughout Africa.

Researchers at STI have elucidated the pharmacologic and pharmacokinetic properties of melarsoprol. Subsequently a new, concise treatment protocol proposed with an abridged duration of only 10 days (10 x 2.2 mg/kg/day) compared to 25– 35 days before. After successful preliminary clinical testing, the concept of the new schedule was confirmed in an open, randomized equivalence trial with 500 patients conducted in Angola between 1997-1999, comparing the efficacy and safety to those of standard melarsoprol treatment. No difference in the primary outcomes was found, i.e. death in temporal relationship to treatment, frequency of encephalopathic syndromes and relapse rates. An increase of skin reactions was observed under the new treatment. They could be controlled by additional medication and/or treatment interruption, remitted completely and were not considered a significant problem by the investigators.


Given the economic and practical advantages of the concise treatment protocol, the national control programs and those involved in treatment and control of the disease asked for a thorough assessment of the 10-day schedule under less controlled conditions in the field, i.e. in rural treatment centre settings.