A Phase IIA and IIB clinical trial of a quantified extract of Nauclea pobeguinii stem bark against uncomplicated falciparum malaria

In a clinical study of type IIA, the quantified 80% ethanol extract from the stem bark of Nauclea pobeguinii (Pobég.) E.M.A. Petit containing 5.6% strictosamide appeared to be effective in the treatment of uncomplicated falciparum malaria when taken for seven days, at a dose regimen of two 500mg capsules three times daily for 3 days, followed by one 500mg capsule three times daily for four days. No serious side effects were noted. The Phase IIA clinical trial was carried out according to the WHO 14 days test (WHO 2003) and the results revealed that all eleven patients were completely cleared of parasitaemia and fever on days 3, 7 and 14, except for one patient.

In a Phase IIB study designed as a single blind prospective trial in 65 patients with proven P. falciparum malaria, the efficacy and safety of the extract was compared with an artesunate-amodiaquine (AS + AQ) combination as the second arm. Evaluated on the evidence of fever clearance, disappearance of parasitaemia and other symptoms and adequate clinical and parasitological responses (ACPR), according to the WHO criteria (WHO 2003), both treatments were effective in the treatment of uncomplicated malaria. AS + AQ appeared to be slightly more effective while the extract was better tolerated. All these results suggest that the quantified 80% ethanol extract from the stem bark of Nauclea pobeguinii should be considered as a candidate for a clinical trial Phase III.

Keywords: Nauclea pobeguinii, quantified extract, clinical trial IIA, clinical trial IIB, malaria