A total of 288 subjects were enrolled and 287 completed this study. In this completed Phase III trial, children aged 3 months to 6 years infected with S. mansoni or S. haematobium were enrolled in different age groups and treated with a single dose of arpraziquantel. High efficacy was observed with cure rates close to or above 90% for S. mansoni (at a dose of 50 mg/kg) and S. haematobium (at a dose of 60 mg/kg). The primary endpoint of clinical cure, defined as no parasite eggs in the stool (S. mansoni) 17 to 21 days after treatment or urine (S. haematobium) 17 to 21 days and additionally 35 to 40 days after treatment, met the pre-specified success criteria:

• Cure rates in all age groups for all arpraziquantel 50 mg/kg treated S. mansoni infections have point estimates ≥88% with lower limit of the 95% CI >70%

• Cure rates for arpraziquantel 60 mg/kg treated S. haematobium infection have point estimates ≥ 86% with lower limit of 95% CI >70% (Cohort 4b, weeks 3 and 5) 

High Egg Reduction Rate (ERR) in all dose groups and across both species (≈99%)

Arpraziquantel treatment at both doses (50 mg/kg and 60 mg/kg) demonstrated favorable safety, tolerability and improved palatability among preschool-aged children. No new potential risks or safety concerns were identified.

Schistosomiasis is an acute and chronic parasitic disease caused by 5 main species of blood flukes (trematode worms) of the genus Schistosoma. Infection occurs when larval forms of the parasite released by freshwater snails penetrate the skin during contact with infested water. Three major endemic areas for schistosomiasis are recognized in Kenya; the Lake Victoria basin (main species is Schistosoma mansoni), Coastal region (S. haematobium) and lower Eastern and Taveta areas (both S. mansoni and S. haematobium). The WHO recommended control strategy of schistosomiasis is based on preventive chemotherapy interventions targeting the majority of the at-risk population. The current gold standard treatment employs annual single oral dose of the drug Praziquantel (PZQ) 600 mg tablets for adults and school aged children at 40 mg/kg. However, pre-school aged children (pre-SAC), which are a high-risk group for schistosome infections accounting for 10-20 million of the global prevalence, are currently not included during treatment campaigns due to the lack of a suitable PZQ pediatric formulation. This phase III clinical trial seeks to assess the efficacy and safety of a single dose of the new L-praziquantel orally disintegrating tablets (ODT) in children age 4 to 6 years infected with S. mansoni; the efficacy and safety of the ODTs in children age 3 months to 4 years infected with S. mansoni; and the efficacy and safety of the ODT in children age 3 months to 6 years infected with Schistosoma haematobium (urogenital schistosomiasis) in Homa Bay and Migori Counties, western Kenya. This open-label, randomized, controlled study includes single dose treatments in 4 cohorts (C1-C4) based on age and Schistosoma species of infection: C1a (50 mg/kg L-PZQ ODT, n = 24, 4 to 6 years infected with S. mansoni), C1b (40 mg/kg crushed commercial PZQ, n = 11, 4 to 6 years infected with S. mansoni), C2 (50 mg/kg L-PZQ ODT, n = 15, 2 to 3 years infected with S. mansoni), C3 (50 mg/kg L-PZQ ODT, n = 20, 3 to 24 months infected with S. mansoni) and C4 (50 mg/kg L-PZQ ODT, n = 60-90, 3 months to 6 years infected with S. haematobium). After 30 patients in C4 are treated, the efficacy data will be summarized and evaluated by the IDMC to decide on whether to increase the dose to 60 mg/kg. If a dose increase is needed, 30 additional patients will be added to this cohort (i.e., total sample size of 90). This study will improve disease management through recommendations for a change in current schistosomiasis treatment policy by extending existing preventive chemotherapy programs to younger children through access to a PZQ-ODT formulation.

​