Efficacy and safety of tribendimidine versus praziquantel against Opisthorchis viverrini in Laos: an open-label, randomised, non-inferiority, phase 2 trial

• Published in: The Lancet infectious diseases 2018-02, Vol.18 (2), p.155-161
• Main Authors: Sayasone, Somphou, Keiser, Jennifer, Meister, Isabel, Vonghachack, Youthanavanh, Xayavong, Syda, Senggnam, Kanpaseuth, Phongluxa, Khampheng, Hattendorf, Jan, Odermatt, Peter
• Format: Article
• Language: English
• Subjects: Administration, Oral; Adolescent; Adolescents; Adult; Adults; Aged; Aged, 80 and over; Analysis; Animals; Anthelmintics - administration & dosage; Anthelmintics - adverse effects; Child; Children; Chronic illnesses; Clinical trials; Clonorchis sinensis; Confidence intervals; Drug dosages; Drug-Related Side Effects and Adverse Reactions - epidemiology; Drug-Related Side Effects and Adverse Reactions - pathology; Eggs; Ethics; Feces - parasitology; Female; Global health; Headache; Health services; Humans; Infections; Infectious diseases; Laboratories; Laos; Liver; Male; Medical diagnosis; Medical research; Middle Aged; Nausea; Odor; Opisthorchiasis - drug therapy; Opisthorchis - drug effects; Opisthorchis viverrini; Parasite Egg Count; Parasites; Phenylenediamines - administration & dosage; Phenylenediamines - adverse effects; Physicians; Praziquantel; Praziquantel - administration & dosage; Praziquantel - adverse effects; Product development; Randomization; Reduction; Safety; Schistosoma; Studies; Systematic review; Teenagers; Treatment Outcome; Tropical diseases; Vertigo; Young Adult
• ISSN: 1473-3099; 1474-4457
• DOI: 10.1016/S1473-3099(17)30624-2

Praziquantel is the only option for treatment of the liver fluke infection Opisthorchis viverrini. Tribendimidine could be an alternative drug. We aimed to assess the efficacy and safety of a single, oral dose of tribendimidine, compared with praziquantel administered in two doses, in participants with O viverrini infection. We did an open-label, randomised, non-inferiority, phase 2 trial in children (8–14 years) and adolescents and adults (≥15 years) in Champasack province, southern Laos. Participants infected with O viverrini were randomly assigned (1:1), via a computer-generated block-randomisation procedure (block sizes of two, four, and six), to receive a single, oral dose of tribendimidine (200 mg for children, 400 mg for adolescents and adults) or two oral doses of praziquantel (50 mg/kg bodyweight and 25 mg/kg bodyweight, 6 h apart). Physicians assessing adverse events and laboratory personnel were masked to treatment allocation, but the investigators administering treatment and the participants could have recognised the treatment group based on differences in the number, appearance, and odour of the tablets. The primary outcomes were cure rate, defined as no parasite eggs in stool at 3 weeks' follow-up, and egg reduction rate. We did available-case analysis of all participants with primary endpoint data. The non-inferiority margin for the difference in cure rates between the groups was pre-specified as −3 percentage points. Adverse events were monitored at 3 h and 24 h after treatment. This trial is registered, number ISRCTN96948551. Between Feb 1, and April 30, 2014, we assigned 607 participants with confirmed O viverrini infection to receive tribendimidine (n=300) or praziquantel (n=307). 11 participants (five in the tribendimidine group and six in the praziquantel group) did not provide stool samples at 3 weeks' follow-up and were excluded from the available-case analysis. 276 (93·6%) of 295 participants in the tribendimidine group were cured compared with 293 (97·3%) of 301 participants in the praziquantel group. The difference in cure rates between the two groups was −3·8 percentage points (95% CI −7·1 to −0·4), thus the lower limit of the confidence interval exceeded the non-inferiority margin. In both treatment groups, egg reduction rates were 99·9%. Adverse events were of mild and moderate intensity and were more frequent in the praziquantel group than in the tribendimidine group (odds ratio 4·5, 95% CI 3·2–6·3; p