Study of Safety and Immune Response of the Sm14 Vaccine in Adults of Endemic Regions

Safety and Immunogenicity Evaluation of the Vaccine Candidate Sm14 in Combination With the Adjuvant Glucopyranosyl Lipid A (GLA-SE) in Adults Living in Endemic Regions for S. Mansoni and S. Haematobium in Senegal. A Comparative, Randomized, Open-label Trial

The clinical trial phase 2a is designed to assess the safety of the active ingredient (protein + adjuvant) and secondarily its immunogenicity in healthy male adults from 18 to 49 years of age with a history of infection with intestinal and urinary schistosomiasis, living in the Valley of the Senegal River, a highly endemic area for schistosomiasis. Two arms in the study will test different doses of GLA-SE adjuvant (2.5 and 5 μg). This phase IIA in adults is considered to be a preliminary step in safety before starting trials in children in endemic areas to S. mansoni or S. haematobium, target population of the vaccine.

A phase 2a trial, self-contained, open-label, randomized, dose-escalation study in two parallel arms receiving three (3) injections at D0, D28, D56; both groups receiving 50 μg Sm14 vaccine candidate solution, either combined with 2.5µg GLA-SE for the first group and 5µg for the second one in adults living in a S. mansoni and S. haematobium endemic area.

Sm14: recombinant protein produced in yeast following Good Manufacturing Practices (GMP) conditions, presented in vials containing 0.55 ml solution Sm14, 0.4 ml solution is diluted with 0.4 ml of GLA (Synthetic Glucopyranosyl lipid A) for intramuscular administration.

Medical examinations are performed at D0 (before injection, 1 hr and 4 hr after), and a safety evaluation at 24 hrs and 48 hrs, after each injection.

Blood analysis: Liver function tests - renal function tests - blood counts, at W-1 before inclusion, and then 7 days after each injections and at W13 and W21 during the follow-up.

Blood samples for immune response analysis at time of each injection, and then W12 and W20.

Inclusion Criteria:

• Adults, male, 18 to 49 years old (inclusive) at the time of inclusion.
• Living in one of selected villages in Saint-Louis Region (Senegal).
• Free of obvious/severe health problems except schistosomiasis, as established by clinical examination and blood analysis, i.e. hematological exams, liver and renal function tests.
• Written informed consent to participate obtained
• Treated with 40mg/kg Praziquantel (PZQ) before inclusion (W-5 to W-4 before the first injection) in case of infection with S. mansoni and S. haematobium
• Residence in the area during the period of the study.

Exclusion Criteria:

• Adult who does not respond to one of the inclusion criteria
• Current or previous chronic administration (defined as more than 14 days) of immunosuppressive drugs or other immuno-modifying drugs.
• Known hypersensitivity to any component in the Sm14 vaccine or history of allergic disease.
• Knowledge of non-infectious chronic disease
• Acute disease at time of enrollment.
• Other conditions which in opinion of the PI may potentially represent a danger for the patient to be enrolled.
• Non residence in the study area or intent to move during the study period