Clinical Trial of Bilhvax,a Vaccine Candidate Against Schistosomiasis
Condition: Schistosomiasis; Bilharziasis; Urinary Schistosomiasis
MeSH terms: Schistosomiasis; Schistosomiasis haematobia
Study type: Interventional
Phase: Phase 1

Summary: 
      The purpose of this clinical study is to evaluate safety and immunogenicity in adult healthy
      volunteers of the vaccine candidate against schistosomiasis named Bilhvax.
    

Detailed description: 
      The development of an efficient vaccine against human schistosomiasis represents a major
      challenge for the improvement of health in many developing countries.

      Schistosomiasis affects millions people in numerous countries and hampers economical
      development of tropical areas.

      Although progress has been made for the limitation of the disease severity by chemotherapy,
      continuous re-infection and risks of drug resistance point to the necessary development of
      alternative strategies.

      It is widely agreed that immunological prevention of chronic parasitic infections will be
      extremely difficult to achieve. Conversely in some major helminth infections like
      schistosomiasis, where parasite eggs laying in the tissues is the exclusive cause of
      pathology and the elimination of eggs in nature is the source of transmission, inhibition of
      parasite fecundity might represent for the future a novel way to prevent the deleterious
      effects of these chronic infections in man.

      The concept to target by vaccination the cause of the pathology rather than the parasite
      itself would provide a potent tool to control a major chronic infection.

      After years of basic studies on effector and regulatory mechanisms of immune response against
      schistosomiasis it has been identify a schistosome molecule named glutathione S-transferase
      28 kDa (28GST) presenting a potential as vaccine candidate.

      This 28GST have been cloned and named Bilhvax. It has been shown that immunization with such
      schistosome GST would dramatically decrease female worm fecundity and egg viability in
      various hosts. It was demonstrated that these anti-fecundity effects are associated with the
      production of antibodies neutralizing the GST enzymatic activities obtained through a
      Th2-type immune response. This correlation between anti-fecundity effects and
      inhibition-mediated antibodies demonstrated in several animal models was re-enforced by
      epidemiological studies showing that such acquired antibodies produced during infection could
      be detected in adult individuals naturally resistant to the re-infection.

      The present phase 1 clinical trial is conducted in healthy Caucasian volunteers to evaluate
      as primary endpoint the safety of the recombinant Sh28GST (rSh28GST) in Alum (named Bilhvax),
      a vaccine candidate against human urinary schistosomiasis. The secondary endpoint is to
      evaluate immunogenicity of Bilhvax, to determine the profile of the immune response, and to
      estimate the neutralizing capacity of the antibodies against the rSh28GST enzymatic activity.

      The recombinant S. haematobium 28GST expressed in yeast is produced by Eurogentec SA in GMP
      conditions.
    

Intervention name(s): rSh28GST
Intervention type(s): Biological
Intervention description(s): subcutaneous route at Day 0, Day 28, and Day 150 for the third administration of 100µg for Arm 1
Other intervention name(s): Bilhvax
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Prevention
Keywords: vaccines; safety; drug tolerance; immunogenic protein; antibody response; cytokine