Safety and Immunogenicity Study of Plasmodium Vivax CS Derived Synthetic Peptides Formulated in Two Adjuvants
Condition: Malaria, Vivax
MeSH terms: Malaria; Malaria, Vivax
Study type: Interventional
Phase: Phase 1

Summary: 
      This was a phase I double blind controlled vaccine trial, evaluating safety, tolerability and
      immunogenicity of mixtures of N, R and C LSP derived from the P. vivax CS protein formulated
      in two adjuvants Montanide ISA 720 and Montanide ISA 51.

      The primary objective was to assess in malaria-naïve adults, the safety and reactogenicity of
      these peptides formulated in the two adjuvants

      We recruited 40 healthy men and women volunteers from Cali, Colombia, a city non-endemic for
      malaria. Volunteers were 19--41 years of age and had no history of malaria. During a period
      of three months a total of 100 volunteers were assessed for eligibility criteria in order to
      select a total of 40 volunteers willing to participate in the clinical trial. By consecutive
      allocation, eight participants were allocated to each of the five experimental groups (A--E):
      four groups (A--D) were immunized with the vaccine formulations at two different dose
      concentrations and formulated in two different adjuvants. A control group (E) was injected
      with placebo (saline solution)
    

Detailed description: 
      The study corresponds to a clinical trial, randomized double-blind, controlled, dose
      escalation, Phase IB, which will assess the safety and immunogenicity of a mixture of
      synthetic peptides derived from CS protein of P. vivax, formulated in adjuvant Montanide ISA
      720 and 51; in healthy men and nonpregnant women without previous history of malaria
      infection.

      In order to optimize the vaccine dose, eligible participants were enrolled to receive three
      doses of vaccine containing peptide mixtures at a dose of 50 ug or 100 ug of each individual
      peptide, for a final dose of 150 ug or 300 ug respectively, in a volume of 0.5 mL. The
      previous clinical trial had indicated that doses between 30 ug and 100 ug produced better
      responses than lower doses. The first immunization dose (given at Month 0) contained the
      peptides N and C only, whereas the two boosting doses (given at Months 2 and 4) contained all
      three (N, R, and C) peptides (Table 1). Vaccination was performed by intramuscular injection
      in the deltoid muscle, alternating arms with each injection.

      For safety reasons, participants assigned to the low vaccine dose groups were immunized first
      and only two weeks after initiation when no serious adverse events (SAE) had occurred,
      immunization of participants in the high-dose was started. Half of the participants assigned
      to receive placebo were immunized along with each dose level group. Clinical monitors and the
      IRBs of the University of Valle and IMC, evaluated the occurrence and severity of adverse
      events (AE) associated with immunization. The occurrence of more than three AE (severity
      grade 2 or higher) or one SAE related to the vaccine would have led to study termination.
      Participants who left the study were not replaced.
    

Intervention name(s): Peptides (N,R&C) formulated in Montanide ISA 720; Peptides (N,R&C) formulated in Montanide ISA 51; Peptides (N,R&C) formulated in Montanide ISA 720; Peptides (N,R&C) formulated in Montanide ISA 51; Placebo
Intervention type(s): Drug; Drug; Drug; Drug; Other
Intervention description(s): 50 ug; 50 ug; 100 ug; 100 ug; PLacebo: Isotonic saline solution
Other intervention name(s): Peptides (N, R & C) from P. vivax CS protein; Peptides (N, R & C) from P. vivax CS protein.; Peptides (N, R & C) from P. vivax CS protein.; Peptides (N, R & C) from P. vivax CS protein
Intervention MeSH terms: Mannitol; Monatide (IMS 3015); Freund's Adjuvant
Allocation: Randomized
Intervention model: Factorial Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Keywords: Malaria; Synthetic peptides; Plasmodium vivax; Human volunteers