Safety and Immunogenicity Study of Plasmodium Vivax CS Derived Synthetic Peptides Formulated in Two Adjuvants — Fase1B  

Malaria, Vivax Clinical Trial

Official title: Malaria Vaccine Phase IB Clinical Trial: Safety and Immunogenicity Study of Plasmodium Vivax CS Derived Synthetic Peptides Formulated in Two Adjuvants

Status Completed

Clinical Trial 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)

Clinical Trial 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. ;

Study Design

Allocation: Randomized, Intervention Model: Factorial Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)

Related Conditions & MeSH terms

• Malaria
• Malaria, Vivax

• NCT number: NCT01081847
• Study type: Interventional
• Source: Malaria Vaccine and Drug Development Center
• Status: Completed
• Phase: Phase 1
• Start date: July 2005
• Completion date: April 2006