PfSPZ Challenge in Healthy Malaria-Naïve Adults in the United States
Condition: Plasmodium Falciparum Infection
MeSH terms: Malaria
Study type: Interventional
Phase: Phase 1

Summary: 
      This phase I trial of the replication-intact PfSPZ Challenge vaccine given under CQ cover
      will enroll 28 healthy volunteers to receive PfSPZ or placebo, as well as suppressive doses
      of chloroquine (CQ)on varying schedules. 10 weeks post 3rd immunization subjects will be
      subjected to controlled human malarial infection. The primary objective of this study is to
      evaluate the safety and tolerability of escalating doses of Sanaria PfSPZ Challenge
      administered by DVI on varying schedules to healthy malaria-naïve adults taking suppressive
      doses of CQ (PfSPZ-CVac).
    

Detailed description: 
      This phase I trial of the replication-intact PfSPZ Challenge vaccine given under CQ
      (PfSPZ-CVac) cover will randomize 28 healthy adult participants to one of three cohorts.
      Group 1 (n=12) will be randomized to receive PfSPZ Challenge vaccine at a dose of 51,200
      sporozoites or 0.5 mL of sterile normal saline placebo by DVI on Days 3, 10 and 17. Group 2
      (n=4) will be randomized to receive PfSPZ Challenge vaccine at a dose of 102,400 sporozoites
      or 0.5 mL of sterile normal saline placebo by DVI on Days 3, 10, and 17. Within both groups,
      placebo will be assigned 1:3, with blinded allocation to the two treatments within each
      group. All subjects in Study Groups 1 and 2 will receive, by directly observed treatment
      (DOT), oral chloroquine (CQ) on Days 1, 8, 15, and 22 at a suppressive dose of 600 mg base on
      Day 1 and 300 mg base on Days 8, 15 and 22. All subjects in Group 3 (n=9) will receive PfSPZ
      Challenge vaccine at a dose of 102,400 sporozoites per administration, with vaccine given on
      a Day 1, 6, and 11 schedule. Subjects in Group 3 will also receive, by DOT, oral CQ, with a
      suppressive dose of 600 mg base on Day 1 and a dose of 300 mg base on Days 6, 11, and 16. At
      10 weeks after the third administration of study vaccine or placebo, all subjects within the
      three groups will receive the PfSPZ Challenge by direct venous injection at a dose of 3,200
      P. falciparum sporozoites to assess vaccine efficacy against controlled human malarial
      infection (CHMI). The primary objective of this study is to 1) evaluate the safety and
      tolerability of escalating doses of Sanaria PfSPZ Challenge administered by DVI on varying
      schedules to healthy malaria-naïve adults taking suppressive doses of CQ (PfSPZ-CVac).
    

Intervention name(s): Chloroquine; PfSPZ (NF54) Challenge; Placebo
Intervention type(s): Drug; Biological; Other
Intervention description(s): Administered as 600mg PO, day 1, 300mg PO days 8, 15, 22.; Cryopreserved Plasmodium falciparum (Pf) fully infectious sporozoites (SPZ) that have been developed to be used to infect volunteers in controlled human malaria infection (CHMI) to assess the efficacy of antimalarial drugs and vaccines. The PfSPZ (NF54) Challenge contains a laboratory malaria strain isolated from a Dutch traveler to Africa.; Placebo
Intervention MeSH terms: Chloroquine
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Prevention
Keywords: challenge; malaria; P. falciparum; PfSPZ; sporozoites; vaccine