Safety and Protective Efficacy of IV Immunization With Cryopreserved PfSPZ Under A/P Chemoprophylaxis
Status:
Completed
Trial end date:
2017-11-16
Target enrollment:
Participant gender:
Summary
Single center, randomized, placebo-controlled, double-blinded trial using PfSPZ Challenge
(NF54) under A/P chemoprophylaxis for immunization and PfSPZ Challenge (NF54) and PfSPZ
Challenge (7G8) for repeat CHMI.
A total of 30 adult, healthy, malaria naïve volunteers will receive three injections by
Direct Venous Inoculation (DVI) of either placebo (n = 10), 51,200 PfSPZ Challenge (NF54) (n
= 10), or 150,000 PfSPZ Challenge (NF54) (n = 10) under chemoprophylaxis with A/P at 4 week
intervals. The placebo will be normal saline (0.9% NaCl).
Ten weeks after the last dose of PfSPZ Challenge (NF54) for immunization, volunteers will
undergo first CHMI and followed until asexual blood stage parasitemia, detected by
quantitative real time PCR (qPCR) or thick blood smear microscopy. If parasitemic, they will
be treated with A/P (used in this case as a standard treatment regimen). In the event of no
parasitemia, volunteers will be followed until Day 28 post-CHMI and will not receive A/P.
Sixteen to forty-four weeks after the last immunization, a second CHMI will be administered
to assess longevity and cross-strain protection. All volunteers will be followed up to 28
days post-inoculation. Those developing parasitemia will be treated with A/P.
Volunteers of Group A will have CHMI with PfSPZ Challenge (NF54) followed by PfSPZ Challenge
(7G8). Volunteers of Group B will have CHMI with PfSPZ Challenge (NF54) or PfSPZ Challenge
(7G8) followed by PfSPZ Challenge (7G8). In the case that protective efficacy in Group A is
≥75% CHMI sequence will be 7G8-7G8. In the case that protective efficacy against homologous
Challenge in Group A is <75%, volunteers will receive the same sequence as in Group A
(NF54-7G8).
Phase:
Phase 1
Details
Lead Sponsor:
University Hospital Tuebingen
Collaborator:
Sanaria Inc.
Treatments:
Atovaquone Atovaquone, proguanil drug combination Proguanil Vaccines