Sanaria PfSPZ Challenge With Pyrimethamine or Chloroquine Chemoprophylaxis Vaccination (PfSPZ-CVac Approach): A Randomized Double Blind Placebo Controlled Phase I/II Trial to Determine Safety and Protective Efficacy Against Natural Plasmodium Falcipa...

Summary

Background:

Malaria remains a major global health problem. Malaria is spread by the bite of mosquitos. Africa is the region of the world where most people get malaria. Sanaria PfSPZ Challenge is a malaria vaccine. Researchers want to see if the vaccine combined with partner drugs can help protect against malaria.

Objective:

To test if injections with 3 monthly doses of Sanaria PfSPZ Challenge, combined with either pyrimethamine (PYR) or chloroquine as a partner drug, is safe, tolerable, and effective.

Eligibility:

Healthy people ages 18-50 years who live in Bancoumana, Mali, or nearby

Design:

Participants will be screened with the Malaria Comprehension Exam to check their understanding of the study. They will have a medical history. They will have a physical exam. They will have blood tests, urine tests, and heart tests.

Participants will join either the pilot study or the main study.

Participants will be assigned to groups. Depending on their group, they will get at least one injection of either a placebo or the vaccine. They may have up to 3 vaccines, 4 weeks apart. The injection will be into a vein with a needle.

Participants will also take pyrimethamine or chloroquine by mouth. They will also take standard doses of antimalarial drugs by mouth.

Participants will have blood tests throughout the study.

Participants may develop a rash or injection site reaction. If this happens, photos of the site may be taken.

Participants will be observed for infection for many days after the injections.

Conditions

• Malaria

Interventions

DRUG

Chloroquine Phosphate

Chloroquine phosphate is approved for suppressive treatment (prophylaxis) and for acute attacks of malaria due to P. vivax, P. malariae, P. ovale, and susceptible strains of Pf. Chloroquine is a blood-stage schizonticide, highly active against replicating forms of blood-stage drug- sensitive parasites. As such, it is routinely employed as first-line prophylaxis against development of patent parasitemia and clinical malaria in non-immune travelers to areas with chloroquine sensitive Pf. In the pilot, chloroquine administration will begin with a loading dose 2 days prior to PfSPZ Challenge and finishing with a maintenance dose 5 days after PfSPZ Challenge. In the main phase, chloroquine will be first administered as a loading dose 2 days prior to PfSPZ Challenge and continuing weekly using a maintenance dose for a total of 10 doses, finishing with a last dose 5 days after the third injection with PfSPZ Challenge.

BIOLOGICAL

PfSPZ Challenge

PfSPZ Challenge (NF54) acts as the immunogen in the PfSPZ-CVac approach to vaccinating against malaria. Participants will receive either one (in the pilot phase) or 3 (in the main phase) 400,000 or 300,000 aseptic, purified, cryopreserved, fully infectious PfSPZ injections by DVI (with concurrent administration of antimalarial drugs). Following immunization, participants in the main phase will be followed through the transmission season in order to assess vaccine efficacy.

DRUG

Pyrimethamine

Pyrimethamine has been FDA approved for acute treatment and chemoprophylaxis of malaria due to susceptible strains of plasmodia. Pyrimethamine has been shown to possess both liver and blood stage activity. In this study, we plan to use a higher dose of pyrimethamine, 75 mg orally for either one or two days each month. The pilot arms will receive either a total of 1 daily dose or 2 daily doses. The main arms will receive a total of 3 daily doses or a total of 6 doses.

DRUG

Coartem

Antimalarial (Coartem ) will be administered to all participants twice during the study, approximately 2 weeks prior to the first vaccination in order to clear pre-existing parasitemia that may interfere with immunity development. The second dose will be given approximately 2 weeks prior to the 3rd vaccination in order to clear any parasitemia infection that may have happened naturally during the vaccination period and prior to the follow up period.

DRUG

ibuprofen

Ibuprofen likewise is not a part of the investigational product/regimen, but will be provided to participants in the chloroquine arm (Arm 4) if required to mitigate typical symptoms of malaria infection such as headache, myalgia, fever and chills.

Sponsors & Collaborators

• National Institute of Allergy and Infectious Diseases (NIAID)

  lead NIH

Principal Investigators

• Patrick E Duffy, M.D. · National Institute of Allergy and Infectious Diseases (NIAID)

Study Design

Allocation

RANDOMIZED

Purpose

OTHER

Masking

DOUBLE

Model

SEQUENTIAL

Eligibility

Min Age

18 Years

Max Age

50 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2019-05-23

Primary Completion

2021-02-10

Completion

2021-02-10

FDA Drug

Yes

Countries

• Mali

Study Locations