Experimental Vaccine for Plasmodium Falciparum Malaria
Condition: Plasmodium Falciparum Malaria; Vaccines
MeSH terms: Malaria; Malaria, Falciparum
Study type: Interventional
Phase: Phase 1

Summary: 
      This study will evaluate the safety of two experimental malaria vaccines in healthy
      volunteers and examine their immune response to them. Safety will be assessed by comparing
      vaccine side effects in groups of volunteers who receive increasing doses of the same vaccine
      (dose-escalating study). Immune response will be evaluated by comparing the levels of
      antibody production with each dose. (Antibodies are infection-fighting proteins produced by
      the immune system.) The two vaccines in this study contain different types of a malaria
      protein called MSP1: one type is MSP142FVO and the other is MSP1423D7.

      Malaria parasites are spread from person to person by mosquitoes. There are four types of
      malaria parasites. The vaccine tested in this study is designed to work against Plasmodium
      falciparum, the parasite responsible for most deaths in children due to malaria in
      sub-Saharan Africa. The vaccine stimulates the body to produce antibodies that prevent P.
      falciparum from entering the person's red blood cells.

      Healthy normal volunteers between 18 and 50 years of age may be eligible for this 12-month
      study, conducted at Quintiles Phase 1 Services in Lenexa, Kansas. Candidates are screened
      with a medical history, physical examination, and blood and urine tests.

      Participants receive three doses of the vaccine-on the first day of the study (day 0), at 1
      month (day 28), and at 6 months (day 180) -through injection into an arm muscle. The first
      group of subjects receives 5 micrograms of vaccine, the second group receives 20 micrograms,
      and the third group receives 80 micrograms. All participants are observed in the clinic for
      30 minutes after each immunization for immediate reactions to the vaccine and keep a record
      of their temperature and of any reactions and side effects they experience for 6 days after
      the vaccination. At various intervals throughout the study, participants undergo a brief
      physical examination and blood tests. Women of childbearing potential have a urine pregnancy
      test on the day of each injection.
    

Detailed description: 
      The purpose of this Phase 1 clinical trial is to evaluate the safety and immunogenicity of
      two asexual blood stage vaccines for Plasmodium falciparum malaria, MSP1(42)-FVO/Alhydrogel
      and MSP1(42)-3D7/Alhydrogel, in healthy adult volunteers. Between 2-3 million deaths occur
      each year as a result of malaria. Most of these deaths are a result of P. falciparum malaria,
      in children under five years of age, in sub-Saharan Africa. A safe and effective vaccine that
      would reduce both morbidity and mortality secondary to P. falciparum infection would be a
      valuable resource in the fight against this disease. The merozoite surface protein 1 (MSP1)
      is the first protein to be identified on the surface of the blood stage parasite. A portion
      of MSP1 is carried into the newly invaded erythrocyte on the surface of the parasite.
      Clinical symptoms of malaria in humans are due to the asexual blood stage. Therefore, this
      vaccine was designed to protect an individual from illness due to the asexual stage of P.
      falciparum infection by inhibiting parasite invasion of erythrocytes. The MSP1(42)/Alhydrogel
      vaccines have been used in five preclinical animal trials and no clinically significant risks
      have been identified. The study will be conducted at Quintiles Phase I Services (Lenexa, KS).
      We will evaluate three dose levels of both the MSP1(42)-FVO/Alhydrogel and the
      MSP1(42)-3D7/Alhydrogel vaccines (5 micro g, 20 micro g, 80 micro g). Sixty healthy male and
      non-pregnant female volunteers ages 18 to 50 will be enrolled. Ten volunteers in each group
      will receive a 5 micro g, 20 micro g, or 80 mirco g dose of either MSP1(42)-FVO or
      MSP1(42)-3D7 vaccines by intramuscular injection in an open label study on months 0, 1, and
      6. The groups will be staggered such that adequate safety evaluation can be performed prior
      to dose escalation. The duration of the study is 12 months per volunteer. The primary
      objective of this trial is to determine the frequency and severity of vaccine-related adverse
      events for each dose. The secondary objective is to determine the dose that generates the
      highest serum antibody levels to homologous MSP1(42) antigen at Day 42.
    

Intervention name(s): MSP1(42)-FVO & MSP1(42)-3D7
Intervention type(s): Drug
Primary purpose: Treatment
Keywords: Human; Clinical Trial; Mosquito