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CompletedNCT02237586Updated Apr 23, 2015

Effect of Plasmodium Falciparum Exposure and Sickle Cell Trait on Infection Rates and Kinetics After IV Administration of PfSPZ Challenge

A Phase 1 interventional study of PfSPZ Challenge in Plasmodium Falciparum Malaria and Malaria, sponsored by Sanaria Inc.. Completed at 1 site in Gabon. Open to participants aged 18 Years to 30 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2015-04-23.

Sponsored by Sanaria Inc. · Phase 1, Interventional, and Basic science

Phase
Phase 1
Study type
Interventional
Enrollment
25
Allocation
Non-randomized
Ages
18 Years to 30 Years
Sex
All
01

Study summary

The study is designed to establish infectivity of Plasmodium falciparum sporozoites (PfSPZ) via intravenous (IV) administration in three groups with different malaria immunity-status:

  1. Adults with a history of lifelong malaria exposure without sickle cell trait (HbAA)
  2. Adults with a history of lifelong malaria exposure with sickle cell trait (HbAS)
  3. Adults without previous malaria episodes without sickle cell trait (HbAA)

Initially a dose of 3,200 PfSPZ will be given and the time until thick blood smear positivity after challenge will be assessed. If in any of the groups with a history of lifelong malaria exposure, 50% or less of individuals become thick blood smear positive during the 28 days post injection of PfSPZ Challenge, the dose will be increased 4-fold to 12,800 PfSPZ in this group.

Read the detailed description

LACHMI-001 is a partially-blinded, human pilot trial to study immunity against P. falciparum malaria in a controlled infection setting. The main objective is to characterise the role of sickle cell trait and naturally acquired immunity in development of malaria, defined by positive smear for P. falciparum and signs or symptoms associated with malaria. Three groups of volunteers will receive radical cure treatment and subsequently PfSPZ Challenge by IV administration. The groups are:

  1. Adults with naturally acquired immunity and HbAA (Group IA, n=10-20)
  2. Adults with naturally acquired immunity and HbAS (Group IS, n=10-20)
  3. Adults without previous exposure to malaria and HbAA (Group NI, n=5)

The initial challenge dose of 3,200 PfSPZ administered once intravenously leads to consistent infection in naïve adults (15/15 in prior studies) and thus should infect all volunteers in Group 3. However, volunteers with naturally acquired immunity or sickle cell trait might require a higher dose. Thus if 50% or less of volunteers become parasitemic in Groups IA or IS, 10 additional volunteers will be enrolled and challenged with 12,800 PfSPZ. All volunteers will be healthy adults aged 18 to 30 years. Safety and infectivity data will be collected for each of the regimens and dose-levels. Effective treatment is initiated immediately upon development of parasitemia together with the presence of symptoms associated with malaria.

Laboratory staff reading blood films and processing samples will be blinded to group allocation. Volunteers and clinical investigators will be blinded to group allocation among the IA and IS groups.

02

Conditions studied

  • Plasmodium Falciparum Malaria
  • Malaria

Keywords

  • Plasmodium falciparum malaria
  • Malaria
  • PfSPZ Challenge
  • Controlled Human Malaria Infection (CHMI)
  • Sickle Cell Trait
  • Sporozoites
03

In context

Malaria, Falciparum

455 studies on the registry are indexed under Malaria, Falciparum; 37 are open to participants now.

This study's enrollment of 25 is below the median of 126 across 376 interventional studies indexed under Malaria, Falciparum.

Browse Malaria, Falciparum studies →

Lead sponsor

Sanaria Inc. is the lead sponsor of 29 studies on the registry; 4 are open to participants now.

Of its 10 completed or terminated interventional studies of FDA-regulated products, 3 (30%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 30 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Healthy adult aged 18 to 30 years
  • Able and willing (in the investigator's opinion) to comply with all study requirements
  • Women only: must agree to practice continuous effective for the duration of the study (a method which results in a low failure rate; i.e. less than 1% per year)
  • Agreement to refrain from blood donation during the course of the study and after the end of their involvement in the study according to the local blood banking eligibility criteria
  • Written to undergo CHMI
  • Reachable (24/7) by mobile phone during the whole study period
  • Willingness to take two curative anti-malarial regimens
  • Agreement to stay overnight for observation during the period of intensive follow-up post-challenge if required
  • Answer all questions on the informed consent quiz correctly
  • A \< 35
  • A concentration ≥10 g/dl for women and ≥12 g/dl for men

Additional inclusion criteria for IA and IS group only:

  • History of long term residence (>10 years) in area known to have significant transmission of P. falciparum -

Exclusion criteria

Exclusion Criteria:

  • Use of anti-malarials within 30 days of study enrolment
  • Use of systemic antibiotics with known antimalarial activity within 30 days of study enrolment (e.g. trimethoprim-sulfamethoxazole, doxycycline, tetracycline, clindamycin, erythromycin, fluoroquinolones, or azithromycin)
  • Receipt of an product in the 30 days preceding enrolment, or planned receipt during the study period
  • Prior receipt of an investigational malaria vaccine
  • Immunization with more than 1 other vaccines within the past month.
  • infection
  • SS
  • Any confirmed or suspected or immunodeficient state, asplenia, recurrent, severe infections and chronic (more than 14 days) immunosuppressant medication within the past 6 months (inhaled and topical are allowed)
  • Use of immunoglobulins or blood products within 3 months prior to enrolment
  • Pregnancy, lactation or intention to become pregnant during the study
  • A history of allergic disease or reactions likely to be exacerbated by malaria
  • to the use of the anti-malarial medications: artemether/lumefantrine or atovaquone/proguanil.
  • History of cancer (except basal cell carcinoma of the skin and cervical carcinoma in situ)
  • History of serious psychiatric condition that may affect participation in the study
  • History of epileptic seizures
  • Any other serious chronic illness requiring hospital specialist supervision
  • Suspected or known current alcohol abuse as defined by an alcohol intake of greater than 60 g (men) or 40 g (women) per day
  • Suspected or known injecting drug abuse in the 5 years preceding enrolment
  • Seropositive for surface antigen (HBsAg)
  • Seropositive for virus (antibodies to HCV)
  • Falling in moderate risk or higher categories for fatal or non-fatal cardiovascular event within 5 years (>10%) determined by non-invasive criteria for cardiac risk
  • Abnormal on screening: pathologic Q wave and significant ST-T wave changes, left ventricular hypertrophy, non-sinus rhythm except isolated premature atrial contractions, right of left bundle branch block, advanced A-V heart block (secondary or tertiary)
  • A /QTc interval > 450 ms
  • Volunteers unable to be closely followed for social, geographic or psychological reasons
  • Any abnormal finding on biochemistry or haematology blood tests, urinalysis or clinical examination
  • Any other significant disease, disorder or finding which, in the opinion of the Investigator, may significantly increase the risk to the volunteer because of participation in the study, affect the ability of the volunteer to participate in the study or impair interpretation of the study data

Additional exclusion criteria for NI group only:

  • History of P. falciparum malaria
  • History of long term residence (>5 years) in area known to have significant transmission of P. falciparum
  • Presence of sickle cell trait
  • Known thalassemia or thalassemia trait

Exclusion Criterion on Day of Challenge or Day before Challenge

  • Acute disease, defined as moderate or severe illness with or without fever
  • Pregnancy
Terms in these criteria, in plain language(15)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

BMI (body mass index)

Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.

What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.

Hemoglobin (Hb)

The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

Immunosuppression

A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.

Read whether the line is about a condition or about medicines, and which medicines and doses it means.

Corticosteroids (steroids)

Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.

Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.

Contraindication

A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.

Line of therapy

A line of therapy is one course of treatment, which may combine several drugs. First-line is the first course given; second-line follows when that stops working or is not tolerated.

“Two prior lines” means two courses that count separately under the study’s rules — not simply two drugs. Ask the study team if you are unsure how yours are counted.

Hepatitis B tests

Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.

Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.

Hepatitis C tests

Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.

After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.

ECG (electrocardiogram)

A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.

QT and QTc

On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.

The study may name a correction formula and a limit in milliseconds, often around 450–480.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

05

Study design

Phase
Phase 1
Primary purpose
Basic science
Allocation
Non-randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
25 participants (actual)

Study arms

  • Experimental
    Group IA

    Adults with naturally acquired immunity and HbAA (Group IA, n=10) As any parasitemia other than PfSPZ will interfere with results, volunteers will undergo a treatment course against P. falciparum with a five-day course of 12-hourly 5 mg/kg clindamycin (corresponds to a 300 mg tablet of clindamycin base administered twice daily). This will be completed no less than three days prior to CHMI. The initial challenge dose of 3,200 PfSPZ Challenge will be administered once intravenously. If 50% or less of volunteers become parasitemic in Groups IA or IS, 10 additional volunteers will be enrolled and challenged with 12,800 PfSPZ. Effective treatment will be initiated immediately upon development of parasitemia together with the presence of symptoms associated with malaria.

    Biological: PfSPZ Challenge

  • Experimental
    Group IS

    Adults with naturally acquired immunity and HbAS (Group IS, n=10) As any parasitemia other than PfSPZ will interfere with results, volunteers will undergo a treatment course against P. falciparum with a five-day course of 12-hourly 5 mg/kg clindamycin (corresponds to a 300 mg tablet of clindamycin base administered twice daily). This will be completed no less than three days prior to CHMI. The initial challenge dose of 3,200 PfSPZ Challenge will be administered once intravenously. If 50% or less of volunteers become parasitemic in Groups IA or IS, 10 additional volunteers will be enrolled and challenged with 12,800 PfSPZ. Effective treatment will be initiated immediately upon development of parasitemia together with the presence of symptoms associated with malaria.

    Biological: PfSPZ Challenge

  • Experimental
    Group NI

    Adults without previous exposure to malaria and HbAA (Group NI, n=5) As any parasitemia other than PfSPZ will interfere with results, volunteers will undergo a treatment course against P. falciparum with a five-day course of 12-hourly 5 mg/kg clindamycin (corresponds to a 300 mg tablet of clindamycin base administered twice daily). This will be completed no less than three days prior to CHMI. The initial challenge dose of 3,200 PfSPZ Challenge administered once intravenously should lead to consistent infection in naïve adults (15/15 in prior studies) and thus should infect all volunteers in Group NI. Effective treatment will be initiated immediately upon development of parasitemia together with the presence of symptoms associated with malaria.

    Biological: PfSPZ Challenge

Interventions

  • BiologicalPfSPZ Challenge

    live, aseptic, cryopreserved P. falciparum sporozoites

06

What researchers measure

Primary outcomes

  1. Days from inoculation to start of malaria episode

    The time from parasite inoculation to first detection of malaria will be assessed by thick blood film microscopy and a clinical questionnaire. Malaria is defined as both parasitemia and clinical symptoms suggestive of malaria.

    Time frame: From day of injection until day 28

  2. Frequency, incidence and nature of adverse events

    The safety of PfSPZ Challenge administered IV and the resultant P. falciparum infection will be assessed by analysing actively and passively collected data from clinical review of volunteers and laboratory measurements.

    Time frame: From day of injection until day 28

Secondary outcomes

  1. Dynamics of P. falciparum parasite growth

    The dynamics of P. falciparum parasite growth following administration of PfSPZ Challenge is assessed by analyzing parasite multiplication rates using highly sensitive qPCR for P. falciparum DNA. Measurements will be used to model parasite kinetics and to estimate the number of infected liver cells.

    Time frame: From day 6 after injection until approximately day 28

Other outcomes

  1. Cellular and humoral immune responses against parasites

    Cellular and humoral immune responses against parasites will be assessed by individual and collective results of cytometry, enzyme-linked immunospot analysis (ELISpot), enzyme-linked immunosorbent assay (ELISA), immunofluorescence assay (IFA), inhibition of sporozoite invasion of hepatocytes assay (ISI), quantification of erythrophagocytosis, B-cell typing and isolation as well as protein microarray.

    Time frame: From screening until 6 months

  2. Stage specific expression patterns of parasite genes

    Stage specific expression patterns of parasite genes will be assessed by RNA quantification using reverse transcriptase PCR (rtPCR) and transcriptional profiling on microarray and sequencing platforms. Differences in miRNA expression between AA and AS erythrocytes will be determined and related to multiplication rates.

    Time frame: From screening until 6 months

07

Study locations

1 site
  • Centre de Recherches Médicales de Lambaréné
    Lambaréné, BP 118, Gabon
08

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Apr 23, 2015, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT02237586
Lead sponsor
Sanaria Inc.
Collaborators
Centre de Recherche Médicale de Lambaréné, Institute of Tropical Medicine, University of Tuebingen
Responsible party
Sponsor
First posted
Sep 11, 2014
Start date
Jul 2014
Primary completion
Sep 2014
Completion
Feb 2015
Last update
Apr 23, 2015

Study contacts

Bertrand Lell, MD
principal investigator · Centre de Recherche Médicale de Lambaréné

Oversight

Data monitoring committee
Yes
View the source record on ClinicalTrials.gov ↗

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This study is completed, as verified in Apr 2015. You cannot join it, but the record below documents what was studied.

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