Active clinical trials for "Malaria"

To investigate the comparative tolerability, metabolism and pharmacokinetics of individual enantiomers of PQ in healthy human volunteers. The specific aim is the comparative evaluation of the metabolism, pharmacokinetic behavior, and tolerability of the isomers of PQ (RPQ and SPQ and the racemic mixture RSPQ) in normal healthy human volunteers.

Sulfadoxine-pyrimethamine (SP) is currently recommended by the World Health Organization for use as intermittent preventive treatment against malaria in pregnancy (IPTp) in areas of moderate to high malaria transmission. However, in some locales malaria parasites have lost sensitivity to SP, compromising its protective effect. Dihydroartemisinin-piperaquine (DP) is a candidate replacement for SP. This trial is designed to confirm the cardio-safety of DP compared to SP amongst pregnant women in Tanzania.

This study will be conducted in a single centre, as an open single dose two parallel cohorts design with oral doses of MMV390048 administered in healthy male and female subjects between 18 to 55 years of age. Subjects will be screened within 28 days prior to entering the study. On Day 1 of the study each subject will receive one of the two MMV390048 prototype formulations, at a dose of 40 mg with 240 mL of water. Subjects will be discharged on Day 3 after 48h post-dose and they will attend the unit for follow-up visits on Days 5, 7, 10, 14, 19, 26 and 29.

The overall objective of this study is to evaluate the public health impact of targeted antimalarials subsidies through scale-up by determining the community-wide effects of targeting an antimalarial subsidy through a partnership between Community Health Volunteers (CHVs) and the private retail sector. The primary hypothesis to be tested is that offering a fixed-price voucher that reduces the cost for artemisinin combination therapy (ACT) purchase in the retail sector conditional on a positive malaria test (targeted subsidy) can improve uptake of testing for malaria and will increase the proportion of fevers tested for malaria before treatment. The study will be carried out in two sub-counties in Kenya with similar malaria burden but different access to health services; the investigators will use a cluster-randomized design to assign community units (CUs) in each sub-county to either an intervention or control arm. CHVs will be trained to use malaria rapid diagnostic tests (RDTs) to diagnose malaria in household members with documented or reported fever; households in intervention CUs will be informed of the intervention and encouraged to contact the CHV for any febrile illness in the home. There are minimal risks associated with receiving an RDT. Households with a positive RDT will be given a serialized voucher that will entitle the holder to purchase a quality assured ACT in the retail sector at a reduced, fixed price. The primary and secondary outcome measures will be compared at baseline and 12 months post-baseline through population-based surveying. The primary aim is to determine whether there is significant difference between the 2 study arms in the proportion of clients with fever who are tested prior to any treatment after adjusting for relevant covariates.

A randomized double-blind controlled trial will be carried out in which young, nulliparous (having never given birth) women will be randomly assigned to receive weekly supplementation with either iron and folic acid or folic acid alone. Women will be followed-up weekly up to 18 months. Women who become pregnant will be followed-up until delivery. Malaria risk in both groups will be compared by assessing the prevalence of peripheral parasitaemia at the first antenatal clinic visit for pregnant women and at the end of the first malaria transmission season for non-pregnant women. The incidence of clinical malaria will be assessed by active and passive case detection throughout the follow-up period.

Malaria is one of the major infectious diseases in the world with a tremendous impact on the quality of life, significantly contributing to the ongoing poverty in endemic countries. It causes 800.000 deaths per year, the majority of which are children under the age of five. The malaria parasite enters the human body through the skin, by the bite of an infected mosquito. Subsequently, it invades the liver and develops and multiplies inside the hepatocytes. After a week, the hepatocytes burst open and the parasites are released in the blood stream, causing the clinical phase of the disease. As a unique opportunity to study malaria immunology and efficacy of immunisation strategies, a protocol has been developed in the past to conduct controlled human malaria infections (CHMIs). CHMIs generally involve small groups of malaria-naïve volunteers infected via the bites of P. falciparum infected laboratory-reared Anopheline mosquitoes. Although potentially serious or even lethal, P. falciparum malaria can be radically cured at the earliest stages of blood infection when risks of complications are virtually absent. The investigators have shown previously that healthy human volunteers can be protected from a malaria mosquito (sporozoite) challenge by immunization with sporozoites (by mosquito bites) under chloroquine prophylaxis (CPS immunization). Interestingly, sterile protection in 100% of the human CPS immunized volunteers was achieved by a relatively miniscule dose, i.e. a total of 45 infectious mosquito bites, strikingly 20-fold more potent than the 1000 bites needed in a model using irradiated mosquitoes. One possible explanation for this efficient induction of protective immunity, is the immune modulating effect of chloroquine. The investigators aim to assess this possible immune modulating effect in CPS immunization by comparing immunization with P. falciparum sporozoites under chloroquine with immunization under mefloquine prophylaxis, which has the same antimalarial effect, but not the immune modulating effects known from chloroquine.

A clinical trial aimed to standardize a vivax sporozoite infection model in human volunteers was conducted at the Malaria Vaccine and Drug Development Center (MVDC) in collaboration with the Immunology Institute at Valle State University and the Fundación Clínica Valle del Lili (FCVL) in Cali, Colombia. The primary objective was to determine if naïve human volunteers could be safely and reproducibly infected by the bite of An. albimanus mosquitoes carrying P. vivax sporozoites in their salivary glands and a secondary objective consisted in determining the minimal number of infected mosquitoes required to infect all volunteers, with a reproducible pre-patent period. The trial was divided into two steps: Step A directed to obtain human blood infected with P.vivax parasite used to infect anopheles mosquitoes and Step B to produce P. vivax sporozoites in Anopheles mosquitoes to determine the dose response of naive human volunteers exposed to 3 +/- 1, 6 +/- 1 y 9 +/- 1 mosquitoes bites. A total of 15 samples of P. vivax infected donors were used to infect different batches of mosquitoes.

This is an open label, human pilot study to optimise controlled human malaria infection (CHMI) administered by Plasmodium falciparum sporozoites (PfSPZ. Volunteers will be inoculated with PfSPZ Challenge. The route of administration and dose will vary in order to identify the optimal regimen that achieves the greatest infection rate in volunteers with Plasmodium falciparum. All volunteers recruited will be healthy adults aged between 18 and 45 years. Safety and infectivity data will be collected for each of the regimens.

DDI study of Tafenoquine and Chloroquine

This study will be a single-center, phase I, randomized, open, in fed condition, parallel, single dose study to evaluate the pharmacokinetics and the safety, tolerability of Atovaquone/proguanil combination tablets and atovaquone suspension in Japanese healthy male subjects. Serial blood samples will be collected for the determination of the plasma concentration of atovaquone, proguanil and cycloguanil after dosing of atovaquone 1000mg/proguanil 400 mg and the plasma atovaquone concentration of atovaquone 750 and 1500 mg. Safety assessments will be performed for each treatment group. CYP2C19 contribute to proguanil metabolism. CYP2C19 genotype will be determined in atovaquone/proguanil dosing group.