Active clinical trials for "Malaria, Vivax"

The investigators propose to leverage the unique infrastructures and expertise of National Centre for Parasitology Entomology and Malaria Control and the Pasteur Institute in Cambodia and combine modern fieldwork, including a mobile laboratory fully equipped for molecular biology and culture experiments, with state-of-the-art genomic analyses to investigate how Plasmodium vivax parasites respond to antimalarial drugs. The investigators will focus on resistance to CQ, the choice treatment for vivax malaria in most endemic countries, for which treatment failures have been reported in Cambodia. The study will address some of the key biological mechanisms limiting the efficiency of drug therapy in P. vivax, including the identification of genetic polymorphisms underlying drug resistance in Cambodian P. vivax. The findings will provide a first unbiased perspective on the mechanisms of drug resistance in P. vivax and have the strong potential to significantly improve malaria control in Southeast Asia.

This study will assess efficacy, safety , tolerability and PK in uncomplicated adult malaria patients with P. vivax or P. falciparum infection after 3 day dosing with KAF156 at 400 mg/day (Part 1) and single dosing with KAF156 at 800mg (Part 2)

This is a study of drug effectiveness for 2 treatments of vivax malaria, which is one of the two main types of malaria in Viet Nam. There are two important drugs used in Viet Nam for treating vivax malaria, Chloroquine and Artemisinin. Sometimes, when medicines are used for many years they become less effective at treating a disease, especially when they are not used at adequate doses according to national guidelines or when counterfeit drugs are available in the market. The purpose of this study is to check that Chloroquine and Artemisinin, are still effective for patients in Viet Nam. Participants in this study will be treated with either Dihydroartemisinin-Piperaquine (DHA-PPQ) or Chloroquine (CQ) for 3 days. Both drugs are recommended by the national guidelines to treat vivax malaria. The investigators would like to know if both of these treatments are equally effective so half of the patients in the study will be treated with DHA-PPQ and the other half will be treated with CQ. This way the investigators can compare the drugs to find out if one is better than the other. Participants will be followed for 3 days in hospital, then regularly by follow-up visits until the 63rd day. Tests will be done to determine the amount of drug and malaria parasites in the participant's body and how the blood cells react to the malaria. The parasite will be tested to determine what type it is and how it reacts to the treatment. The results of the study will be used to inform malaria treatment guidelines in Viet Nam.

This is a standard pharmacokinetic interaction study. Subjects will be randomized to be either group A or B. Group A. Subjects will have 3 hospitalizations to complete. Each hospitalization will be about 12-24 hours depends on each regimen. Subjects in A group who receive regimen 1 of primaquine (PQ) on the first admission (visit 2) will receive regimen 2 of primaquine and chloroquine combination (PQ and CQ) on second admission (visit 3) after 1 week wash out period and will finish with regimen 3 of Chloroquine (CQ) on the third admission (visit 4) after 8 weeks wash out period. Subjects in B group who receive regimen 1 of primaquine (PQ) will receive regimen 2 of chloroquine (CQ) on second admission (visit 3) after 1 week wash out period and regimen 3 of primaquine and chloroquine combination (PQ and CQ)on third admission(visit 4) with 8 week wash out period in between.

This study will assess efficacy, safety , tolerability and PK in uncomplicated adult malaria patients with P. vivax or P. falciparum infection after 3 day dosing with KAE609 at 30 mg/day

Plasmodium vivax represents a major health problem throughout the tropics. Outside Africa it accounts for over 50% of cases, affecting an estimated 70-80 million people per year. A substantial proportion of clinical cases are not caused by infective bites of Anopheles spp, but by activation of latent hypnozoites in the liver. These relapses may significantly impede development since each illness may result in 5-15 days of absence from work or school. Primaquine(PQ) is the only drug available that eliminates hypnozoites, though its use is beset by clinical problems; it may precipitate haemolytic anaemia in individuals deficient in the blood enzyme glucose 6 phosphate dehydrogenase (G6PD). Without affordable G6PD testing, primaquine use is precluded. Evidence suggests, however, that a course of 8 weekly doses may be a safe and effective alternative to the traditional 14 day course of the drug. The aim of the proposed study, therefore, is to test whether 8 weekly doses of primaquine is as effective as the 14 day course at preventing relapse malaria, without the risk of hemolysis in G6PD deficient individuals.

The cure rate of artemether/lumefantrine in the treatment of vivax malaria.

Feasibility of methylene blue-based combination therapy in the radical treatment of adult patients with Plasmodium vivax malaria in Ethiopia: a randomised controlled pilot trial Study rationale: Elimination has become the goal of malaria programmes in an increasing number of endemic countries and regions. Primaquine (PQ) is the only registered drug for radical cure of Plasmodium vivax malaria. Prolonged PQ-based combination therapy carries safety concerns and resistance to chloroquine (CQ) and PQ is emerging. Methylene blue (MB) has recently been shown to be safe and effective in the treatment of Plasmodium falciparum malaria in West Africa. As there is evidence for MB probably being effective against the hypnozoites of Plasmodium vivax, MB-based drug regimens could be an alternative to PQ-based combination therapy in Plasmodium vivax malaria. Study objectives: The main objective of this trial is to study the feasibility of MB-based combination therapy in patients with uncomplicated P. vivax malaria in an endemic area of Ethiopia.

This will be a single-arm observational cohort study. Malaria patients with Plasmodium vivax and meeting study inclusion criteria, who give consent to be enrolled in the study, will have their G6PD status measured by the CareStart™ G6DP rapid diagnostic test (G6PD RDT), and primaquine prescribed according to the result. According to the G6PD RDT result, primaquine will be prescribed at 0.25mg/kg/day for 14 days (normal patients) or 0.75mg/kg weekly for eight weeks (deficient patients). All will receive treatment with chloroquine to clear asexual stages of infection. Patients will be reviewed at day 2, day 7 and day 14. At these visits patients will undergo a brief clinical assessment and a small blood sample will be taken for repeat haemoglobin measurement and dried blood spot for carboxyprimaquine measurement (day 7 and day 14 only). In general, antimalarial treatment will be unsupervised to reflect field conditions. However a subset of 25 G6PD normal patients at a single site will have each day of their primaquine treatment administered and observed at the treatment centre. This is to determine a calibration curve for primaquine pharmacokinetic studies. Dried blood spots will be stored appropriately. Day zero samples will be genotyped in Bangkok (MORU, Dr. Mallika Imwong) after DNA extraction. PCR-RFLP will be used to detect the allele associated with the Mediterranean variant of G6PD deficiency. In addition DNA extracts will be sent for more systematic genetic testing for known G6PD variants through existing collaborations with the Wellcome Trust Sanger Institute. The day 7 and 14 dried blood spot samples will be analysed in the MORU pharmacology laboratory for primaquine and carboxyprimaquine concentrations, from which adherence to primaquine can be determined retrospectively, using the subset of 25 patients receiving directly observed therapy to calibrate the results. Funder: WellcomeTrust, Grant reference: 107548/Z/15/Z

This is an open label, Phase IIa, controlled human malaria infection (CHMI) study aimed to assess whether the new vivax malaria vaccines ChAd63 PvDBP and MVA PvDBP can protect against malaria infection. The participants will receive one or two doses of ChAd63 PvDBP followed by one dose of MVA PvDBP 8 weeks later. Approximately 4 weeks after the second vacccination, the volunteers will be challenged (deliberately infected) with malaria by intravenous injection blood-stage