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Clinical Trial Details — Status: Recruiting

Administrative data

NCT number NCT01662700
Other study ID # FTM1202
Secondary ID
Status Recruiting
Phase Phase 4
First received August 8, 2012
Last updated January 24, 2013
Start date October 2012
Est. completion date December 2014

Study information

Verified date January 2013
Source Mahidol University
Contact n/a
Is FDA regulated No
Health authority Thailand: Ethical Committee
Study type Interventional

Clinical Trial Summary

In Thailand, the proportion of P.vivax infection has now been increasing and is equal to Plasmodium falciparum since 1998. The incidence of P.vivax has recently been reported as 20 per 1000 population per year. Unlike Plasmodium falciparum, P.vivax infection rarely develops into complicated malaria and death is unusual. However, P.vivax has a dormant stage (the hypnozoite) that persists in the human liver and may cause relapse weeks, months, or even years later. Therefore, P.vivax infection is considered to have greater impact on morbidity than mortality, resulting in significant social and economic burden. Moreover, it is very difficult to control P.vivax transmission, because gametocytes appear almost simultaneously with schizonts.

Radical treatment of the infection, therefore, normally consists of a blood schizontocidal course of chloroquine and a course primaquine for the elimination of the hypnozoites as anti-relapse therapy. In Thailand, chloroquine and primaquine have remained the mainstay chemotherapeutics for the treatment of P.vivax for more than 60 years and resistance has not yet been reported . The relapse rates at day 28 are about 50% without primaquine therapy and about 20% with standard primaquine therapy. Relapse has not been observed among patients receiving high dose primaquine therapy (30 mg daily for 14 days).

Since January 2007, the evidence of reduced susceptibility of Plasmodium falciparum to artemisinins in Western Cambodia at Thai-Cambodia border was first presented and confirmed in a subsequent detailed pharmacokinetic-pharmacodynamic study. Nevertheless, a trend of gradual decline of in vitro sensitivity to chloroquine has been documented in some areas of the country, particularly Thai-Myanmar border. There has been no clinical-parasitological evidence of chloroquine resistant P.vivax in Thai-Cambodia border, Thailand.

The objectives of the present study are to assess in vivo efficacy of first line regimen of chloroquine given with primaquine, and in vitro susceptibility of P.vivax isolates in areas along Thai-Cambodia border, Thailand.


Description:

Plasmodium vivax affects 70-80 million cases of malaria worldwide annually, is the major cause of human malaria in parts of Pacific region and South America. In Thailand, the proportion of P.vivax infection has increased and it is now equal to Plasmodium falciparum since 1998. The incidence of P.vivax has recently been reported as 20 per 1000 population per year. Unlike Plasmodium falciparum, P.vivax infection rarely develops into complicated malaria and death is unusual. However, P.vivax has a dormant stage (the hypnozoite) that persists in the human liver and may cause relapse weeks, months, or even years later. Therefore, P.vivax infection is considered to have greater impact on morbidity than mortality, resulting in significant social and economic burden. Moreover, it is very difficult to control P.vivax transmission, because gametocytes appear almost simultaneously with schizonts.

Radical treatment of the infection, therefore, normally consists of a blood schizontocidal course of chloroquine and a course primaquine for the elimination of the hypnozoites as antirelapse therapy. However, chloroquine-resistant P.vivax (CRPv) has been emer-ging in different parts of the world. The first report of chloroquine resistant Plasmodium vivax was in 2 Australian soldiers returning from Papua New Guinea in Indonesia and is now spreading over Asia and the Pacific region. In Thailand, chloroquine and primaquine have remained the mainstay chemotherapeutics for the treatment of P.vivax for more than 60 years and resistance has not yet been reported. Occasional failure of the standard primaquine therapy (15 mg daily for 14 days) to prevent relapse has been observed. However, primaquine resistance has not been confirmed. In Thailand, the relapse rates at day 28 are about 50% without primaquine therapy, and about 20% with standard primaquine therapy. Relapse has not been observed among patients receiving high dose primaquine therapy (30 mg daily for 14 days).

A number of factors are reportedly associated with relapse, or the reappearance of P.vivax, including inadequate primaquine dosage, high parasitaemia at diagnosis, and short duration of symptoms prior to diagnosis, presence of gametocytes on admission, age, and gender. Because the radical cure of P.vivax hypnozoites requires 14 days of primaquine therapy, adherence to the drug regimen may greatly affect the prevention of relapse. Unfortunately, the effect of patient adherence on 14 day primaquine treatment, and its relation to preventing parasite reappearance, is not well-document.

Since January 2007, the evidence of reduced susceptibility of Plasmodium falciparum to artemisinins in Western Cambodia at Thai_Cambodia border was first presented and confirmed in a subsequent detailed pharmacokinetic-pharmacodynamic study. Nevertheless, a trend of gradual decline of in vitro sensitivity to chloroquine has been documented in some areas of the country, particularly Thai-Myanmar border. There has been no clinical-parasitological evidence of chloroquine resistant P.vivax in Thai-Cambodia border, Thailand.

The objectives of the present study are to assess in vivo efficacy of first line regimen of chloroquine given with primaquine, and in vitro susceptibility of P.vivax isolates in areas along Thai-Cambodia border, Thailand.


Recruitment information / eligibility

Status Recruiting
Enrollment 120
Est. completion date December 2014
Est. primary completion date December 2014
Accepts healthy volunteers No
Gender Both
Age group 18 Years to 65 Years
Eligibility Inclusion Criteria:

- Male or female, aged from 18 years to 65 years old who can come to the study hospital for follow up in case of re-infection

- Acute uncomplicated malaria with P.vivax infection, confirmed by positive blood smear with asexual forms of P. vivax with parasitaemia > 1,000 parasites/microliters

- Fever defined as temperature > 37.5 degree celsius or a history of fever within the last 24 hours

- Written informed consent

- Willingness and ability of the patients/guardians to comply with the study protocol for the duration of the study

- Communicate with Thai language

Exclusion Criteria:

- Mixed infection with other plasmodium species

- For females: pregnancy, breast feeding

- History of allergy or known contraindication to chloroquine, artesunate or primaquine

- Any criteria of severe / complicated malaria (WHO 2010)

- Presence of febrile condition caused by disease other than malaria.

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment


Related Conditions & MeSH terms


Intervention

Drug:
Artesunate

Chloroquine


Locations

Country Name City State
Thailand Kraburi Hospital Ranong
Thailand Khunhan Hospital Srisaket
Thailand Phusing Hospital Srisaket
Thailand Kap Choeng Hospital Surin

Sponsors (1)

Lead Sponsor Collaborator
Mahidol University

Country where clinical trial is conducted

Thailand, 

Outcome

Type Measure Description Time frame Safety issue
Primary Parasite Clearance Rate Parasite clearance rate as defined by the slope of the linear portion of the natural logarithm parasite clearance curve 7 days No
Primary Relapse rate of P. vivax Incidence of relapse in P.vivax infection 3 months No
Secondary Parasite clearance time Parasite clearance time assessed by microscopy 7 days No
Secondary Parasite density time Time of parasite count to fall to 50%, 90% and 99% of initial parasite density 7 days No
Secondary Fever clearance time Fever clearance time (i.e. the time taken for temperature to fall below 37 degrees celsius and remain there for at least 24 hrs) 7 days No
Secondary Proportion of patients with gametocytemia Proportion of patients with gametocytemia before, during and after treatment, assessed at admission, on day 3 stratified by presence of gametocytes at enrolment 7 days No
Secondary In vitro antimalarial drug susceptibility IC0, IC90, IC99 of Plasmodium vivax responses to antimalarial drugs ( ex vivo) 7 days No