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CompletedNCT02802813Lao PvUpdated Mar 2, 2022

P.Vivax Treatment Trial

A Phase 1/2 interventional study of Dihydroartemisinin-piperaquine (DP) + Primaquine (PQ) and Dihydroartemisinin-piperaquine (DP) + Primaquine (PQ) placebo in Plasmodium Vivax, sponsored by University of Oxford. Completed at 1 site in Lao People's Democratic Republic. Open to participants aged 10 Years and older. Per ClinicalTrials.gov, last updated 2022-03-02.

Sponsored by University of Oxford · Phase 1/2, Interventional, and Treatment

Phase
Phase 1/2
Study type
Interventional
Enrollment
41
Allocation
Randomized
Ages
10 Years and older
Sex
All
01

Study summary

This study aims to determine whether a 14 day course of 0.5 mg/kg/day primaquine can eliminate subclinical P. vivax infections detected by high volume ultra-sensitive PCR (uPCR).

Read the detailed description

This is a randomized, Single blind trial in G6PD normal participants with subclinical P. vivax infections in Laos. Participants with subclinical P. vivax infections and those meeting the enrolment criteria will be randomly assigned to one of two treatment arms:

  • Intervention: Dihydroartemisinin-piperaquine (DP) therapy 3 days dosing plus 14 days of supervised primaquine (7mg/kg total dose) administered once per day (0.5 mg/kg/day).
  • Control arm: Dihydroartemisinin-piperaquine (DP) 3 days dosing therapy plus 14 days identical primaquine placebo.

Participants found to be G6PD deficient (G6PDd) will be treated with primaquine 0.75mg/kg/week for 8 weeks according to WHO recommendations. Primaquine and placebo will be administered with food (biscuits), which has been shown to reduce gastrointestinal side effects. All doses of study drugs will be supervised. If participants cannot visit the study centre, or fail to attend during the 14 days of supervised therapy, team members will visit them in their homes, schools or work to ensure complete dosing.

Findings:

The study showed that a 14-day course of primaquine added to mass drug administration with dihydroartemisinin-piperaquine prevented recurrent asymptomatic P. vivax infections (doi: 10.1186/s12936-019-3091-5)

02

Conditions studied

  • Plasmodium Vivax

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Keywords

  • Single-blinded controlled trial
  • Primaquine
03

In context

Malaria

1,299 studies on the registry are indexed under Malaria; 86 are open to participants now.

This study's enrollment of 41 is below the median of 220 across 1,027 interventional studies indexed under Malaria.

Browse Malaria studies →

Lead sponsor

University of Oxford is the lead sponsor of 794 studies on the registry; 117 are open to participants now.

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

04

Who can participate

Ages eligible
10 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Participants with subclinical mono- or mixed P. vivax infections (uPCR) can be enrolled.
  • Able to participate as decided by the investigators, and willing to comply with the study requirements and follow-up.
  • A participant (or parent/guardian of children below age of consent) is willing and able to give written informed consent to participate in the trial.

Exclusion criteria

Exclusion Criteria:

  • Currently pregnant or breastfeeding (female of child-bearing age).
  • Inability to tolerate oral treatment.
  • Previous episode of haemolysis or severe haemoglobinuria following primaquine.
  • Known hypersensitivity or allergy to the study drugs.
  • Blood transfusion in last 90 days, since this can mask G6PD deficiency.
  • An acute malaria episode requiring treatment.
  • A febrile condition due to diseases other than malaria (e.g. measles, acute lower respiratory tract infection, severe diarrhoea with dehydration).
  • Anaemia (Haemoglobin (Hb) \< 9 g/dL
  • Presence of any condition which in the judgment of the investigator would place the participant at undue risk or interfere with the results of the study (e.g. serious underlying cardiac, renal or hepatic disease; severe malnutrition; HIV/AIDS; or severe febrile condition other than malaria); co-administration of other medication known to cause haemolysis or that could interfere with the assessment of antimalarial regimens.
  • Currently taking medication known to interfere significantly with the pharmacokinetics of primaquine and the schizontocidal study drugs
05

Study design

Phase
Phase 1 / Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Single (Participant)
Enrollment
41 participants (actual)

Study arms

  • Active comparator
    Intervention arm

    Dihydroartemisinin-piperaquine (DP) therapy plus 14 days of supervised primaquine (7mg/kg total dose) administered once per day (0.5 mg/kg).

    Drug: Dihydroartemisinin-piperaquine (DP) + Primaquine (PQ)

  • Placebo comparator
    Control arm

    Dihydroartemisinin-piperaquine therapy plus 14 days identical placebo not containing primaquine.

    Drug: Dihydroartemisinin-piperaquine (DP) + Primaquine (PQ) placebo

Interventions

  • DrugDihydroartemisinin-piperaquine (DP) + Primaquine (PQ)
  • DrugDihydroartemisinin-piperaquine (DP) + Primaquine (PQ) placebo
06

What researchers measure

Primary outcomes

  1. The incidence rate of P. vivax parasitaemia in G6PD-normal participants

    the incidence rate will be detected by uPCR

    Time frame: over 12 months

Secondary outcomes

  1. Time to P. vivax clearance

    Detected by uPCR

    Time frame: 12 months

  2. The frequency of recurrent vivax infections (clinical and sub-clinical)

    Time frame: 12 months

  3. The follow-up period required to detect a statistically significant difference in the frequency of recurrent subclinical P. vivax infections between treated and untreated participants

    measured by uPCR

    Time frame: 12 months

  4. Number of participants with treatment related Adverse event.

    Time frame: 28 days

  5. Number of participants with treatment related malaria episode

    Time frame: 12 months

  6. Number of doses taken per participants

    Time frame: 14 days

  7. Compare the percentage decrease in hemoglobin between those who receive primaquine and who those not receive primaquine

    Time frame: 12 months

  8. Number of G6PD genotypes in participants with G6PD deficiency

    Time frame: 12 months

  9. Number of P450 genotypes in participants with recurrent PV infection.

    Time frame: 12 months

07

Study locations

1 site
  • Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit
    Vientiane, Lao People's Democratic Republic
08

References and documents

Publications

  • Phommasone K, van Leth F, Imwong M, Henriques G, Pongvongsa T, Adhikari B, Peto TJ, Promnarate C, Dhorda M, Sirithiranont P, Mukaka M, Peerawaranun P, Day NPJ, Cobelens F, Dondorp AM, Newton PN, White NJ, von Seidlein L, Mayxay M. The use of ultrasensitive quantitative-PCR to assess the impact of primaquine on asymptomatic relapse of Plasmodium vivax infections: a randomized, controlled trial in Lao PDR. Malar J. 2020 Jan 3;19(1):4. doi: 10.1186/s12936-019-3091-5. Erratum In: Malar J. 2020 Jan 21;19(1):32. doi: 10.1186/s12936-020-3124-0. PubMed 31900172 ↗
  • von Seidlein L, Peerawaranun P, Mukaka M, Nosten FH, Nguyen TN, Hien TT, Tripura R, Peto TJ, Pongvongsa T, Phommasone K, Mayxay M, Imwong M, Watson J, Pukrittayakamee S, Day NPJ, Dondorp AM. The probability of a sequential Plasmodium vivax infection following asymptomatic Plasmodium falciparum and P. vivax infections in Myanmar, Vietnam, Cambodia, and Laos. Malar J. 2019 Dec 30;18(1):449. doi: 10.1186/s12936-019-3087-1. PubMed 31888643 ↗

Individual participant data

Plan to share: Yes

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Mar 2, 2022, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT02802813
Lead sponsor
University of Oxford
Collaborators
Mahidol Oxford Tropical Medicine Research Unit
Responsible party
Sponsor
First posted
Jun 16, 2016
Start date
Jun 14, 2016
Primary completion
Jun 15, 2018
Completion
Jun 15, 2018
Last update
Mar 2, 2022

Study contacts

Mayfong Mayxay, MD
principal investigator · Lao-Oxford-Mahosot Hospital Wellcome Trust Research Unit

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Aug 2017. You cannot join it, but the record below documents what was studied.

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