Tafenoquine feasibility study in Vietnam

ISRCTN	ISRCTN15552312
DOI	https://doi.org/10.1186/ISRCTN15552312
Clinical Trials Information System (CTIS)	Nil known
Protocol serial number	MMV_TQ_Vietnam_2201
Sponsor	PATH
Funders	Bill and Melinda Gates Foundation, Unitaid

Submission date: 27/11/2023
Registration date: 07/12/2023
Last edited: 25/03/2026

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Infections and Infestations

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English summary of protocol

Background and study aims
Malaria is a big health issue in many countries around the world. Among the six types of parasites causing malaria in humans, Plasmodium vivax (P. vivax) is the second most common after P. falciparum, and it's found in the widest range of places. According to the World Health Organization (WHO), there were about 6.4 million cases of P. vivax malaria globally in 2019. P. vivax infection is marked by the persistence of dormant parasites (called liver-stage hypnozoites), leading to recurring malaria episodes months or even years after the first infection.

This study is looking into the practicality of a new way of treating P. vivax malaria. The main goal is to see if this new approach works well in practice, and the secondary goals are to check if it's safe, acceptable, and cost-effective. The new treatment plan includes using a quick test for G6PD and a radical cure treatment with tafenoquine (TQ). The study will roll out this updated plan in health facilities across six districts and also test it in different strategies for finding cases: actively looking for cases, reacting when cases are found, and just waiting for people to come in for treatment. The study will compare how well G6PD testing and TQ work in these different strategies and how much they cost. The evidence collected will be used to inform future decisions. The study will use a mix of methods, including looking at the numbers from case management, talking to people through interviews and group discussions, and comparing costs between the different case-finding approaches.

To make sure the new approach is safe, the study will keep track of patients and deal with any cases of serious side effects. The people involved in the study include those with P. vivax malaria, the healthcare workers treating them, and the staff in charge of malaria programs who actively look for cases.

Who can participate?
Patient with a confirmed P. vivax infection, aged 6 months or older.

What does the study involve?
Patients will be routinely treated according to the national treatment guidelines.

What are the possible benefits and risks of participating?
None

Where is the study run from?
PATH (Switzerland)

When is the study starting and how long is it expected to run for?
June 2023 to November 2025

Who is funding the study?
Bill and Melinda Gates Foundation (USA)
Unitaid (Switzerland)

Who is the main contact?
Dr Thang Tran, thangtran@path.org
Prof Phuc Bui, phucnimpe@gmail.com

Contact information

Prof Phuc Bui
Public, Scientific, Principal investigator

34 Trung Van street, Nam Tu Liem district
Ha Noi
100000
Viet Nam

Phone	+84 983522874
Email	phucnimpe@gmail.com

Dr Thang Tran
Scientific

11th floor, 49 Hai Ba Trung Steet, Tran Hung Dao Ward, Hoan Kiem District
Ha Noi
100000
Viet Nam

Phone	+84 913301883
Email	thangtran@path.org

Study information

Primary study design	Observational
Study design	Prospective longitudinal operational study with mixed-methods approach including qualitative component quantitative component and costing component
Secondary study design	Longitudinal study
Scientific title	A mixed-method operational research study on the use of tafenoquine and G6PD testing for radical cure of Plasmodium vivax malaria in passive and active case detection in Vietnam
Study objectives	The use of tafenoquine after semi-quantitative G6PD testing for radical cure of Plasmodium vivax malaria is operationally feasible based on the revised algorithm in Vietnam, a country approaching elimination.
Ethics approval(s)	1. Approved 25/10/2023, Ethics Review Committee of National Institute of Malariology, Parasitology and Entomology (NIMPE) (34 Trung Van street, Nam Tu Liem district, Ha Noi, 100000, Viet Nam; +84 912216817; thieunq@gmail.com), ref: 407/QD-VSR 2. Approved 13/03/2024, Ethics Review Committee of World Health Organization (Avenue Appia 20 1211 Geneva Switzerland, Geneva, 1201, Switzerland; +41 22 791 21 1; evansr@unitaid.who.int), ref: ERC.0003965
Health condition(s) or problem(s) studied	Malaria plasmodium vivax
Intervention	Patients will be routinely treated according to the national treatment guidelines in which tafenoquine has been included, we only obtain the informed consent to collect data for assessment of correct indication.
Intervention type	Mixed
Primary outcome measure(s)	Measured using patient records at the end of the study: 1. Proportion of P. vivax infected individuals that are correctly treated with TQ based on the revised algorithm as an aggregate and within each of three case finding strategies. 2. Proportion of P. vivax and mixed P. vivax infected individuals that are correctly treated with PQ based on the revised algorithm as an aggregate and within each of three case finding strategies.
Key secondary outcome measure(s)	Measured using patient records at the end of the study: 1. Proportion of non-eligible patients that receive Radical Cure (TQ&PQ) treatment 2. Proportion of patients experiencing acute hemolytic anemia (AHA) during the patient follow-up period 3. Health care provider knowledge and skills regarding G6PD testing and radical cure treatment over time as determined by a competency assessment 4. Patients, health care provider and supervisors’ perceptions of and experience with the new RC tools, specifically TQ, as reported in interviews and focus group discussions 5. Total monetary cost of including G6PD testing and single dose cure compared across case finding strategies 6. Per patient monetary cost of including G6PD testing and single dose cure compared across case finding strategies. 7. Number of recurrences of P.vivax infection reported by study participants during study duration, in total and stratified by treatment type. 8. The number of study participants who present again to the facility or are identified through active case detection methods with a recurrence of P.vivax infection during study duration in total and stratified by treatment type. 9. Number of P. vivax patients reporting moderate, severe, and serious adverse events after TQ and PQ administration during the study conduct. 10. Frequency and severity of each moderate, severe, and serious adverse event reported after TQ and PQ administration during the study conduct.
Completion date	30/11/2025

Eligibility

Participant type(s)	Carer, Health professional, Patient
Age group	Mixed
Lower age limit	6 Months
Upper age limit	100 Years
Sex	All
Target sample size at registration	150
Total final enrolment	21
Key inclusion criteria	1. Patient with a confirmed P. vivax infection. 2. Patients providing informed consent or assent
Key exclusion criteria	1. Unwilling to provide informed consent 2. Showing signs of severe infection (patients)
Date of first enrolment	23/08/2025
Date of final enrolment	31/10/2025

Locations

Countries of recruitment

Viet Nam

Study participating centre

National Institute of Malariology, Parasitology and Entomology (NIMPE)

34 Trung Van street, Nam Tu Liem district
Ha Noi
100000
Viet Nam

Results and Publications

Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Data sharing statement to be made available at a later date
IPD sharing plan

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Basic results			25/03/2026	No	No
Dataset	.csv file		25/03/2026	No	No
Other files	Informed consent form version 4.0	10/04/2025	23/03/2026	No	No
Plain English results			25/03/2026	No	Yes
Protocol file	version 4.0	10/04/2025	23/03/2026	No	No
Statistical Analysis Plan	version 1.0	09/12/2025	23/03/2026	No	No

Additional files

ISRCTN15552312_PROTOCOL_V4.0_10 Apr2025.pdf: Protocol file
ISRCTN15552312_ICF_V4.0_10Apr2025.pdf: Informed consent form
ISRCTN15552312_SAP_09Dec2025.pdf: Statistical Analysis Plan
ISRCTN15552312 Basic Results Summary.pdf: Basic results
ISRCTN15552312 Plain English Summary of Results.pdf: Plain English results
ISRCTN15552312 PAVEVietnamFSPatient_DATA_LABELS_2025-12-03.csv: .csv file

Editorial Notes

25/03/2026: The following changes were made to the study record:
1. The basic results have been uploaded as an additional file.
2. The plain English results have been uploaded as an additional file.
3. A dataset was uploaded as an additional file.
23/03/2026: The following changes were made to the study record:
1. Protocol, statistical analysis plan and informed consent form added.
2. The date of first enrolment was changed from 15/04/2025 to 23/08/2025.
3. The date of final enrolment was changed from 30/11/2025 to 31/10/2025.
4. The completion date was changed from 31/12/2025 to 30/11/2025.
5. Final enrolment number added.
05/03/2025: The following changes were made to the study record:
1. The recruitment start date was changed from 01/03/2025 to 15/04/2025.
2. The recruitment end date was changed from 30/09/2025 to 30/11/2025.
27/01/2025: The recruitment start date was changed from 15/01/2025 to 01/03/2025.
06/11/2024: The following changes were made:
1. The overall study end date was changed from 30/09/2025 to 31/12/2025.
2. The recruitment start date was changed from 15/11/2024 to 15/01/2025.
06/08/2024: The recruitment start date was changed from 15/08/2024 to 15/11/2024.
10/05/2024: The following changes have been made:
1. Ethics Review Committee of World Health Organization approval date added.
2. Public title was changed from "Tafenoquine for malaria feasibility study in Vietnam" to "Tafenoquine feasibility study in Vietnam".
3. The overall study end date was changed from 30/06/2025 to 30/09/2025.
4. The recruitment start date was changed from 15/05/2024 to 15/08/2024.
5. The recruitment end date was changed from 30/06/2024 to 30/09/2025.
06/12/2023: Trial's existence confirmed by Ethics Review Committee of National Institute of Malariology, Parasitology and Entomology (NIMPE).