ClinicalTrials.gg
CompletedNCT03931473NNPUpdated Oct 18, 2024

Efficacy of Two Dual Active Ingredient Long Lasting Insecticidal Nets for Control of Malaria Transmitted by Pyrethroid Resistant Vectors in Benin

An interventional study of Bed nets in Malaria and Anemia, sponsored by London School of Hygiene and Tropical Medicine. Completed at 1 site in Benin. Open to participants aged 6 Months to 9 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2024-10-18.

Sponsored by London School of Hygiene and Tropical Medicine · Not applicable, Interventional, and Prevention

Phase
Not applicable
Study type
Interventional
Enrollment
1,800
Allocation
Randomized
Ages
6 Months to 9 Years
Sex
All
01

Study summary

The massive scale-up of Long Lasting Insecticidal Nets (LLIN) has led to a major reduction in malaria burden (up to 50%) in many sub-Saharan African countries. This progress is threatened by the wide scale selection of insecticide resistant malaria vectors. New types of LLIN combining a mixture of two insecticides have been developed to control resistant mosquitoes.

The efficacy of two bi-treated LLIN are compared to a standard LLIN in a three-arm, single blinded, cluster-randomized trial in Cove, Benin. The arms are; 1/ Royal Guard, a net combining pyriproxyfen (PPF), which is known to disrupt female reproduction and fertility of eggs, and the pyrethroid alpha-cypermethrin, 2/Interceptor G2, LLIN incorporating a mixture of two adulticides with different modes of action; chlorfenapyr and a pyrethroid (alpha-cypermethrin), and 3/ The control arm: Interceptor, a standard LLIN treated with alpha-cypermethrin.

The primary outcome of the trial will be malaria case incidence in children aged 6 months to 10 years.

Read the detailed description

Background: The massive scale-up of Long-Lasting Insecticidal Nets (LLIN) has led to a major reduction in malaria burden (up to 50%) in many sub-Saharan African (SSA) countries. This progress is threatened by the wide scale selection of insecticide resistant malaria vectors.

Study site: The study will be conducted in the districts of Cove, Zagnanado and Ouinhi, a collection of three districts found in the Zou department in Benin. This area consists of 100 villages with approximately 40,000 households and a population size of 191,000.

The aim of this research is to evaluate the efficacy of 2 novel dual active Ingredient (AI) LLINs in a community randomized controlled trial on epidemiology outcomes. The trial will take place over 2 years in an area where malaria vectors are resistant to pyrethroid insecticide in Benin, West Africa. Update- the trial is now continuing for a third year.

The primary objective is to assess the efficacy of next generation LLIN on malaria case incidence in children aged 6 months to 10 years, compared to standard LLINs. The secondary objectives are to evaluate the efficacy of the 2 bi-treated LLIN as compared to standard LLIN on a) malaria infection prevalence in children aged 6 months to 10 years; b) prevalence of moderate and severe anaemia in children under 5 years old and c) entomological inoculation rate (EIR) (as a proxy for malaria transmission). In addition, we will compare potential insecticide resistance selection, between the 3 trial arms and evaluate the impact of the new types of LLIN on other entomological outcomes (species composition, blood feeding, resting/feeding behaviour and sterility (oocyte [egg] development).

Study design: Three-arm superiority, single blinded, cluster-randomized trial with village as the unit of randomisation. The arms consist of; 1/ Royal Guard, a net combining pyriproxyfen (PPF), which is known to disrupt female reproduction and egg fertility, and the pyrethroid alpha-cypermethrin, 2/Interceptor G2, a mixture LLIN incorporating two adulticides with different modes of action; chlorfenapyr and a pyrethroid (alpha-cypermethrin), and 3/ The control arm: Standard LLIN Interceptor is an alpha-cypermethrin only LLIN.

The primary outcome of the trial will be incidence of malaria cases (confirmed by rapid diagnostic test (RDT)) in children aged 6 months to 10 years followed for 24 months. Update: the study is now continuing for a further year.

Secondary outcomes are cross-sectional community prevalence of malaria infection (confirmed by RDT) in the study population at 6- and 18-months post-intervention, prevalence of moderate and severe anaemia in children under 5 years old, entomological inoculation rates (EIR), vector density and insecticide resistance intensity. Update: there will also be a 30 month cross-sectional survey.

Sample size: To compare incidence of malaria cases between study arms, we will recruit a cohort of 25 children per cluster in 60 clusters for 24 months follow up to be able to detect a 30% relative reduction in malaria cases per child per year (rate ratio 0.7) between the intervention and the reference arms. The children will be visited twice a month during the transmission season (April to November) and once a month during the dry season. We will conduct malaria infection prevalence cross-sectional surveys, at 6 and 18 months after LLIN distribution. 40 households will be randomly selected from each of the 60 clusters (20 clusters per arm x 3 arms) and information on education, socio economic status, LLIN ownership and usage recorded during each survey. From these 40 households per cluster we will randomly select 70 individuals. The study will have 80% power to detect a relative 30% lower prevalence (prevalence ratio 0.70 in each intervention arm (Royal Guard or Interceptor G2) relative to standard LLIN. Entomological inoculation rate (EIR) will be measured bi-monthly for 2 years in 8 households per cluster in all the clusters. Update: Follow up for cohort children was suspended during the pandemic meaning the primary outcome only included 21 months of follow up- to counteract this, 30 children were selected in each cluster. The follow up is now continuing up to 36 months- post-distribution. Due to logistics, the entomological data collection took place in 4 houses in each cluster every 3 months.

Frequency and intensity resistance assay with An. gambiae, An. arabiensis and An.funestus will be performed using permethrin, alpha-cypermethrin, pyriproxyfen and chlorfenapyr in 6 clusters (2 clusters per arm). An. gambiae s.l. and An. funestus will be screened for mutations in insecticide target sites (Vgsc) and metabolic resistance following CYp6 genes a small group of P450s that are over expressed in insecticide resistant populations. Changes in frequency of these genes and target site mutation will be followed every year in the three arms.

02

Conditions studied

  • Malaria
  • Anemia

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Keywords

  • Long Lasting Insecticidal Net, Chlorfenapyr, Pyriproxyfen, Pyrethroid, Randomised Controlled Trial, Benin, Vector Control, Malaria
03

In context

Malaria

1,184 studies on the registry are indexed under Malaria; 79 are open to participants now.

This study's enrollment of 1,800 is above the median of 252 across 937 interventional studies indexed under Malaria.

Browse Malaria studies →

Lead sponsor

London School of Hygiene and Tropical Medicine is the lead sponsor of 298 studies on the registry; 15 are open to participants now.

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

04

Who can participate

Ages eligible
6 Months to 9 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Children aged 6 months to 9 years
  • Resident in study villages
  • Written, from guardians

Exclusion criteria

Exclusion Criteria:

  • Non-residents
Terms in these criteria, in plain language(1)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

05

Study design

Phase
Not applicable
Primary purpose
Prevention
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Triple (Participant, Care provider, Outcomes assessor)
Enrollment
1,800 participants (actual)

Study arms

  • Experimental
    Interceptor G2

    Chlorfenapyr/alpha-cypermethrin

    Other: Bed nets

  • Experimental
    Royal Guard

    Pyriproxyfen/alpha-cypermethrin

    Other: Bed nets

  • Active comparator
    Interceptor

    Alpha-cypermethrin

    Other: Bed nets

Interventions

  • OtherBed nets

    Next-generation bed nets combining insecticides with different modes of action or a standard pyrethroid bed net

06

What researchers measure

Primary outcomes

  1. Malaria Case Incidence

    Malaria case incidence in children aged 6 months to 10 years measured through bi-monthly/monthly visits

    Time frame: 2 years

Secondary outcomes

  1. Malaria Infection prevalence

    Malaria infection prevalence measured in cross-sectional surveys 6 months and 18 months post- distribution

    Time frame: 18 months

  2. Entomological Inoculation Rate

    EIR measured every quarter during entomological surveys

    Time frame: 2 years

07

Study locations

1 site
  • Manfred Accrombessi
    Cove, Benin
08

References and documents

Publications

  • Accrombessi M, Cook J, Ngufor C, Sovi A, Dangbenon E, Yovogan B, Akpovi H, Hounto A, Thickstun C, Padonou GG, Tokponnon F, Messenger LA, Kleinschmidt I, Rowland M, Akogbeto MC, Protopopoff N. Assessing the efficacy of two dual-active ingredients long-lasting insecticidal nets for the control of malaria transmitted by pyrethroid-resistant vectors in Benin: study protocol for a three-arm, single-blinded, parallel, cluster-randomized controlled trial. BMC Infect Dis. 2021 Feb 19;21(1):194. doi: 10.1186/s12879-021-05879-1. PubMed 33607958 ↗
  • Yovogan B, Sovi A, Padonou GG, Adoha CJ, Akinro B, Chitou S, Accrombessi M, Dangbenon E, Akpovi H, Messenger LA, Osse R, Hounto AO, Cook J, Kleinschmidt I, Ngufor C, Rowland M, Protopopoff N, Akogbeto MC. Pre-intervention characteristics of the mosquito species in Benin in preparation for a randomized controlled trial assessing the efficacy of dual active-ingredient long-lasting insecticidal nets for controlling insecticide-resistant malaria vectors. PLoS One. 2021 May 20;16(5):e0251742. doi: 10.1371/journal.pone.0251742. eCollection 2021. PubMed 34014982 ↗
  • Accrombessi M, Cook J, Dangbenon E, Yovogan B, Akpovi H, Sovi A, Adoha C, Assongba L, Sidick A, Akinro B, Osse R, Tokponnon F, Aikpon R, Ogouyemi-Hounto A, Padonou GG, Kleinschmidt I, Messenger LA, Rowland M, Ngufor C, Protopopoff N, Akogbeto MC. Efficacy of pyriproxyfen-pyrethroid long-lasting insecticidal nets (LLINs) and chlorfenapyr-pyrethroid LLINs compared with pyrethroid-only LLINs for malaria control in Benin: a cluster-randomised, superiority trial. Lancet. 2023 Feb 11;401(10375):435-446. doi: 10.1016/S0140-6736(22)02319-4. Epub 2023 Jan 24. PubMed 36706778 ↗
  • Sovi A, Yovogan B, Adoha CJ, Akinro B, Accrombessi M, Dangbenon E, Assongba L, Salako AS, Padonou GG, Messenger LA, Ngufor C, Cook J, Protopopoff N, Akogbeto MC. Efficacy of pyrethroid-pyriproxyfen and pyrethroid-chlorfenapyr nets on entomological indicators of malaria transmission: third year of a randomised controlled trial in Benin. Sci Rep. 2024 Jun 5;14(1):12958. doi: 10.1038/s41598-024-63883-2. PubMed 38839981 ↗
  • Ngufor C, Fagbohoun J, Fongnikin A, Ahoga J, Syme T, Ahogni I, Accrombessi M, Protopopoff N, Cook J, Dangbenon E, Sovi A, Baes M, Pigeon O, Todjinou D, Govoetchan R, Padonou GG, Akogbeto M. The attrition, physical and insecticidal durability of two dual active ingredient nets (Interceptor(R) G2 and Royal Guard(R)) in Benin, West Africa: results from a durability study embedded in a cluster randomised controlled trial. Parasit Vectors. 2024 Oct 7;17(1):420. doi: 10.1186/s13071-024-06504-1. PubMed 39375740 ↗
  • Accrombessi M, Cook J, Dangbenon E, Sovi A, Yovogan B, Assongba L, Adoha CJ, Akinro B, Affoukou C, Padonou GG, Kleinschmidt I, Messenger LA, Rowland M, Ngufor C, Akogbeto MC, Protopopoff N. Effectiveness of pyriproxyfen-pyrethroid and chlorfenapyr-pyrethroid long-lasting insecticidal nets (LLINs) compared with pyrethroid-only LLINs for malaria control in the third year post-distribution: a secondary analysis of a cluster-randomised controlled trial in Benin. Lancet Infect Dis. 2024 Jun;24(6):619-628. doi: 10.1016/S1473-3099(24)00002-1. Epub 2024 Feb 21. PubMed 38401551 ↗

Individual participant data

Plan to share: No

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Ran from Jun 2020 to primary completion in May 2023, 35 months.

Of 95 non-industry interventional studies with no phase under Malaria, half reached primary completion within 23 months of starting (the median), counting those still running; a quarter within 11 and three quarters within 35. This study's 35 months is above that.

Counting every sponsor, half of 101 studies reached it within 23 months; a quarter within 8 and three quarters within 33.

How these figures are worked out, and which studies are left out of them.

Registered
Apr 25, 2019
First posted
Apr 30, 2019
StartActual
Jun 1, 2020
Primary completionActual
May 1, 2023
CompletionActual
May 1, 2023
Last update
Oct 18, 2024
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Oct 18, 2024, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT03931473
Collaborators
Centre de Recherche Entomologique de Cotonou, UNITAID, Innovative Vector Control Consortium, Global Fund
Responsible party
Sponsor
First posted
Apr 30, 2019
Start date
Jun 1, 2020
Primary completion
May 1, 2023
Completion
May 1, 2023
Last update
Oct 18, 2024

Study contacts

Martin C Akogbéto, PhD
principal investigator · Centre de Recherche Entomologique de Cotonou
Natacha Protopopoff, PhD
principal investigator · London School of Hygiene and Tropical Medicine

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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