Evaluating Levamisole for Treating Loiasis Infections

Randomized, Double-blind Trial Evaluating the Safety and Efficacy of a 3- or 5- Day Course of Levamisole 2.5 mg/kg in Subjects With Loa Loa Microfilaremia

Phase2; Phase3 Interventional Programme National de Lutte contre l'Onchocercose, Republic of the Congo · NCT06252961

This study tests if a medication called levamisole can help people with loiasis infections feel better by reducing the number of parasites in their blood over a few days.

Quick facts

PhasePhase2; Phase3
Study typeInterventional
Enrollment99 (estimated)
Ages18 Years to 65 Years
SexAll
SponsorProgramme National de Lutte contre l'Onchocercose, Republic of the Congo Government
Locations2 sites (Sibiti, Komono and 1 other locations)
Trial IDNCT06252961 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to assess the safety and efficacy of levamisole administered over 3 and 5 days for managing loiasis microfilaremia in infected individuals. The study focuses on patients carrying L. loa microfilaremia, a condition prevalent in Central Africa, and seeks to determine if longer treatment regimens can effectively reduce microfilarial density while maintaining an acceptable safety profile. Participants will receive either levamisole or a placebo, and their health will be monitored throughout the trial to evaluate outcomes.

Who should consider this trial

Good fit: Ideal candidates are healthy adults aged 18 to 65 who are carriers of L. loa microfilaremia and meet specific weight and health criteria.

Not a fit: Patients with acute or chronic infections, recent vaccinations, or those on certain medications may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could provide a safer alternative for managing loiasis and contribute to the elimination of onchocerciasis in co-endemic regions.

How similar studies have performed: Previous studies have shown the safety of single doses of levamisole, but this approach of longer treatment regimens is novel and has not been extensively tested.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Consent informed, written, signed and dated
* Women or men aged 18 to 65 years inclusive
* Carrier of L. loa microfilaremia
* Body weight ≥ 40 kg in women and ≥ 45 kg in men; and less than 90 kg
* In good health, as determined by medical questionnaire and general clinical examination
* Absence of acute or chronic infection :

Exclusion criteria

* Participation in any study other than a purely observational study, within the 4 weeks preceding this study (determined by the theoretical date of the first administration of levamisole or placebo)
* Any vaccination within 4 weeks previous to this study
* Infection requiring treatment in the 10 days previous to this study, as determined by the anamnesis during the medical interview (e.g. pulmonary infection , digestive or skin infection; with or without antibiotic treatment)
* Treatment with clozapine, phenothiazines, sulfasalazine, carbamazepine, synthetic antithyroid drugs, ticlopidine, cimetidine, and gold salts: whether it was long-term treatment, or treatment given as a single dose 10 days before the start of treatment for the clinical trial (precaution with regard to the risk of agranulocytosis of immuno-allergic or toxic origin)
* Known immunosuppressive pathology (by self-report)
* Past or present history of neurological (including epilepsy) or neuropsychiatric disease
* History of agranulocytosis
* Use of cocaine or other drugs of abuse in the 72 hours preceding administration of the trial treatment, as determined by history during the medical interview
* Any condition, in the opinion of the investigator, that exposes the subject to undue risk
* Known intolerance to levamisole
* Subjects who donated blood in the previous 8 weeks to study entry, with a standard volume (\> 500 mL)
* On clinical examination: symptoms, physical signs or laboratory findings suggestive of systemic disorders, including disorders, including renal, hepatic, cardiovascular, pulmonary, skin, immunodeficiency, psychiatric and other abnormalities that could interfere with the interpretation of trial results. The physician may then give a favorable or unfavorable opinion on the participant's inclusion.
* Ivermectin and/or levamisole taken in the last six months; and/or mebendazole or albendazole taken in the last month
* Pregnant and/or breast-feeding women

Where this trial is running

Sibiti, Komono and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions LoiasisOnchocerciasisFilariasisLevamisole
Last reviewed 2026-06-09 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.