Active — Not RecruitingPhase 2

ARN-75039 Lassa Fever Treatment in West Africa

United States, Nigeria135 participantsStarted 2026-02-14

Plain-language summary

This multicenter, randomized, open-label Phase 2 clinical trial evaluates the safety, tolerability, and virologic efficacy of ARN-75039, a novel oral antiviral, for treating Lassa fever in hospitalized adults in West Africa. The study is conducted within the INTEGRATE platform and compares two oral dose regimens of ARN-75039 (100 mg BID and 50 mg BID) with intravenous ribavirin, the locally mandated standard of care. Approximately 135 participants with RT-PCR-confirmed Lassa virus infection will be enrolled and randomized 1:1:1 to receive ARN-75039 high dose, ARN-75039 low dose, or ribavirin for 10 days, followed by safety and efficacy follow-up through Day 28. The primary objectives are to assess safety and tolerability and to evaluate antiviral activity, as measured by the change in slope of Lassa virus RT-PCR cycle threshold (Ct) values from Day 1 to Day 10, in participants with low baseline viral load Ct values. Secondary objectives include additional virologic, pharmacokinetic, and clinical outcome assessments, including time to viral clearance, symptom resolution, organ failure, and mortality. ARN-75039 is a small-molecule viral entry inhibitor targeting the Lassa virus glycoprotein complex and has demonstrated potent antiviral activity and favorable safety and pharmacokinetic profiles in preclinical models and Phase 1 clinical studies. This study aims to inform dose selection and support further clinical development of ARN-75039 as a potential treatment for Lassa fever.

Who can participate

Age range

18 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: Participants must meet all of the following criteria to be eligible for enrollment: * Age ≥ 18 years * Hospitalized with clinical disease consistent with Lassa fever * Positive plasma Lassa virus RT-PCR at screening * Requires hospitalization for Lassa fever per local clinical guidelines * Able to provide written informed consent, or consent provided by a legally authorized representative. Exclusion Criteria: Participants will be excluded if they meet any of the following criteria: * Pregnant (confirmed by positive urine pregnancy test in women of childbearing potential) * Receipt of specific drug therapy for Lassa fever (e.g., ribavirin, direct antivirals, or host-directed therapies including corticosteroids) within 15 days before enrollment * Prior vaccination against Lassa fever * History of severe gastrointestinal disease * History of chronic generalized pruritus * History of severe chronic liver disease * History of severe cardiac disorder Sex and Reproductive Criteria * Women of childbearing potential must have a negative pregnancy test at screening * Breastfeeding is not permitted during the treatment period and early follow-up * Participants must agree to comply with protocol-defined contraception requirements

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Incidence of Treatment-Emergent Adverse Events (TEAEs) Grade ≥3

Timeframe: Day 1 through Day 28

Change in Viral Load Slope (RT-PCR Ct Values)

Timeframe: Day 1 to Day 10

Trial details

NCT IDNCT07419373

SponsorArisan Therapeutics, Inc.

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2027-06

View on ClinicalTrials.gov More Lassa Fever trials