The efficacy and safety of rituximab on ME/CFS symptoms after administration to patients with myalgic encephalomyelitis/chronic fatigue syndrome will be compared in an exploratory, placebo-controlled, double-blind fashion.
View on ClinicalTrials.gov ↗Last updated 07 October 2026 from ClinicalTrials.gov. Trial statuses are refreshed automatically; check the registry record for the latest status and contact details.
5 trials1 open to enrolment3 completed1 terminated
All interventional trials in our ClinicalTrials.gov extract that list Rituximab as an intervention, across ME/CFS (5). 1 is currently open to enrolment and 3 have completed. Read the OSMF evidence profile for Rituximab for literature, mechanism and dosing context.
Intervention names are normalised from the registry's own arm labels, so the same compound can appear under a brand name, a generic name or a combination; check the full agent index for related entries.
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Not medical advice. This page is an automatically compiled index of entries on ClinicalTrials.gov. Listing here is not an endorsement of any trial, sponsor or treatment, and trial status can change between our refreshes. Always confirm details on ClinicalTrials.gov and discuss participation with your own clinician.
Recruiting (1)
Completed (3)
The hypothesis is that a subgroup of patients with Chronic Fatigue Syndrome/ Myalgic Encephalopathy (CFS/ME) have a chronically activated immune system and may benefit from B-lymphocyte treatment using the monoclonal anti-CD20 antibody rituximab with induction and maintenance treatment.
View on ClinicalTrials.gov ↗Based on pilot patient observations,the investigators anticipate that chronic fatigue syndrome (CFS) patients may benefit from B-cell depletion therapy. The hypothesis is that at least a subset of CFS patients have an activated immune system involving B-lymphocytes, and that B-cell depletion may alleviate symptoms.
View on ClinicalTrials.gov ↗Based on pilot patient observations, and experience from the prior study KTS-1-2008, the investigators anticipate that chronic fatigue syndrome patients may benefit from B-cell depletion therapy using Rituximab induction with maintenance treatment.
View on ClinicalTrials.gov ↗Terminated (1)
Based on pilot patient observations, and experience from the prior study KTS-1-2008, the investigators anticipate that severely affected chronic fatigue syndrome patients may benefit from B-cell depletion therapy using Rituximab induction with maintenance treatment.
View on ClinicalTrials.gov ↗Frequently asked questions
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Open the trial's ClinicalTrials.gov record (the "View on ClinicalTrials.gov" button), read the Eligibility Criteria and Contacts and Locations sections, and contact the study team listed there. Trials only enrol at the sites shown in the record, so check whether a site is near you or whether the study is remote/decentralised. Your own clinician can help you judge whether a trial is a sensible option and may need to provide medical records.
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Early Phase 1 / Phase 1 studies test safety and dosing in a small group. Phase 2 studies look for a signal of benefit in a larger group and keep checking safety. Phase 3 studies are large confirmatory trials designed to show whether a treatment works well enough for approval. Phase 4 studies follow approved treatments after they reach the market. "Phase not applicable" is used by the registry for behavioural, device, rehabilitation and other non-drug interventions.
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No. OSMF does not sponsor, run or recruit for any trial on this page. We compile public registry entries from ClinicalTrials.gov so patients and clinicians can find them in one place. For questions about a specific study, contact the sponsor or study team listed on its ClinicalTrials.gov record.
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Open Source Medicine Foundation. Rituximab clinical trials for Long COVID, ME/CFS and post-viral illness (5 trials, updated October 2026). Research Tracker, 07 October 2026.
Underlying dataset (JSON, CC BY 4.0):
Open Source Medicine Foundation. Rituximab clinical trials for Long COVID, ME/CFS and post-viral illness (5 trials, updated October 2026). Research Tracker, 07 October 2026.
https://research.opensourcemed.info/trials/by-agent/rituximab.htmlUnderlying dataset (JSON, CC BY 4.0):
https://research.opensourcemed.info/data/clinical_trials/clinical_trials_current.json. Source records: ClinicalTrials.gov.Related: all agents · recruiting Long COVID trials · recruiting ME/CFS trials · open in trial finder.