A Phase 2 interventional study of Rituximab(Genetical Recombination) and Placebo in Myalgia Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), sponsored by National Center of Neurology and Psychiatry, Japan. Recruiting at 1 site in Japan. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-11-12.
Sponsored by National Center of Neurology and Psychiatry, Japan · Phase 2, Interventional, and Treatment
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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. In the subsequent secondary evaluation period, subjects who received rituximab in the primary evaluation period will receive placebo, and the timing and duration of rituximab's effect will be explored throughout the entire evaluation period. Subjects who received placebo during the primary evaluation period will receive rituximab during the secondary evaluation period to explore changes in endpoints before and after switching from placebo to rituximab in the same subjects.
The efficacy and safety of rituximab (genetical recombination), a CD20 antibody, 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. In the subsequent secondary evaluation period, subjects who received rituximab in the primary evaluation period will receive placebo, and the timing and duration of rituximab's effect will be explored throughout the entire evaluation period. Subjects who received placebo during the primary evaluation period will receive rituximab during the secondary evaluation period to explore changes in endpoints before and after switching from placebo to rituximab in the same subjects.
264 studies on the registry are indexed under Fatigue Syndrome, Chronic; 62 are open to participants now.
This study's planned enrollment of 30 is below the median of 60 across 178 interventional studies indexed under Fatigue Syndrome, Chronic.
Browse Fatigue Syndrome, Chronic studies →National Center of Neurology and Psychiatry, Japan is the lead sponsor of 9 studies on the registry; 2 are open to participants now.
Counted across the registry records on this site, refreshed daily.
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.
Exclusion Criteria:
Patients who test positive for at least one of surface (HBs) antigen, HBs antibody, Hepatitis B core (HBc) antibody, or virus (HCV) antibody.
However, patients who meet the following conditions (1) and (2) may be registered.
(i) Patients who are positive for HBs or HBc antibodies and whose HBV-DNA quantification is confirmed to be negative (less than detection sensitivity) and for whom appropriate monitoring, etc. can be conducted in accordance with the Guidelines for Hepatitis B Treatment edited by the Japan Society of Hepatology.
(ii) For patients with positive HCV antibody, when HCV-RNA quantification is negative (less than detection sensitivity)
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.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Absolute neutrophil count (ANC)
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Drug: Rituximab(Genetical Recombination)
Drug: Placebo
Subjects will be assigned to the rituximab pre-treatment group or placebo pre-treatment group and will receive the study drug (rituximab actual or rituximab placebo) intravenously four times at weekly intervals during the first three weeks of the primary and secondary evaluation periods.
Subjects will be assigned to the rituximab pre-treatment group or placebo pre-treatment group and will receive the study drug (rituximab actual or rituximab placebo) intravenously four times at weekly intervals during the first three weeks of the primary and secondary evaluation periods.
Improvement rate
Percentage of cases in which the severity score of ME/CFS based on PS by the MHLW research group improved by 1 or more compared to that before the start of study drug administration (week 0)
Time frame: From Baseline to the end of treatment at 24 weeks
Percentage of patients whose MHLW-PS-based ME/CFS severity score improved by 1 or more at each evaluation point (improvement rate) compared to that before the start of treatment with the investigational drug (week 0).
Time frame: At 4-week intervals from Baseline up to Week 48
The amount of change in the severity score of ME/CFS based on PS by the MHLW Research Group at each assessment point from that before the start of treatment with the investigational drug (week 0)
Time frame: At 4-week intervals from Baseline up to Week 48
Proportion of awake time spent in supine position (%),Proportion of awake time spent in sitting position (%)
Changes in proportions will be aggregated.
Time frame: At 4-week intervals from Baseline up to Week 48
Duration of standing and activity (hours)
Changes in time will be aggregated.
Time frame: At 4-week intervals from Baseline up to Week 48
Fatigue during rest and lying position
Patients will be asked to report the level of fatigue they feel even while lying down, and changes in their fatigue levels will be aggregated.
Time frame: At 4-week intervals from Baseline up to Week 48
Records on exertion and Post-Exertional Malaise (PEM)
Patients will be asked to describe the specific activities they perform and the exhaustion they experience afterward, and a summary table will be created.
Time frame: At 4-week intervals from Baseline up to Week 48
Assessment of fatigue during physical activity
Patients will be asked to report the level of fatigue they experience during physical activity in daily life, and changes in fatigue levels will be aggregated.
Time frame: At 4-week intervals from Baseline up to Week 48
Evaluation based on Fatigue Score
Patients will be asked to complete the Fatigue Score questionnaire, and changes in the score will be aggregated.
Time frame: At 2-week intervals from Baseline up to Week 48
SF-36
Changes in scores obtained from the SF-36 questionnaire will be assessed to evaluate patients' quality of life.
Time frame: At 12-week intervals from Baseline up to Week 48
COMPASS31
Changes in scores obtained from the COMPASS31 questionnaire will be assessed to evaluate patients' autonomic symptoms.
Time frame: At 12-week intervals from Baseline up to Week 48
Pittsburgh Sleep Quality Index (PSQI)
Changes in scores obtained from the PSQI questionnaire will be assessed to evaluate patients' sleep quality.
Time frame: At 12-week intervals from Baseline up to Week 48
Pain intensity
Pain intensity will be assessed using the Visual Analogue Scale (VAS)
Time frame: At 12-week intervals from Baseline up to Week 48
Grip strength
Patients' grip strength will be measured, and changes in the measurements will be aggregated.
Time frame: At 12-week intervals from Baseline up to Week 48
Analysis of the gut microbiota
samples collected from patients will be analyzed, and the composition of the gut microbiota will be aggregated.
Time frame: At 24-week intervals from Baseline up to Week 48
Brain imaging evaluation (Magnetic Resonance Imaging (MRI) of the head, Single Photon Emission Computed Tomography (SPECT) of cerebral blood flow)
Findings from imaging will be aggregated.
Time frame: At 24-week intervals from Baseline up to Week 48
Immune biomarker analysis (qPCR)
qPCR will be measured, and changes in their levels will be aggregated.
Time frame: At 24-week intervals from Baseline up to Week 48
Immune biomarker analysis (anti-autonomic receptor antibody analysis)
Quantify the level of anti-autonomic receptor antibodies will be measured, and changes in their levels will be aggregated.
Time frame: At 24-week intervals from Baseline up to Week 48
Immune biomarker analysis (immune cell subfractionation analysis)
The subsets of immune cells will be measured, and changes in the levels will be aggregated.
Time frame: At 24-week intervals from Baseline up to Week 48
Metabolome analysis
A detailed characterization of the patients' metabolome at baseline will be conducted.
Time frame: At Baseline
Adverse events
The number of adverse events will be aggregated.
Time frame: From Baseline up to Week 48
Vital signs (body temperature)
Summary statistics of vital signs will be calculated to monitor changes over time.
Time frame: Assessments will be conducted at baseline and at Weeks 1, 2, 3, 4, 8, 12, 24, 25, 26, 27, 28, 32, 36, and 48
Vital signs (blood pressure)
Summary statistics of vital signs will be calculated to monitor changes over time.
Time frame: Assessments will be conducted at baseline and at Weeks 1, 2, 3, 4, 8, 12, 24, 25, 26, 27, 28, 32, 36, and 48
Vital signs (pulse rate)
Summary statistics of vital signs will be calculated to monitor changes over time.
Time frame: Assessments will be conducted at baseline and at Weeks 1, 2, 3, 4, 8, 12, 24, 25, 26, 27, 28, 32, 36, and 48
Serum immunoglobulins (IgG)
Summary statistics of serum immunoglobulins will be calculated to monitor changes over time.
Time frame: At 4-week intervals from Baseline up to Week 48
Serum immunoglobulins (IgM)
Summary statistics of serum immunoglobulins will be calculated to monitor changes over time.
Time frame: At 4-week intervals from Baseline up to Week 48
Serum immunoglobulins (IgA)
Summary statistics of serum immunoglobulins will be calculated to monitor changes over time.
Time frame: At 4-week intervals from Baseline up to Week 48
Rituximab concentration of the blood plasma
Rituximab concentration of the blood plasma
Time frame: Assessments will be conducted at baseline and at Weeks 1, 2, 3, 4, 12, 24, 25, 26, 27, 28, 36, and 48
Blood drug concentration Anti-Drug Antibody (ADA)
Summary statistics of ADA will be calculated to monitor changes over time.
Time frame: Assessments will be conducted at baseline and at Weeks 4, 12, 24, 28, 36, and 48.
B cells (CD19/CD20 positive cells) and T cells (CD3/CD4/CD8 positive cells)
Summary statistics of B cells and T cells will be calculated to monitor changes over time.
Time frame: Assessments will be conducted at baseline and at Weeks 1, 12, 24, 25, 36, and 48.
Plan to share: No
No publications or documents are linked to this record.
Started Apr 2025 (actual). Primary completion is estimated for May 2028, 37 months after the start.
Since we started tracking on Sep 25, 2026, the dates moved once, on Nov 12, 2026: primary completion Sep 2026 → May 2028 and completion Oct 2027 → May 2028.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drug tested here: Rituximab
National Center of Neurology and Psychiatry, Japan