A Phase 3 interventional study of Rikkunshi-to and Placebo in Dyspepsia and Other Specified Disorders of Function of Stomach and Postprandial Distress Syndrome, sponsored by Universitaire Ziekenhuizen KU Leuven. Recruiting at 1 site in Belgium. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-07-23.
Sponsored by Universitaire Ziekenhuizen KU Leuven · Phase 3, Interventional, and Treatment
Dyspepsia refers to chronic or recurrent upper gastrointestinal (GI) symptoms originating from the gastroduodenal region with a significant impact on patients' lives. Functional dyspepsia comprises the diagnostic categories of epigastric pain syndrome (EPS) with epigastric pain or burning and postprandial distress syndrome (PDS) with meal-related fullness or early satiation, which are unexplained after routine investigation including upper GI endoscopy 2. Despite the common occurrence of FD in up to 15% of the general population, the underlying pathophysiology remains unclear and no treatments of proven efficacy are available in Europe for this condition.
Our group has demonstrated increased duodenal mucosal permeability and low-grade inflammation in FD patients, correlating with meal-related symptoms. The causes of the barrier defect and immune activation are unknown but candidates include psychological stress, luminal food components, (bile) acid and microbiota. The symptoms most closely associated with increased eosinophil counts in the duodenum are early satiation and postprandial fullness, which are typical PDS symptoms, and which are also associated with impaired gastric accommodation to meal ingestion and delayed gastric emptying.
Previously the efficacy of the Kampo medicine Rikkunshito (TJ-43) has been shown in FD. The exact mode of action remains to be determined. Previous studies have provided mechanistic evidence that rikkunshito is able to improve gastric accommodation, improve food intake and enhance circulating levels of the orexigenic gut peptide ghrelin.
The aim of this study is to evaluate the efficacy of Rikkunshito in comparison to placebo in PDS patients recruited from primary care in Belgium, and to evaluate whether this is associated with changes in duodenal mucosal low-grade inflammation.
372 studies on the registry are indexed under Dyspepsia; 67 are open to participants now.
This study's planned enrollment of 100 is above the median of 89 across 302 interventional studies indexed under Dyspepsia.
Browse Dyspepsia studies →Universitaire Ziekenhuizen KU Leuven is the lead sponsor of 963 studies on the registry; 267 are open to participants now.
Of its 5 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.
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:
1. Participant has a history of diabetes mellitus type 1, type 2 (including therapy), eosinophilic esophagitis, coeliac disease or inflammatory bowel disease, major abdominal surgery (except for appendectomy, cholecystectomy or splenectomy).
2. Any disorder, which in the Investigator's opinion might jeopardise the participant's safety or compliance with the protocol 3. Any prior or concomitant treatment(s) that might jeopardise the participant's safety or that would compromise the integrity of the Trial 4. If applicable: Female who is pregnant, breast-feeding or intends to become pregnant or is of and not using an adequate, highly effective 5. Patients with predominant symtoms of gastro-oesophageal reflux disease (GERD) or irritable bowel syndrome (IBS) 6. Patients with any active somatic or psychiatric condition that may explain dyspeptic symptoms (stable dose of single antidepressant allowed for psychiatric indication, no limitation for other indications) or severe depression using PHQ-7 (score of 20-27) 7. Patients already on PPI therapy20 or using a PPI in the last 2 weeks prior to enrolment 8. Patients with active (including therapy) 9. Known , , or infection (including therapy) 10. Significant alcohol use (more than 10 units a week) 11. Known allergy to Rikkunshito or any of its ingredients 12. Patients with overweight (>26)
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.
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.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
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.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
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.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Rikkunshito (TJ-43) Route of administration: P.O.; dose: 2.5 grams 3 times per day. Needs to be dissolved in about 30 ml of lukewarm water 30 minutes prior to the meal and swallowed as a single dose over approximately one minute at most.
Drug: Rikkunshi-to
Placebo Route of administration: P.O.; dose: 2.5 grams 3 times per day Needs to be dissolved in about 30 ml of lukewarm water 30 minutes prior to the meal and swallowed as a single dose over approximately one minute at most.
Other: Placebo
Kampo medicine (Herbal). ikkunshito is composed of the following eight herbal medicines: extracts of Atractylodes lancea Rhizome, Ginseng, Pinellia tuber, Poria sclerotium, Jujube, Citrus unshiu Peel, Glycyrrhiza, and Ginger. Among these, the extracts of the Atractylodes lancea Rhizome, Ginseng, Poria sclerotium, Pinellia tuber, Citrus unshiu Peel, and Glycyrrhiza
inactive drug, The matching placebo contains Corn Starch (vehicle), Lactose Hydrate (vehicle), Dextrin (vehicle), Magnesium Stearate (lubricant), FD\&C Blue No.1 Aluminum Lake (coloring agent), FD\&C Yellow No.5 Aluminum Lake (coloring agent), and Red Ferric Oxide (coloring agent).
Percentage responders of Rikkunshito compared to placebo in FD
Number of patients clinically relevant difference of 0.7 for the PDS symptoms (average of 3 questions of LPDS diary) by comparing pretreatment baseline scores with the average score during the last 2 weeks on treatment (responder definition). And compared Rikkunshito versus placebo.
Time frame: 8 weeks
The effect of Rikkunshito versus placebo on duodenal mucosal integrity
mucosal permeability and electrical resistance measured by Ussing-Chambers in duodenal biopsies
Time frame: 8 weeks
The effect of Rikkunshito versus placebo on Immune activation
Assessment of immune cell counts (mast cells and eosinophils) in duodenal biopsies
Time frame: 8 weeks
The effect of Rikkunshito versus placebo on duodenal microbiome
Assessment of DNA of bacteria at the level of duodenal mucosa biopsies
Time frame: 8 weeks
percentage minimal clinical response of rikkunshito
Number of patients clinically relevant difference of 0.5 for the PDS symptoms (average of 3 questions of LPDS diary) by comparing pretreatment baseline scores with the average score during the last 2 weeks on treatment (minimal clinical relevant reseponse definition). And compared Rikkunshito versus placebo.
Time frame: 8 weeks
The effect of Rikkunshito versus placebo on PDS clinical symptoms
assessed with the LPDS daily diary
Time frame: 8 weeks
The effect of Rikkunshito versus placebo on gastrointestinal symptoms
assessed by PAGI-SYM questionnaire
Time frame: 8 weeks
The effect of Rikkunshito versus placebo on quality of life
Assessed with the PAGI-Qol questionnaire
Time frame: 8 weeks
The effect of Rikkunshito versus placebo on psychologic distress
Assessed by the PHQ questionnaire
Time frame: 8 weeks
The response to Rikkunshito in patients with normal versus those with delayed gastric emptying rate at baseline.
assessed with the C13 gastric emptying breath test
Time frame: 8 weeks
• The effect of Rikkunshito versus placebo at 8 weeks on gastric emptying rate in those with delayed emptying at baseline.
assessed with the C13 gastric emptying breath test
Time frame: 8 weeks
Started Oct 2024 (actual). Primary completion is estimated for Oct 2026, 24 months after the start.
Of 15 phase 3 interventional studies under Dyspepsia, half reached primary completion within 13 months of starting (the median), counting those still running; a quarter within 8 and three quarters within 33. This study's planned 24 months is above that.
How these figures are worked out, and which studies are left out of them.
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Studies of the drug tested here: Liu-jun-zi-tang
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