A Phase 4 interventional study of botulinum toxin type A and Sodium Chloride 0.9% Inj in Retrograde Cricopharyngeus Dysfunction, sponsored by AZ Delta. Completed at 1 site in Belgium. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-10-29.
Sponsored by AZ Delta · Phase 4, Interventional, and Treatment
The aim of this study is to assess the effect of botulinum toxin injection into the upper esophageal sphincter in a double blind, placebo controlled study. Investigators want to assess the effect on symptoms short term (1-20 weeks after BT injection), and long term (48 weeks after BT injection).
This is a prospective double-blind randomized placebo-controlled study. Questionnaires assessing symptoms will be filled out on several occasions. At 20 weeks, a reassessment of symptoms will be done, without unblinding patients or investigator. Failures (to BT or placebo, defined as no clinical improvement or improvement less than 50%) will get the chance to receive a second procedure with active treatment (BT) in open label.
AZ Delta is the lead sponsor of 7 studies on the registry; 1 is open to participants now.
Counted across the registry records on this site, refreshed daily.
Participants eligible for inclusion in this Trial must meet all of the following criteria:
Inability to belch, which is bothersome enough to consider treatment*, present for at least 6 months prior to inclusion, and in fulfillment of both categories a and b below:,
Typical findings on high resolution impedance manometry with belch provocation test (10). These typical findings include: No relaxation upon gastroesophageal gas reflux, no air clearance via the UES but instead an increased air presence time include air entrapment and oscillations.
Participants eligible for this Trial must not meet any of the following criteria:
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.
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.
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.
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.
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.
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.
Drug: botulinum toxin type A
Drug: Sodium Chloride 0.9% Inj
Botulinum toxin type A 75U dissolved in 3mL physiological serum injection in the upper esophageal sphincter
Placebo: physiological serum 3mL injection in the upper esophageal sphincter
Response to Botox versus placebo, 12 weeks after treatment.
This questionnaire is a treatment effect measure specific for inability to belch, where the change in symptoms from baseline is assessed, on a scale from 0% to 100%. 100% means complete resolution of symptoms, 0% means no improvement.
Time frame: week 12
Response to botox versus placebo 48 weeks after treatment.
We will use the questionnaire of 'Difficulties with belching', and response is defined as at least a 50% improvement on question 6A 'To what extent have the symptoms of \'difficulty burping air\' been reduced after treatment?\'.
Time frame: 48 weeks
Safety: count of each type of (serious) adverse events in each group
Safety: assessed by the number and type of (serious) adverse events that occurred in each group by week 48
Time frame: 4 weeks
Safety on swallowing: with SSQ
assessed by the Sydney Swallow Questionnaire 1 week and 4 weeks after the procedure.
Time frame: 4 weeks
HRQOL
HRQOL using EQ-5D VAS score short-term (1, 4,12 weeks) and long-term (20 - 48 weeks after the procedure).
Time frame: 1 to 48 weeks
Patients experience and satisfaction of the treatment using overall treatment effect
Patients experience and satisfaction of the treatment based on OTE short-term (1, 4, 12 weeks after the procedure), and long-term (20 - 48 weeks after the procedure) OTE is an outcome measure with 9 choices: going from -4: it has become insupportable, in the middle 0: unchanged, and at the end +4: the symptoms have completely resolved.
Time frame: 1-48 weeks
Patients experience and satisfaction of the treatment using overall symptom severity
Patients experience and satisfaction of the treatment based on OSS short-term (1, 4, 12 weeks after the procedure), and long-term (20 - 48 weeks after the procedure)
Time frame: 1-48 weeks
Evolution of associated abdominal bloating using a VAS score for symptom severity
Evolution of associated abdominal bloating short-term (1, 4, 12 weeks) and long-term (20 - 48 weeks after the procedure).
Time frame: 1-48 weeks
Evolution of associated abdominal/thoracic pain using a VAS score for symptom severity
Evolution of associated abdominal/thoracic pain short-term (1, 4, 12 weeks) and long-term (20 - 48 weeks after the procedure).
Time frame: 1-48 weeks
Evolution of associated flatulence using a VAS score for symptom severity
Evolution of associated flatulence short-term (1, 4, 12 weeks) and long-term (20 - 48 weeks after the procedure).
Time frame: 1-48 weeks
Evolution of associated gurgling noises using a VAS score for symptom severity
Evolution of associated gurgling noises short-term (1, 4, 12 weeks) and long-term (20 - 48 weeks after the procedure).
Time frame: 1-48 weeks
Safety during follow-up, with SSQ at week 12, 20 and 48.
Safety during follow-up, with SSQ at week 12, 20 and 48.
Time frame: 12-48 weeks
Change in objective measurement of UES pressure upon belching during high resolution impedance manometry
Change in objective measurements after, versus before BT injeciton using high resolution impedance manometry at week 20, and comparing with baseline.
Time frame: 20 weeks
Change in objective measurement of oscillatory movement of air during high resolution impedance manometry
Change in objective measurements after, versus before BT injeciton using high resolution impedance manometry at week 20, and comparing with baseline.
Time frame: 20 weeks
Improvement of symptoms not reaching primary outcome
Improvement in symptoms after Botox versus placebo, 12 and 48 weeks after treatment. We will use the questionnaire of 'Difficulties with belching', using a cut-off for improvement of 30% on question 6A 'To what extent have the symptoms of \'difficulty burping air\' been reduced after treatment?\'.
Time frame: 48 weeks
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 ↗
This study is completed, as verified in Dec 2025. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Botulinum toxin type A
AZ Delta