Botulinum Toxin in the Palatopharyngeal Muscle for the Treatment of Obstructive Sleep Apnea (ARAP1)

February 5, 2026 updated by: Alan Rodrigues de Almeida Paiva, Hospital Felicio Rocho

EVALUATION OF BOTULINUM TOXIN IN THE PALATOPHARYNGEAL MUSCLE FOR THE TREATMENT OF OBSTRUCTIVE SLEEP APNEA

Obstructive Sleep Apnea (OSA) is a sleep-related breathing disorder characterized by recurrent collapse of the upper airway during sleep, in which the palatopharyngeal muscle plays a key role in pathophysiology. Although continuous positive airway pressure (CPAP) remains the standard treatment, adherence is often suboptimal. Botulinum toxin type A (BoNT-A), a peripheral neuromodulator, has been proposed as a potential therapeutic alternative by inducing chemodenervation and muscle volume reduction, thereby potentially increasing upper airway patency. This study aims to evaluate the efficacy and safety of BoNT-A injection into the palatopharyngeal muscle in patients with moderate to severe OSA. This is a prospective, single-arm, interventional clinical trial with pre- and post-intervention assessment. We hypothesize that the intervention will result in a significant reduction in the Apnea-Hypopnea Index (AHI), along with improvements in secondary outcomes such as excessive daytime sleepiness and oxygenation parameters.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
20

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Diagnosis of moderate to severe OSA, confirmed by home or laboratory polysomnography.
  • Age between 18 and 50 years.
  • BMI in the range of 18.5-30.
  • Neck circumference ≤ 44 cm (men) and ≤ 42 cm (women).
  • Absence of signs of upper obstruction

Exclusion Criteria:

  • Skeletal or craniofacial disorders:
  • Tonsillar hypertrophy 3-4
  • Obesity (BMI > 30 kg/m²)
  • Elderly (age > 50 years)
  • Neuromuscular diseases (e.g., dystrophies, myasthenia gravis)
  • Chronic use of medications that alter muscle tone.
  • Excessive alcohol consumption (> 14 drinks/week)
  • Chronic obstructive pulmonary disease (COPD)
  • Congestive heart failure (NYHA III-IV) or decompensated heart disease.
  • Concomitant sleep disorders: narcolepsy, restless legs syndrome, sleep behavior disorder (REM).
  • Predominant central or mixed sleep apnea on polysomnography (≥ 50% central events).
  • Previous airway surgery (uvulopalatopharyngoplasty, recent tonsillectomy).
  • Pregnancy or postpartum (< 6 months).
  • Neurological conditions: Previous stroke, Parkinson's disease, dementia.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Botulinum toxin
BOTULINUM TOXIN IN THE PALATOPHARYGEUS MUSCLE
Drug: BOTULINUM TOXIN IN THE PALATOPHARYGEUS MUSCLE
Botulinum toxin will be injected into the palatopharyngeal muscle in patients undergoing Medication-Induced Sleep Endoscopy. The injection will be performed while visualizing the posterior pharyngeal constriction.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Apnea-Hypopnea Index (AHI)
Time Frame: 12 months
Evaluate the variation in the Apnea-Hypopnea Index (AHI) before and 3 months after the intervention.
12 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Minimum oxygen saturation (SpO₂)
Time Frame: 12 months
Verify the impact of the intervention on minimum oxygen saturation (SpO₂)
12 months
Epworth Sleepiness Scale
Time Frame: 12 months
Analyze the change in excessive daytime sleepiness, using the Epworth Sleepiness Scale, before and after the application of botulinum toxin.
12 months
Oxygen desaturation index (ODI).
Time Frame: 12 months
Verify the impact of the intervention on oxygen desaturation index (ODI).
12 months

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Adverse events
Time Frame: 12 months
Monitor the occurrence of adverse events related to the procedure and the application of the toxin, aiming to describe the safety profile of the intervention.
12 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Hospital Felicio Rocho

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 5, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 2, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 5, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 10, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 10, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 5, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 90369725.9.0000.5125
  • 121415 (Other Identifier: Hospital Felicio Rocho)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Age, Weight, Height, Sex, Test Results, Questionnaire Results, Contact Telephone Number, Intervention Location, Information on Procedures, Procedure Videos

IPD Sharing Time Frame

From the beginning to the end of the study

IPD Sharing Access Criteria

Contact the principal investigator via email or phone

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • ANALYTIC_CODE
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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