Adductor Spasmodic DysphoniaPhase 1/2NCT05158166
DaxibotulinumtoxinA Injection for Treatment of Adductor Spasmodic Dysphonia
A Phase 1/2 study testing DaxibotulinumtoxinA in people with Adductor Spasmodic Dysphonia and Voice Disorders, run by University of California, San Francisco at 1 site in United States.
Trial summary
Spasmodic Dysphonia (SD) is a neurologic condition causing inappropriate contraction of the laryngeal musculature, leading to abnormal voicing. The three types (adductor, abductor, and mixed) affect varying muscle groups which produce characteristic voice patterns. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Adductor Spasmodic Dysphonia, Voice Disorders, Spasmodic Dysphonia
- What is being tested?
- DaxibotulinumtoxinA
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 22 participants
- Where
- 1 siteUnited States
- Study dates
- 13 Oct 2023to 2 Mar 2025
- Phase
- Phase 1/2
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- greater than 18
- diagnosis of adductor spasmodic dysphonia
- previous successful treatment with BotoxA
- stabilized dose for last 3 treatments
Who cannot join
- age less than 18
- exclusively having other neurologic conditions such as:
- abductor spasmodic dysphonia
- ALS
- Multiple sclerosis
- Parkinson's disease
- Essential tremor
Trial locations and contacts
1 site in 1 country.
About this study
Spasmodic Dysphonia (SD) is a neurologic condition causing inappropriate contraction of the laryngeal musculature, leading to abnormal voicing. The three types (adductor, abductor, and mixed) affect varying muscle groups which produce characteristic voice patterns. The vast majority of patients with SD have adductor type, which impacts the lateral cricoarytenoid and thyroarytenoid muscle complex. While many treatment modalities have been investigated, the most effective treatment is botulinum toxin injection to these muscle groups, performed transcervically with or without electromyography (EMG) guidance. Patients undergoing this treatment typically require re-injection every 3 months. Due to its specialized nature, the laryngeal injections are not performed routinely outside of academic medical centers; thus, patients may come from a distance to receive this treatment. Both due to the significant impact on voice quality when the injections wear off and the sometimes challenging access to treatment, a longer-acting agent is desired.
Injectible daxibotuliumtoxinA (DAXI, Revance Therapeutics Inc., Newark, CA) has been shown in large clinical trials to provide safe, effective treatment for glabellar lines and cervical dystonia and may offer a longer-lasting result when compared with onabotulinumtoxinA.
Thus, a study examining the effect of DAXI for patients with adductor spasmodic dysphonia is proposed. This study aims to assess the efficacy of DAXI for transcervical laryngeal injection in patients with adductor spasmodic dysphonia.
- Being tested
- DaxibotulinumtoxinA
- Keywords
- adductor spasmodic dysphonia
- Medical subject headings
- Voice Disorders, Dysphonia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DaxibotulinumtoxinADrug
Also called DAXI
This is a long-acting alternative to traditional Botox A treatment.
| Study group | Role | What they receive |
|---|---|---|
| Administration of Daxi | Experimental | Injectible daxibotulinumtoxinA (DAXI, Revance Therapeutics Inc., Newark, CA) is an investigational botulinum toxin type A which has been shown in large clinical trials to provide safe, effective treatment for glabellar lines and cervical dystonia and may offer longer-lasting results when compared with onabotulinumtoxinA. Dosage will be same number of units as prior Botox A dose. Receives: Drug: DaxibotulinumtoxinA |
What is being measured
The primary outcome is the main question the study is designed to answer.
Our Primary Outcome is the Difference in VHI-10 Score at 30 Days After Injection With DAXI.
The Voice Handicap Index-10 (VHI-10) is a patient-reported questionnaire (range 0-40) that measures voice-related handicap, with higher scores indicating greater severity. Difference between baseline and 30 days post DAXI injection scores will be determined using a paired t-test with subjects pre-treatment VHI-10 scores as a control.
Measured: 30 days
Secondary outcomes (1)
A Secondary Outcome Will be Comparing the Duration of Effect of DAXI With Patients' Prior Botox Treatment.
Duration of Voice Benefit (DVB) was determined by calculating the difference of time (in days) between injection date and time the patient reported a significant reduction of benefit that would prompt scheduling a repeat treatment. DVB is routinely calculated for all Adductor-type laryngeal dystonia (AdLD) patients during their return visits by asking "how many days ago did you lose injection benefit such that you felt you needed another injection." This time frame was then subtracted from the number of days between injection dates to calculate DVB. For Botox (BtxA), a mean DVB was calculated by averaging the last three DVB values from successful injections to compare to the Daxi DVB. Clinically significant difference in DVB was a priori determined as > 14 days between values to allow for normal inter-injection variability.
Measured: Up to 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Dec 2021
- Study start13 Oct 2023
- Primary completion1 Mar 2025
- Study completion2 Mar 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for Adductor Spasmodic DysphoniaStudies of the same condition, open and under way.
- More trials run by University of California, San FranciscoThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1/2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 22 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of California, San Francisco
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Clark Rosen, MD, Principal investigator, University of California, San Francisco
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05158166
- Sponsor's protocol ID
- 21-33778
- Status last verified
- Apr 2026
- First submitted
- 19 Nov 2021
- Last updated
- 18 May 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Carruthers J, Solish N, Humphrey S, Rosen N, Muhn C, Bertucci V, Swift A, Metelitsa A, Rubio RG, Waugh J, Quiring J, Shears G, Carruthers A. Injectable DaxibotulinumtoxinA for the Treatment of Glabellar Lines: A Phase 2, Randomized, Dose-Ranging, Double-Blind, Multicenter Comparison With OnabotulinumtoxinA and Placebo. Dermatol Surg. 2017 Nov;43(11):1321-1331. doi: 10.1097/DSS.0000000000001206.
PubMed 28614091Jankovic J, Truong D, Patel AT, Brashear A, Evatt M, Rubio RG, Oh CK, Snyder D, Shears G, Comella C. Injectable DaxibotulinumtoxinA in Cervical Dystonia: A Phase 2 Dose-Escalation Multicenter Study. Mov Disord Clin Pract. 2018 Apr 26;5(3):273-282. doi: 10.1002/mdc3.12613. eCollection 2018 May-Jun.
PubMed 30009213Carruthers JD, Fagien S, Joseph JH, Humphrey SD, Biesman BS, Gallagher CJ, Liu Y, Rubio RG; SAKURA 1 and SAKURA 2 Investigator Group; SAKURA 1 and SAKURA 2 Investigator Group includes the following. DaxibotulinumtoxinA for Injection for the Treatment of Glabellar Lines: Results from Each of Two Multicenter, Randomized, Double-Blind, Placebo-Controlled, Phase 3 Studies (SAKURA 1 and SAKURA 2). Plast Reconstr Surg. 2020 Jan;145(1):45-58. doi: 10.1097/PRS.0000000000006327.
PubMed 31609882Stone HF, Zhu Z, Thach TQ, Ruegg CL. Characterization of diffusion and duration of action of a new botulinum toxin type A formulation. Toxicon. 2011 Aug;58(2):159-67. doi: 10.1016/j.toxicon.2011.05.012. Epub 2011 May 31.
PubMed 21658400Rumbach A, Aiken P, Novakovic D. RETRACTED: Outcome Measurement in the Treatment of Spasmodic Dysphonia: A Systematic Review of the Literature. J Voice. 2019 Sep;33(5):810.e13-810.e39. doi: 10.1016/j.jvoice.2018.03.011. Epub 2018 Apr 11.
PubMed 29655932
Study at a glance
From the registry record, last updated by the sponsor on 18 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- DaxibotulinumtoxinA Injection for Treatment of Adductor Spasmodic Dysphonia
- ClinicalTrials.gov ID
- NCT05158166
- Acronym / sponsor ID
- 21-33778
- Keywords
- adductor spasmodic dysphonia
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 22 participants (actual)
- Lead sponsor
- University of California, San FranciscoUniversity, hospital or other
- Study start
- 13 Oct 2023 (actual)
- Primary completion
- 1 Mar 2025 (actual)
- Study completion
- 2 Mar 2025 (actual)
- First posted
- 15 Dec 2021 (actual)
- Results
- Posted 27 Mar 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Spasmodic Dysphonia (SD) is a neurologic condition causing inappropriate contraction of the laryngeal musculature, leading to abnormal voicing. The three types (adductor, abductor, and mixed) affect varying muscle groups which produce characteristic voice patterns. The vast majority of patients with SD have adductor type, which impacts the lateral cricoarytenoid and thyroarytenoid muscle complex. While many treatment modalities have been investigated, the most effective treatment is botulinum toxin injection to these muscle groups, performed transcervically with or without electromyography (EMG) guidance. Patients undergoing this treatment typically require re-injection every 3 months. Due to its specialized nature, the laryngeal injections are not performed routinely outside of academic medical centers; thus, patients may come from a distance to receive this treatment. Both due to the significant impact on voice quality when the injections wear off and the sometimes challenging access to treatment, a longer-acting agent is desired.
Injectible daxibotuliumtoxinA (DAXI, Revance Therapeutics Inc., Newark, CA) has been shown in large clinical trials to provide safe, effective treatment for glabellar lines and cervical dystonia and may offer a longer-lasting result when compared with onabotulinumtoxinA.
Thus, a study examining the effect of DAXI for patients with adductor spasmodic dysphonia is proposed. This study aims to assess the efficacy of DAXI for transcervical laryngeal injection in patients with adductor spasmodic dysphonia.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Administration of Daxi | Experimental | Drug: DaxibotulinumtoxinAInjectible daxibotulinumtoxinA (DAXI, Revance Therapeutics Inc., Newark, CA) is an investigational botulinum toxin type A which has been shown in large clinical trials to provide safe, effective treatment for glabellar lines and cervical dystonia and may offer longer-lasting results when compared with onabotulinumtoxinA. Dosage will be same number of units as prior Botox A dose. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- greater than 18
- diagnosis of adductor spasmodic dysphonia
- previous successful treatment with BotoxA
- stabilized dose for last 3 treatments
Key exclusion criteria (7 listed)
- age less than 18
- exclusively having other neurologic conditions such as:
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| DaxibotulinumtoxinAAlso: DAXIThis is a long-acting alternative to traditional Botox A treatment. | Drug | Administration of Daxi |
Primary outcome
Our Primary Outcome is the Difference in VHI-10 Score at 30 Days After Injection With DAXI.
Time frame: 30 days
The Voice Handicap Index-10 (VHI-10) is a patient-reported questionnaire (range 0-40) that measures voice-related handicap, with higher scores indicating greater severity. Difference between baseline and 30 days post DAXI injection scores will be determined using a paired t-test with subjects pre-treatment VHI-10 scores as a control.
1 secondary outcome
A Secondary Outcome Will be Comparing the Duration of Effect of DAXI With Patients' Prior Botox Treatment.
Time frame: Up to 1 year
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 May 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Background: PubMed 28614091Carruthers J, Solish N, Humphrey S, Rosen N, Muhn C, Bertucci V, Swift A, Metelitsa A, Rubio RG, Waugh J, Quiring J, Shears G, Carruthers A. Injectable DaxibotulinumtoxinA for the Treatment of Glabellar Lines: A Phase 2, Randomized, Dose-Ranging, Double-Blind, Multicenter Comparison With OnabotulinumtoxinA and Placebo. Dermatol Surg. 2017 Nov;43(11):1321-1331. doi: 10.1097/DSS.0000000000001206.
- Background: PubMed 30009213Jankovic J, Truong D, Patel AT, Brashear A, Evatt M, Rubio RG, Oh CK, Snyder D, Shears G, Comella C. Injectable DaxibotulinumtoxinA in Cervical Dystonia: A Phase 2 Dose-Escalation Multicenter Study. Mov Disord Clin Pract. 2018 Apr 26;5(3):273-282. doi: 10.1002/mdc3.12613. eCollection 2018 May-Jun.
- Background: PubMed 31609882Carruthers JD, Fagien S, Joseph JH, Humphrey SD, Biesman BS, Gallagher CJ, Liu Y, Rubio RG; SAKURA 1 and SAKURA 2 Investigator Group; SAKURA 1 and SAKURA 2 Investigator Group includes the following. DaxibotulinumtoxinA for Injection for the Treatment of Glabellar Lines: Results from Each of Two Multicenter, Randomized, Double-Blind, Placebo-Controlled, Phase 3 Studies (SAKURA 1 and SAKURA 2). Plast Reconstr Surg. 2020 Jan;145(1):45-58. doi: 10.1097/PRS.0000000000006327.
- Background: PubMed 21658400Stone HF, Zhu Z, Thach TQ, Ruegg CL. Characterization of diffusion and duration of action of a new botulinum toxin type A formulation. Toxicon. 2011 Aug;58(2):159-67. doi: 10.1016/j.toxicon.2011.05.012. Epub 2011 May 31.
- Background: PubMed 29655932Rumbach A, Aiken P, Novakovic D. RETRACTED: Outcome Measurement in the Treatment of Spasmodic Dysphonia: A Systematic Review of the Literature. J Voice. 2019 Sep;33(5):810.e13-810.e39. doi: 10.1016/j.jvoice.2018.03.011. Epub 2018 Apr 11.
- Individual participant dataSharing planned: No
Related trials for Adductor Spasmodic Dysphonia
RecruitingObservational study
Deep Brain Stimulation for Laryngeal Dystonia: From Mechanism to Optimal Application
Laryngeal Dystonia, Adductor Spastic Dysphonia of Dystonia
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Clark Rosen, MD principal investigator
University of California, San Francisco
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing DaxibotulinumtoxinA in people with Adductor Spasmodic Dysphonia and Voice Disorders, run by University of California, San Francisco at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 18 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 27 Mar 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Our Primary Outcome is the Difference in VHI-10 Score at 30 Days After Injection With DAXI. (time frame: 30 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05158166, which also lists 5 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 May 2026.