Multisystemic Smooth Muscle Dysfunction SyndromeNCT07574034
A Single Patient Study of Sapropterin for Multisystem Smooth Muscle Dysfunction Syndrome
A study testing Kuvan (Sapropterine) in people with Multisystemic Smooth Muscle Dysfunction Syndrome, run by Gregor Andelfinger at 1 site in Canada.
Trial summary
There is currently no approved treatment for multisystem smooth muscle dysfunction syndrome (MSMDS). This single-patient study is the first to be conducted in a child with MSMDS in Canada and was designed to provide the child with access to sapropterin treatment. Read more about this study
- Who is it for?
- Ages 1 month to 18 years
- Conditions the study is for
- Multisystemic Smooth Muscle Dysfunction Syndrome
- What is being tested?
- Kuvan (Sapropterine)
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 1 participants
- Where
- 1 siteCanada
- Study dates
- 15 Jul 2026to 1 Jun 2030
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 1 month to 18 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Patients with the following molecularly confirmed genotype: ACTA2 c.536G>A, p.Arg179His
- Aged 1 month to 18 years
Who cannot join
- Previous exposure to Kuvan®, Biopten®, or any preparation of tetrahydrobiopterin for greater
- Known hypersensitivity to Kuvan® or its excipients
- Known hypersensitivity to other approved or non-approved formulations of tetrahydrobiopterin
- Current use of medications that are known to affect nitric oxide synthesis, metabolism or action
- Current use of experimental/other investigational or unregistered drugs that may affect the study outcomes
- Inability to comply with study procedures
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- Concurrent disease or condition that would interfere with study participation or increase the risk for adverse events, including stroke, renal or hepatic failure
- Other significant disease that in the Investigator's opinion would exclude the subject from the trial
- Any condition that, in the view of the Principal Investigator renders the subject at high risk for failure to comply with treatment or to complete the study
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site, 1 recruiting
- Recruiting
CHU Sainte-Justine
Montreal, Quebec, H3T 1C5
Nawel Akli, 514-345-4931 ext. 3512, nawel.akli2.hsj@ssss.gouv.qc.ca
About this study
Official title: A Single Patient Study (SPS) of Sapropterin for Multisystem Smooth Muscle Dysfunction Syndrome (MSMDS).
There is currently no approved treatment for multisystem smooth muscle dysfunction syndrome (MSMDS). This single-patient study is the first to be conducted in a child with MSMDS in Canada and was designed to provide the child with access to sapropterin treatment. The molecule that will be used, sapropterin (Kuvan), is already approved and available for other indications. This disease is caused by a genetic variant in the ACTA2 gene. This variant prevents the small units of actin fibers, which are the molecular motors of the smooth muscle cell, from assembling correctly. The goal is to gather data so that the drug can be approved for this indication and thus treat the patient.
Read the detailed description
The plan is to repurpose sapropteride, a synthetic form of tetrahydrobiopterin (BH4), an essential cofactor of phenylalanine hydroxylase (PAH). Sapropteride is already approved in Canada for the treatment of phenylketonuria (PKU) and has shown promise as an agent against multisystem smooth muscle dysfunction syndrome (MSMS) in an animal model. No clinical trials are currently underway with sapropteride for MSMS.
- Being tested
- Kuvan (Sapropterine)
- Keywords
- multisystemic smooth muscle dysfunction syndrome, MSMDS, Sapropterine, Kuvan
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Kuvan (Sapropterine)Drug
Sapropterine is already approved in Canada for the treatment of phenylketonuria (PKU) and has shown promise as an agent against multisystem smooth muscle dysfunction syndrome (MSMS) in an animal model. No clinical trials are currently underway with sapropteride for MSMS.
| Study group | Role | What they receive |
|---|---|---|
| Open label Intervention | Experimental | Participant will receive KUVAN® (sapropterin dihydrochloride) 100 mg Powder Packets once daily. Receives: Drug: Kuvan (Sapropterine) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Crossing of percentile of growth
Measured: 2 years
Increase of mean diastolic blood pressure by more than 8 mmHg
Measured: 2 years
Absence of cerebral vascular complications
Measured: 2 years
Absence of progression of cerebral vascular disease
Measured: 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 May 2026
- Study start15 Jul 2026
- Primary completion1 Jun 2028 (estimated)
- Study completion1 Jun 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Multisystemic Smooth Muscle Dysfunction SyndromeStudies of the same condition, open and under way.
- 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 N/A
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- This is a single patient study (SPS)
- Masking
- None (open label)
- Enrolment
- 1 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Gregor Andelfinger
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Gregor Andelfinger, St. Justine's Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07574034
- Sponsor's protocol ID
- SPS-MSMDS
- Status last verified
- Mar 2026
- First submitted
- 1 May 2026
- Last updated
- 5 Nov 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Krishnan V, Rahman A, Das S, Weil M, Altman S, Shamber C, Fong CT, Goldstein AM, Lindsay ME, Musolino P. A novel drug Sapropterin (Kuvan) ameliorates the disease phenotype in a mouse model of multisystem smooth muscle dysfunction syndrome. Child Neurology Society Meeting Vancouver. 2023.
Study at a glance
From the registry record, last updated by the sponsor on 5 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Single Patient Study (SPS) of Sapropterin for Multisystem Smooth Muscle Dysfunction Syndrome (MSMDS).
- ClinicalTrials.gov ID
- NCT07574034
- Acronym / sponsor ID
- SPS-MSMDS
- Keywords
- multisystemic smooth muscle dysfunction syndrome, MSMDS, Sapropterine, Kuvan
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 1 participants (estimated)
- Lead sponsor
- Gregor AndelfingerUniversity, hospital or other
- Study start
- 15 Jul 2026 (actual)
- Primary completion
- 1 Jun 2028 (estimated)
- Study completion
- 1 Jun 2030 (estimated)
- First posted
- 7 May 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
There is currently no approved treatment for multisystem smooth muscle dysfunction syndrome (MSMDS). This single-patient study is the first to be conducted in a child with MSMDS in Canada and was designed to provide the child with access to sapropterin treatment. The molecule that will be used, sapropterin (Kuvan), is already approved and available for other indications. This disease is caused by a genetic variant in the ACTA2 gene. This variant prevents the small units of actin fibers, which are the molecular motors of the smooth muscle cell, from assembling correctly. The goal is to gather data so that the drug can be approved for this indication and thus treat the patient.
Detailed description
The plan is to repurpose sapropteride, a synthetic form of tetrahydrobiopterin (BH4), an essential cofactor of phenylalanine hydroxylase (PAH). Sapropteride is already approved in Canada for the treatment of phenylketonuria (PKU) and has shown promise as an agent against multisystem smooth muscle dysfunction syndrome (MSMS) in an animal model. No clinical trials are currently underway with sapropteride for MSMS.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- This is a single patient study (SPS)
| Arm | Type | Receives |
|---|---|---|
| Open label Intervention | Experimental | Drug: Kuvan (Sapropterine)Participant will receive KUVAN® (sapropterin dihydrochloride) 100 mg Powder Packets once daily. |
Who may qualify
- Ages
- 1 month to 18 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (2 listed)
- Patients with the following molecularly confirmed genotype: ACTA2 c.536G>A, p.Arg179His
- Aged 1 month to 18 years
Key exclusion criteria (9 listed)
- Previous exposure to Kuvan®, Biopten®, or any preparation of tetrahydrobiopterin for greater
- Known hypersensitivity to Kuvan® or its excipients
- Known hypersensitivity to other approved or non-approved formulations of tetrahydrobiopterin
- Current use of medications that are known to affect nitric oxide synthesis, metabolism or action
- Current use of experimental/other investigational or unregistered drugs that may affect the study outcomes
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 |
|---|---|---|
| Kuvan (Sapropterine)Sapropterine is already approved in Canada for the treatment of phenylketonuria (PKU) and has shown promise as an agent against multisystem smooth muscle dysfunction syndrome (MSMS) in an animal model. No clinical trials are currently underway with sapropteride for MSMS. | Drug | Open label Intervention |
Primary outcome
Crossing of percentile of growth
Time frame: 2 years
Increase of mean diastolic blood pressure by more than 8 mmHg
Time frame: 2 years
Absence of cerebral vascular complications
Time frame: 2 years
Absence of progression of cerebral vascular disease
Time frame: 2 years
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Nov 2026.
- BackgroundKrishnan V, Rahman A, Das S, Weil M, Altman S, Shamber C, Fong CT, Goldstein AM, Lindsay ME, Musolino P. A novel drug Sapropterin (Kuvan) ameliorates the disease phenotype in a mouse model of multisystem smooth muscle dysfunction syndrome. Child Neurology Society Meeting Vancouver. 2023.
- Individual participant dataSharing planned: No
Related trials for Multisystemic Smooth Muscle Dysfunction Syndrome
RecruitingObservational study
A Retrospective and Prospective Natural History of Genetic Vasculopathies
Multisystemic Smooth Muscle Dysfunction Syndrome, ACTA2
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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Kuvan (Sapropterine) in people with Multisystemic Smooth Muscle Dysfunction Syndrome, run by Gregor Andelfinger at 1 site in Canada.
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 2 inclusion and 9 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: looking for participants now, as of the sponsor's last update on 5 Nov 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 Canada. 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.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Crossing of percentile of growth (time frame: 2 years). The study lists 4 primary outcomes in all. 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 NCT07574034, which also lists 1 linked publication.
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 5 Nov 2026.