Mast Cell Activation SyndromePhase 2NCT05652907
Safety and Efficacy of FSD201 for the Treatment of Chronic Pain Associated With Idiopathic MCAS (MCAD)
A Phase 2 study testing FSD201 in people with Mast Cell Activation Syndrome and Mast Cell Activation Disorder Idiopathic, run by Quantum Biopharma at 3 sites in 2 countries.
Trial summary
This study will determine if FSD201 reduces the average daily 24-hour recall pain intensity after 28 and 56 days of treatment in adults with chronic widespread musculoskeletal nociplastic pain. Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Mast Cell Activation Syndrome, Mast Cell Activation Disorder Idiopathic
- What is being tested?
- FSD201
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 2 participants
- Where
- 3 sitesin 2 countries
- Study dates
- 19 Jan 2023to 24 May 2023
- Phase
- Phase 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 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Clinical diagnosis of idiopathic MCAS as per the global consensus diagnostic criteria
- Adults with widespread chronic pain (in three or more body regions);
- Chronic pains of intensity greater than or equal to 4.0 but less than or equal to 9.0 on a Numeric Pain Rating Scale, symptom duration of more than 6 months;
- Subject agrees to use only acetaminophen (up to 1000 mg per dose and not to exceed 3000 mg/day) or diphenhydramine (up to 300 mg/day) as rescue medication for chronic widespread musculoskeletal nociplastic pains throughout the trial;
- The subject is willing to maintain current activity and exercise levels throughout the study;
- During the study, the subject agrees not to initiate or change any non-pharmacologic interventions (including chiropractic care, physical therapy, psychotherapy, and massage therapy). Any ongoing non-pharmacologic intervention must be stable for at least 4 weeks before screening and should be continued for the duration of the study;
Who cannot join
- The subject has pain that cannot be clearly differentiated from or that could interfere with the assessment of chronic musculoskeletal nociplastic pain secondary likely to idiopathic MCAS (post-herpetic neuralgia, traumatic injury, prior surgery, complex regional pain syndrome);
- Adults with chronic cancer pain;
- Adults with inflammatory connective tissue disorder or rheumatological disorder-related pain, for example rheumatoid arthritis;
- Adults with focal musculoskeletal pain;
- Adults with skin diseases (chronic urticaria, pemphigus, lupus, rosacea etc.);
- Adults with endocrinological disorders (acute hypothyroidism, acute adrenal insufficiency etc.);
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- Adults with systemic gastrointestinal conditions (Inflammatory bowel disorders);
- Significant psychological comorbidities: PHQ-9 score greater than 20; and GAD-7 score greater than 15 (indication of severe anxiety that could interfere with accurate logging of pain ratings);
- Current or recent (within 12 months of screening) history of a substance use disorder including cannabinoid or alcohol use disorder as defined by the Diagnostic and Statistical Manual of Mental Disorders (5th edition; DSM-5);
- Subject has neurologic disorder unrelated to chronic widespread musculoskeletal nociplastic pains (phantom limb from amputation, vitamin B12 deficiency, chronic inflammatory demyelinating polyneuropathy), circulatory disorder (peripheral artery disease), a skin condition in the area of neuropathy that could alter sensation (plantar ulcer), or other painful conditions (arthritis) that could interfere with reporting of pain due to chronic widespread musculoskeletal nociplastic pains;
- Current severe or uncontrolled major depressive disorder or anxiety disorders. Mild to moderate major depression or anxiety disorders are permitted provided that the investigator assesses the patient as clinically stable and appropriate for entry into the study. Stable doses of SSRIs are allowed for the treatment of depression if the dose is stable for 60 days before Screening Visit;
- Subject has a history of suicide attempt or suicidal behaviour within the last 12 months or has suicidal ideation within the previous 12 months or who is at significant risk to commit suicide, as judged by the Investigator at Screening and/or Randomization Visit;
- Patients with active malignancy or history of malignancy, except for basal cell or squamous cell carcinoma and actinic keratosis. Basal cell carcinoma and small squamous cell carcinoma of the skin which have been excised according to guidelines within the last 5 years or in situ cervical carcinoma that has been fully treated and shows no evidence of recurrence are allowed;
- Individuals with generalized joint hypermobility secondary to hereditary connective tissue disorders like Ehlers Danlos Syndrome;
- Individuals with high baseline serum tryptase levels suggestive of Primary or Secondary MCAS (defined as above the normal range of 2.2 to 13.2 µg/L).
Trial locations and contacts
3 sites in 2 countries.
3 sites in 2 countries
United States2 sites
Norman Marcus Pain Institute
New York, New York, 10016
Saint Charles Clinical Research
Weldon Spring, Missouri, 63304
About this study
Official title: A Randomized, Double-Blind Placebo Controlled Parallel Group Study of Safety and Efficacy of FSD201 in Patients With Chronic Widespread Musculoskeletal Nociplastic Pain Associated With Idiopathic Mast Cell Activation Syndrome (Disorder)
This study will determine if FSD201 reduces the average daily 24-hour recall pain intensity after 28 and 56 days of treatment in adults with chronic widespread musculoskeletal nociplastic pain.
- Being tested
- FSD201, Placebo
- Medical subject headings
- Mast Cell Activation Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
FSD201Drug
Tablets for oral administration.
PlaceboDrug
Placebo tablets matched to FSD201 for oral administration.
| Study group | Role | What they receive |
|---|---|---|
| FSD201 | Experimental | Participants will receive 600 milligrams (mg) FSD201 tablet twice daily (BID) orally from Day 0 to Day 56. Receives: Drug: FSD201 |
| Placebo | Placebo comparator | Participants will receive placebo matched to 600 mg FSD201 tablets twice daily (BID) orally from Day 0 to Day 56. Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Targeted Treatment Effect of 30% Decrease From Baseline to Day 28 in the Average Daily Pain Intensity
Targeted treatment effect of 30% decrease from baseline to Day 28 in the average daily pain intensity score measured by an 11-point numerical pain rating scale (NPRS). NPRS is an 11-point scale from 0 to10 where the higher number indicates worse pain.
Averages will be calculated as follows: Baseline: calculated weekly average from Day -7 to Day -1 Day 28: calculated weekly average from Day 22 to Day 28
Measured: Day 28
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Dec 2022
- Study start19 Jan 2023
- Primary completion24 May 2023
- Study completion24 May 2023
Why it stopped: For business reasons and not for reasons related to safety or efficacy
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.
- Other trials for Mast Cell Activation 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 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 2 participants (actual)
Sponsor and investigators
- Lead sponsor
- Quantum Biopharma
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Andrzej Chruscinski, MD, Study director, FSD Pharma
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05652907
- Sponsor's protocol ID
- FSD201-010
- Status last verified
- Feb 2023
- First submitted
- 23 Nov 2022
- Last updated
- 21 Apr 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 21 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized, Double-Blind Placebo Controlled Parallel Group Study of Safety and Efficacy of FSD201 in Patients With Chronic Widespread Musculoskeletal Nociplastic Pain Associated With Idiopathic Mast Cell Activation Syndrome (Disorder)
- ClinicalTrials.gov ID
- NCT05652907
- Acronym / sponsor ID
- FSD201-010
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: For business reasons and not for reasons related to safety or efficacy
- Enrolment
- 2 participants (actual)
- Lead sponsor
- Quantum BiopharmaIndustry (pharma, biotech, devices)
- Study start
- 19 Jan 2023 (actual)
- Primary completion
- 24 May 2023 (actual)
- Study completion
- 24 May 2023 (actual)
- First posted
- 15 Dec 2022 (actual)
- Results
- Posted 21 Apr 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study will determine if FSD201 reduces the average daily 24-hour recall pain intensity after 28 and 56 days of treatment in adults with chronic widespread musculoskeletal nociplastic pain.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| FSD201 | Experimental | Drug: FSD201Participants will receive 600 milligrams (mg) FSD201 tablet twice daily (BID) orally from Day 0 to Day 56. |
| Placebo | Placebo comparator | Drug: PlaceboParticipants will receive placebo matched to 600 mg FSD201 tablets twice daily (BID) orally from Day 0 to Day 56. |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Clinical diagnosis of idiopathic MCAS as per the global consensus diagnostic criteria
- Adults with widespread chronic pain (in three or more body regions);
- Chronic pains of intensity greater than or equal to 4.0 but less than or equal to 9.0 on a Numeric Pain Rating Scale, symptom duration of more than 6 months;
- Subject agrees to use only acetaminophen (up to 1000 mg per dose and not to exceed 3000 mg/day) or diphenhydramine (up to 300 mg/day) as rescue medication for chronic widespread musculoskeletal nociplastic pains throughout the trial;
- The subject is willing to maintain current activity and exercise levels throughout the study;
Key exclusion criteria (15 listed)
- The subject has pain that cannot be clearly differentiated from or that could interfere with the assessment of chronic musculoskeletal nociplastic pain secondary likely to idiopathic MCAS (post-herpetic neuralgia, traumatic injury, prior surgery, complex regional pain syndrome);
- Adults with chronic cancer pain;
- Adults with inflammatory connective tissue disorder or rheumatological disorder-related pain, for example rheumatoid arthritis;
- Adults with focal musculoskeletal pain;
- Adults with skin diseases (chronic urticaria, pemphigus, lupus, rosacea etc.);
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 |
|---|---|---|
| FSD201Tablets for oral administration. | Drug | FSD201 |
| PlaceboPlacebo tablets matched to FSD201 for oral administration. | Drug | Placebo |
Primary outcome
Targeted Treatment Effect of 30% Decrease From Baseline to Day 28 in the Average Daily Pain Intensity
Time frame: Day 28
Targeted treatment effect of 30% decrease from baseline to Day 28 in the average daily pain intensity score measured by an 11-point numerical pain rating scale (NPRS). NPRS is an 11-point scale from 0 to10 where the higher number indicates worse pain. Averages will be calculated as follows: Baseline: calculated weekly average from Day -7 to Day -1 Day 28: calculated weekly average from Day 22 to Day 28
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Apr 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No
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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.
Andrzej Chruscinski, MD study director
FSD Pharma
3 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing FSD201 in people with Mast Cell Activation Syndrome and Mast Cell Activation Disorder Idiopathic, run by Quantum Biopharma at 3 sites in 2 countries.
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 6 inclusion and 15 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: stopped early, as of the sponsor's last update on 21 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in United States, 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. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
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 21 Apr 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?
Targeted Treatment Effect of 30% Decrease From Baseline to Day 28 in the Average Daily Pain Intensity (time frame: Day 28). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 21 Apr 2026.