Huntington ChoreaPhase 2NCT05475483
Efficacy and Safety on SOM3355 in Huntington's Disease Chorea
A Phase 2 study testing SOM3355 200 mg capsules and SOM3355 300 mg capsules in people with Huntington Chorea, run by SOM Innovation Biotech SA at 23 sites in 7 countries.
Trial summary
Phase IIb, randomized, double-blind, placebo-controlled study in parallel groups assessing the efficacy and safety of two doses of SOM3355 in patients suffering from Huntington's Disease with choreic movements. Read more about this study
- Who is it for?
- Ages 21 years and older
- Conditions the study is for
- Huntington Chorea
- What is being tested?
- SOM3355 200 mg capsules and SOM3355 300 mg capsules
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 139 participants
- Where
- 23 sitesin 7 countries
- Study dates
- 2 Aug 2022to 15 Jul 2024
- 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 21 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Inclusion Criteria: Males or females ≥21 years old, a diagnosis of Huntington's Disease determined by a movement disorders expert and confirmed by a number of HTT gene CAG repeats ≥36, a UHDRS® Total maximal chorea (TMC) score ≥10, and a UHDRS® Total Functional Capacity (TFC) ≥7.
Exclusion Criteria: Onset of HD symptoms prior to age of 21 years (juvenile forms of HD), HD patients presenting rigid akinesia, and use of other VMAT2 inhibitors such as tetrabenazine, deutetrabenazine, or valbenazine, or other antichoreic treatment such as any neuroleptic, or amantadine, memantine, riluzole.
Trial locations and contacts
23 sites in 7 countries.
23 sites in 7 countries
France5 sites
Centre Hospitalier Universitaire Angers
Angers
CHU Hôpital Henri Mondor (APHP)
Créteil
Hôpital Roger Salengro - CHU Lille
Lille
Hopital de Hautepierre
Strasbourg
Hôpital Purpan - CHU Toulouse
Toulouse
Germany4 sites
Charité - Universitätsmedizin Berlin
Berlin
George Huntington Institut
Münster
Kbo-Isar-Amper-Klinikum Taufkirchen
Taufkirchen
Hospital of University of Ulm
Ulm
Italy4 sites
IRCCS Istituto delle Scienze Neurologiche di Bologna
Bologna
Azienda Ospedaliera Universitaria Federico II
Naples
IRCCS Casa Sollievo della Sofferenza
Roma
Sant'Andrea University Hospital
Roma
Spain4 sites
Hospital de la Santa Creu i Sant Pau
Barcelona
Hospital Universitario de Cruces
Bilbao
Hospital Universitario de Burgos
Burgos
Hospital Ramón y Cajal
Madrid
United Kingdom3 sites
Cambridge University Hospitals NHS Foundation Trust Addenbrooke's Hospital
Cambridge
NIHR Wellcome Trust Manchester Clinical Research Facility
Manchester
Oxford University Hospitals NHS Foundation Trust
Oxford
Poland2 sites
Krakowska Akademia Neurologii Sp. z o.o.
Krakow
Indywidualna Praktyka Lekarska Daniel Zielonka
Poznan
About this study
Official title: Phase IIb, Randomized, Double-blind, Placebo-controlled Study in Parallel Groups Assessing the Efficacy and Safety of Two Doses of SOM3355 in Patients Suffering From Huntington's Disease With Choreic Movements
Phase IIb, randomized, double-blind, placebo-controlled study in parallel groups assessing the efficacy and safety of two doses of SOM3355 in patients suffering from Huntington's Disease with choreic movements.
- Conditions
- Huntington Chorea
- Being tested
- Placebo capsules, SOM3355 200 mg capsules, SOM3355 300 mg capsules
- Keywords
- Huntington, Chorea, SOM3355
- Medical subject headings
- Huntington Disease, Chorea
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Placebo capsulesDrug
Treatment was blind for the whole duration of the study.
SOM3355 200 mg capsulesDrug
Also called Bevantolol hydrochloride
Treatment was blind for the whole duration of the study.
SOM3355 300 mg capsulesDrug
Also called Bevantolol hydrochloride
Treatment was blind for the whole duration of the study.
| Study group | Role | What they receive |
|---|---|---|
| Placebo | Placebo comparator | Placebo capsules were administered twice daily (BID) for at least 9 weeks at maintenance dose. Receives: Drug: Placebo capsules |
| SOM3355 400 mg/day | Experimental | SOM3355 200 mg capsules were administered twice daily (BID) for at least 9 weeks at maintenance dose. Receives: Drug: SOM3355 200 mg capsules |
| SOM3355 600 mg/day | Experimental | SOM3355 300 mg capsules were administered twice daily (BID) for at least 8 weeks at maintenance dose. Receives: Drug: SOM3355 300 mg capsules |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Total Maximal Chorea (TMC) Score of the UHDRS® for Subjects Not Taking Neuroleptics During the Trial (mITT - N=122)
Pre-defined analysis of the primary efficacy endpoint (change in TMC score from baseline to the end of maintenance dose) performed with the 122 subjects of the mITT not taking neuroleptics during the trial.
The TMC is part of the motor assessment of the Unified Huntington's Disease Rating Scale (UHDRS) and measures chorea in 7 different body parts, including the face, oral-buccal-lingual region, trunk, and each limb independently. The TMC score is the sum of the individual scores, ranging from 0 to 28. A decrease in TMC scores indicates improvement in chorea symptoms.
Measured: From baseline to end of maintenance dose (10 weeks of treatment).
Secondary outcomes (2)
Change in the Clinical Global Impression (CGI) (mITT - N=139)
The key secondary endpoint was the Clinical Global Impression of Change (CGI-C) at Visit 5 (week 10). The key secondary efficacy analysis was conducted on the mITT Population, including 139 subjects. Subjects with a score of 1 (Very much improved), 2 (Much improved), or 3 (Minimally improved) were defined as "Improved", and patients with a score of 4 (No change), 5 (Worse), 6 (Much worse), and 7 (Very much worse) were defined as "Not Improved".
Measured: From baseline to end of maintenance dose (10 weeks of treatment).
Change in the Patient Global Impression (PGI) (mITT - N=139)
Another relevant secondary endpoint was the Patient Global Impression of Change (PGI-C) at Visit 5 (week 10). The efficacy analysis was conducted on the mITT Population, including 139 subjects. Subjects with a score of 1 (Very much improved), 2 (Much improved), or 3 (Minimally improved) were defined as "Improved", and patients with a score of 4 (No change), 5 (Worse), 6 (Much worse), and 7 (Very much worse) were defined as "Not Improved".
Measured: From baseline to end of maintenance dose (10 weeks of treatment).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Jul 2022
- Study start2 Aug 2022
- Primary completion25 Jun 2024
- Study completion15 Jul 2024
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 (1)Papers the sponsor has linked to this study.
- Other trials for Huntington ChoreaStudies 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
- 139 participants (actual)
Sponsor and investigators
- Lead sponsor
- SOM Innovation Biotech SA
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05475483
- Sponsor's protocol ID
- SOMCT03
- Other IDs
- 2021-003453-28
- Status last verified
- Aug 2025
- First submitted
- 22 Jul 2022
- Last updated
- 28 Aug 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Kulisevsky J, Craufurd D, Lewerenz J, Scaglione C, Squitieri F, Youssov K, Burgunder JM, Ferre A, Panigone S, Medori R. Safety and efficacy of SOM3355 in patients with Huntington's disease (SOMCT03): a phase 2b, randomised, placebo-controlled, multicentre, dose-ranging study. EClinicalMedicine. 2026 Sep 28;100:104234. doi: 10.1016/j.eclinm.2026.104234. eCollection 2026 Oct.
PubMed 42857615
Study at a glance
From the registry record, last updated by the sponsor on 28 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Phase IIb, Randomized, Double-blind, Placebo-controlled Study in Parallel Groups Assessing the Efficacy and Safety of Two Doses of SOM3355 in Patients Suffering From Huntington's Disease With Choreic Movements
- ClinicalTrials.gov ID
- NCT05475483
- Acronym / sponsor ID
- SOMCT03
- Conditions
- Huntington Chorea
- Keywords
- Huntington, Chorea, SOM3355
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 139 participants (actual)
- Lead sponsor
- SOM Innovation Biotech SAIndustry (pharma, biotech, devices)
- Study start
- 2 Aug 2022 (actual)
- Primary completion
- 25 Jun 2024 (actual)
- Study completion
- 15 Jul 2024 (actual)
- First posted
- 27 Jul 2022 (actual)
- Results
- Posted 28 Aug 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Phase IIb, randomized, double-blind, placebo-controlled study in parallel groups assessing the efficacy and safety of two doses of SOM3355 in patients suffering from Huntington's Disease with choreic movements.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Placebo | Placebo comparator | Drug: Placebo capsulesPlacebo capsules were administered twice daily (BID) for at least 9 weeks at maintenance dose. |
| SOM3355 400 mg/day | Experimental | Drug: SOM3355 200 mg capsulesSOM3355 200 mg capsules were administered twice daily (BID) for at least 9 weeks at maintenance dose. |
| SOM3355 600 mg/day | Experimental | Drug: SOM3355 300 mg capsulesSOM3355 300 mg capsules were administered twice daily (BID) for at least 8 weeks at maintenance dose. |
Who may qualify
- Ages
- 21 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
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 |
|---|---|---|
| Placebo capsulesTreatment was blind for the whole duration of the study. | Drug | Placebo |
| SOM3355 200 mg capsulesAlso: Bevantolol hydrochlorideTreatment was blind for the whole duration of the study. | Drug | SOM3355 400 mg/day |
| SOM3355 300 mg capsulesAlso: Bevantolol hydrochlorideTreatment was blind for the whole duration of the study. | Drug | SOM3355 600 mg/day |
Primary outcome
Change in Total Maximal Chorea (TMC) Score of the UHDRS® for Subjects Not Taking Neuroleptics During the Trial (mITT - N=122)
Time frame: From baseline to end of maintenance dose (10 weeks of treatment).
Pre-defined analysis of the primary efficacy endpoint (change in TMC score from baseline to the end of maintenance dose) performed with the 122 subjects of the mITT not taking neuroleptics during the trial. The TMC is part of the motor assessment of the Unified Huntington's Disease Rating Scale (UHDRS) and measures chorea in 7 different body parts, including the face, oral-buccal-lingual region, trunk, and each limb independently. The TMC score is the sum of the individual scores, ranging from 0 to 28. A decrease in TMC scores indicates improvement in chorea symptoms.
2 secondary outcomes
Change in the Clinical Global Impression (CGI) (mITT - N=139)
Time frame: From baseline to end of maintenance dose (10 weeks of treatment).
Change in the Patient Global Impression (PGI) (mITT - N=139)
Time frame: From baseline to end of maintenance dose (10 weeks of treatment).
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Aug 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 42857615Kulisevsky J, Craufurd D, Lewerenz J, Scaglione C, Squitieri F, Youssov K, Burgunder JM, Ferre A, Panigone S, Medori R. Safety and efficacy of SOM3355 in patients with Huntington's disease (SOMCT03): a phase 2b, randomised, placebo-controlled, multicentre, dose-ranging study. EClinicalMedicine. 2026 Sep 28;100:104234. doi: 10.1016/j.eclinm.2026.104234. eCollection 2026 Oct.
- SOM Biotech websiteLink provided by the sponsor.
- Individual participant dataSharing planned: Undecided
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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.
The record lists no contact. Use the official record to reach the sponsor.
23 sites in 7 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing SOM3355 200 mg capsules and SOM3355 300 mg capsules in people with Huntington Chorea, run by SOM Innovation Biotech SA at 23 sites in 7 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
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 28 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 23 sites in France, Germany, Italy, Spain, United Kingdom and 2 more countries. 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 28 Aug 2025). 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?
Change in Total Maximal Chorea (TMC) Score of the UHDRS® for Subjects Not Taking Neuroleptics During the Trial (mITT - N=122) (time frame: From baseline to end of maintenance dose (10 weeks of treatment).). 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 NCT05475483, 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 28 Aug 2025.