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Corticobasal Syndrome (CBS)Phase 2PROFILNCT05983588

PROFIL Study to Investigate the Effect of GPB on NfL Levels in Patients With Corticobasal Syndrome (CBS)

A Phase 2 study testing RAVICTI 1.1 g/ml in people with Corticobasal Syndrome (CBS), run by Technical University of Munich at 2 sites in Germany.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Corticobasal syndrome (CBS) is a rapidly progressive neurodegenerative disorder with an average survival time of about 6-8 years after the first clinical manifestation. No potent symptomatic treatment is currently available. A disease-modifying therapy does not exist either. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Corticobasal Syndrome (CBS)
What is being tested?
RAVICTI 1.1 g/ml
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
32 participants
Where
2 sitesGermany
Study dates
12 Dec 2023to 13 Aug 2026
Phase
Phase 2
Are there results?
None posted in the registry

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

  • Age: ≥ 18 years
  • "clinical possible" or "clinical probable" CBS (Armstrong et al., Neurol-ogy, 2013 80;496-503) and patients with Progressive Supranuclear Palsy-CBS according to Höglinger et al. (Mov Disord. 2017 Jun;32(6):853-864)
  • No regular consumption of glycerol phenylbutyrate within the last 6 months prior to V1
  • Capable of thoroughly understanding all information given and giving full informed consent according to GCP
  • Capability and willingness to comply with the procedures of the clinical trial
  • Women of childbearing age must be non-lactating and surgically sterile or using a highly effective method of birth control and have a nega-tive pregnancy test. In case of using a hormonal contraception, the method must be supplemented with a barrier method (preferably male condom). Acceptable methods of birth control with a low failure rate i.e. less than 1% per year when used consistently and correct are such as implants, injectables, combined oral contraceptives, hormonal intrauterine devices (IUDs), sexual abstinence (defined as refraining from heterosexual intercourse during the clinical trial) or vasectomized partner. Unacceptable birth control methods are: periodic abstinence (calendar, symptothermal, post-ovulation methods), withdrawal (coitus interruptus), spermicides only and lactational amenorrhoea method (LAM). Female condom and male condom should not be used together.
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  • A stable regimen for at least 1 month prior to V1 and no foreseeable need to change the regimen throughout the 26 week treatment period for
  • drugs acting against Parkinsonism (e.g. Levodopa, Dopamine-Agonists, Amantadine and MAO-B-Inhibitors)
  • other CNS-active substances including e.g. antidepressants and antidementia drugs

Who cannot join

  • Neurodegenerative diseases other than CBS
  • Underlying Alzheimer's pathology as defined by positive β-amyloid-PET or reduced Aβ 1-42 in CSF
  • Participation in another clinical trial involving administration of an investigational medicinal product within 1 month or 5 half-lives of the investigational medicinal product, whichever is longer, prior to V1
  • Known hypersensitivity to glycerol phenylbutyrate or its further components, or to drugs with a similar chemical structure or to any of the components of the placebo
  • Treatment with valproic acid, haloperidol or probenecid
  • A physical or psychiatric condition (e.g. frontal lobe syndrome, psychotic disorder or major depression), which at the investigator's discretion may put the subject at risk, may confound the trial results or may interfere with the subject's participation in this clinical trial
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  • Persistent abuse of medication, drugs or alcohol
  • Current or planned pregnancy or breast-feeding in females
  • Other severe medical conditions upon the discretion of the investigator

Trial locations and contacts

2 sites in 1 country.

Germany2 sites

  • Klinikum der Universität München (KUM), Campus Großhadern, Klinik und Poliklinik für Neurologie & German Center for Neurodegenerative Diseases (DZNE), Department of Neurology

    Munich, Bavaria, 81377

  • Klinikum rechts der Isar Technische Universität München Klinik und Poliklinik für Neurologie & German Center for Neurodegenerative Diseases (DZNE), Department of Neurology

    Munich, Bavaria, 81377

Other trials in Germany

About this study

Official title: Double-blind, Randomised, Prospective, Placebo Controlled Parallel Group Phase II Study to Investigate the Effect of Glycerol Phenylbutyrate (GPB) on Neurofilament Light Chain (NfL) Levels in Patients With Corticobasal Syndrome (CBS)

Corticobasal syndrome (CBS) is a rapidly progressive neurodegenerative disorder with an average survival time of about 6-8 years after the first clinical manifestation. No potent symptomatic treatment is currently available. A disease-modifying therapy does not exist either. Neuroinflammation is key to the pathogenesis in neurodegenerative diseases with Tau- and/or AD-pathology. There is strong evidence that phenylbutyrate can modulate microglial function by enhancing their phagocytic activity, most likely by epigenetic mechanisms. So the main goal of this clinical trial is to study a potential disease-modifying effect of treatment with glycerol phenylbutyrate (GPB), which is a prodrug of phenylbutyric acid, for 26 weeks assessed by the levels of the biomarker neurofilament light chain (NfL) indicating disease progression in CBS. Given the aggressive nature of CBS, it is feasible to study effects of GPB on plasma NfL levels.

Being tested
RAVICTI 1.1 g/ml, Placebo
Medical subject headings
Corticobasal Degeneration

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • RAVICTI 1.1 g/mlDrug

    Also called Glycerol phenylbutyrate

    Duration of Treatment: 26 weeks, twice daily

    Dosage:

    • weeks 0 - 3: 3 ml/day (1,5ml - 0 - 1,5ml) (≙ 3,3 g glycerol phenylbutyrate/placebo)
    • weeks 4 - 26: 6 ml/day (3 ml - 0 - 3 ml) (≙ 6,6 g glycerol phenylbutyrate/placebo)

  • PlaceboDrug

    Duration of Treatment: 26 weeks, twice daily

    Dosage:

    • weeks 0 - 3: 3 ml/day (1,5ml - 0 - 1,5ml) (≙ 3,3 g glycerol phenylbutyrate/placebo)
    • weeks 4 - 26: 6 ml/day (3 ml - 0 - 3 ml) (≙ 6,6 g glycerol phenylbutyrate/placebo)
Study groups in NCT05983588
Study groupRoleWhat they receive
VerumExperimentalRAVICTI 1.1 g/ml oral liquid (glycerol phenylbutyrate (GPB)) Duration of Treatment: 26 weeks, twice daily
Receives: Drug: RAVICTI 1.1 g/ml
PlaceboPlacebo comparatorMatching Placebo, oral liquid Duration of Treatment: 26 weeks, twice daily
Receives: Drug: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. To assess the efficacy of glycerol phenylbutyrate vs. placebo in reducing the levels of neurofilament light chain (NfL) during 26 weeks of exposure to glycerol phenylbutyrate as well as safety and tolerability of glycerol phenylbutyrate in patients with

    To assess the efficacy of glycerol phenylbutyrate vs. placebo in reducing the levels of neurofilament light chain (NfL) during 26 weeks of exposure to glyc-erol phenylbutyrate as well as safety and tolerability of glycerol phenylbutyrate in patients with CBS.

    Measured: 26 weeks (between V1 and V3)

Secondary outcomes (9)

  1. To assess longitudinal changes in clinical scales

    To assess longitudinal changes in clinical scale: Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS Part III), min value 0- max value 132 (worse outcome)

    Measured: 26 weeks (between V1 and V3)

  2. To assess longitudinal changes in clinical scales

    To assess longitudinal changes in clinical scale: Progressive Supranuclear Palsy Rating Scale (PSP-RS), min value 0- max value 100 (worse outcome)

    Measured: 26 weeks (between V1 and V3)

  3. To assess longitudinal changes in clinical scales

    To assess longitudinal changes in clinical scale:Progressive Supranuclear Palsy Clinical Deficits Scale (PSP-CDS), min value 0- max value 21 (worse outcome)

    Measured: 26 weeks (between V1 and V3)

  4. To assess longitudinal changes in clinical scales

    To assess longitudinal changes in clinical scale: Cortical Basal ganglia Functional Scale (CBFS), min value 0- max value 124 (worse outcome)

    Measured: 26 weeks (between V1 and V3)

  5. To assess longitudinal changes in clinical scales

    To assess longitudinal changes in clinical scale: Dementia Apraxia Test (DATE), min value 0 (worse outcome) - max value 60

    Measured: 26 weeks (between V1 and V3)

  6. To assess longitudinal changes in clinical scales

    To assess longitudinal changes in clinical scale: MONTREAL COGNITIVE ASSESSMENT (MoCA), min value 0 (worse outcome) - max value 30

    Measured: 26 weeks (between V1 and V3)

  7. To assess longitudinal changes in clinical scales

    To assess longitudinal changes in clinical scale: SCHWAB AND ENGLAND ACTIVITIES OF DAILY LIVING SCALE (SEADL), min value 0 (worse outcome) - max value 100%

    Measured: 26 weeks (between V1 and V3)

  8. To assess longitudinal changes in clinical scales

    To assess longitudinal changes in clinical scale: Clinical Global Impression (CGI-s), min value 1- max value 7 (worse outcome)

    Measured: 26 weeks (between V1 and V3)

  9. To assess longitudinal changes in clinical scales

    To assess longitudinal changes in clinical scale: PSP RATING SCALE (PSP-QoL), min value 0- max value 180 (worse outcome)

    Measured: 26 weeks (between V1 and V3)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted9 Aug 2023
  2. Study start12 Dec 2023
  3. Primary completion13 Aug 2026
  4. Study completion13 Aug 2026

Resources

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
Double blind
Who is masked
Participant, Investigator
Enrolment
32 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05983588
Sponsor's protocol ID
PROFIL-2088-SIM-0032-I
Acronym
PROFIL
Status last verified
Aug 2026
First submitted
13 Jul 2023
Last updated
11 Sep 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Palleis C, Weidinger E, Maass S, Linke M, Brendel M, Stocklein S, Al Tawil A, Mansmann U, Teupser D, Borst T, Heimke-Brinck R, Hemmer B, Hoglinger GU, Bidner H, Simons M, Levin J. Study protocol: double-blind, randomized, prospective, placebo controlled parallel group phase II study to investigate the effect of glycerol phenylbutyrate (GPB) on neurofilament light chain (NfL) levels in patients with corticobasal syndrome (CBS). Neurol Res Pract. 2026 Jul 3;8(1):54. doi: 10.1186/s42466-026-00504-5.

    PubMed 42400090

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing RAVICTI 1.1 g/ml in people with Corticobasal Syndrome (CBS), run by Technical University of Munich at 2 sites in Germany.

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 9 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: finished, as of the sponsor's last update on 11 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites in Germany. 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?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

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?

To assess the efficacy of glycerol phenylbutyrate vs. placebo in reducing the levels of neurofilament light chain (NfL) during 26 weeks of exposure to glycerol phenylbutyrate as well as safety and tolerability of glycerol phenylbutyrate in patients with (time frame: 26 weeks (between V1 and V3)). 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 NCT05983588, 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 11 Sep 2026.

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