Try our beta test site
IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more...

Efficacy and Safety of Arbaclofen Placarbil in Subjects With Spasticity Due to Multiple Sclerosis

This study has been completed.
Information provided by (Responsible Party):
Indivior Inc. Identifier:
First received: May 22, 2011
Last updated: April 24, 2017
Last verified: April 2017
To evaluate the efficacy of three doses of XP19986 (arbaclofen placarbil) compared to placebo for the treatment of spasticity in subjects with multiple sclerosis (MS).

Condition Intervention Phase
Multiple Sclerosis
Drug: Arbaclofen placarbil 15 mg BID
Drug: Placebo
Drug: Arbaclofen placarbil 30 mg BID
Drug: Arbaclofen placarbil 45 mg BID
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Participant, Care Provider, Investigator, Outcomes Assessor
Primary Purpose: Treatment
Official Title: A Randomized, Double Blind, Placebo-Controlled Efficacy and Safety Study of Arbaclofen Placarbil in Subjects With Spasticity Due to Multiple Sclerosis

Resource links provided by NLM:

Further study details as provided by Indivior Inc.:

Primary Outcome Measures:
  • Change from Baseline in Maximum Ashworth Scale score (6 hour post-dose time point) [ Time Frame: 10-weeks ]
  • Patient Global Impression of Change (PGIC) score [ Time Frame: 10-weeks ]

Secondary Outcome Measures:
  • Change in the overall Modified PRISM score [ Time Frame: Weeks 4, 6, 10 ]
  • Change in weekly average severity of pain score associated with muscle spasm. [ Time Frame: Week 10 ]
  • Change in weekly average VAS score of sleep quality [ Time Frame: Week 10 ]

Enrollment: 228
Study Start Date: May 2011
Study Completion Date: February 2013
Primary Completion Date: February 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Arbaclofen placarbil 15 mg BID
Arbaclofen placarbil (XP19986 SR4) 15 mg every morning and every evening
Drug: Arbaclofen placarbil 15 mg BID
arbaclofen placarbil 15 mg BID
Other Name: XP19986 SR4
Active Comparator: Arbaclofen placarbil 30 mg BID
Arbaclofen placarbil (XP19986 SR4) 30 mg every morning and every evening
Drug: Arbaclofen placarbil 30 mg BID
arbaclofen placarbil 30 mg BID
Other Name: XP19986 SR4
Active Comparator: Arbaclofen placarbil 45 mg BID
Arbaclofen placarbil (XP19986 SR4) 45 mg every morning and every evening
Drug: Arbaclofen placarbil 45 mg BID
arbaclofen placarbil 45 mg BID
Other Name: XP19986 SR4
Placebo Comparator: Placebo
Placebo every morning and every evening
Drug: Placebo
Placebo for arbaclofen placarbil 15, 30 and 45 mg BID
Other Name: Sugar Pill


Ages Eligible for Study:   18 Years to 70 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Has multiple sclerosis (MS) based on Poser or McDonald Criteria (all subtypes of MS will be accepted, including relapsing remitting, primary or secondary progressive, if disease is stable per exclusion criteria).
  2. Maximum Ashworth Score Scale score of ≥ 2 in at least one of the following muscle groups on either side of the body: hip abductors/adductors, knee flexors/extensors, ankle flexors/extensors.
  3. Expanded Disability Status Scale (EDSS) rating between 3.0-8.0 inclusive.
  4. If a subject is on disease modifying MS treatment, the dosage, frequency, and route of administration must be stable for at least 30 days before screening and is expected to be stable throughout the study.
  5. Spasticity Disability Rating of 2 or higher at Baseline.
  6. Willing to discontinue and refrain from using for the duration of the study drugs for the treatment of spasticity or likely to affect spasticity (including, but not limited to, baclofen, tizanidine, diazepam, clonazepam, metaxalone, dantrolene, cyclobenzaprine, carisoprodol, clonidine, vigabatrin, valproic acid and cannabis).

Exclusion Criteria:

  1. Spasticity due to neurological disorder other than MS or other conditions that may confound the assessment of spasticity.
  2. Subject has clinically evident muscle contractures resulting in irreversible spasticity in lower extremities.
  3. Subjects who have suffered an acute relapse of MS (as determined by the Investigator) within 90 days prior to Screening, or have had more than 1 relapse within the year prior to Screening
  4. Botulinum toxin injection within 6 months of Screening or has current residual associated side effects at Screening.
  5. Subjects receiving concomitant medication from more than one of the following three drug classes: (Antiepileptic drugs, Tricyclic anti-depressants and Opioids)
  6. Subjects on the following medications, at doses above the specified limits, are excluded if they cannot maintain a level within these limits

    • Gabapentin ≤ 1800 mg per day or pregabalin ≤ 150 mg per day
    • Amitriptyline ≤ 75 mg per day or nortriptyline ≤ 75 mg per day
    • Opioids ≤ 30 mg morphine equivalents per day.
  7. Evidence of unstable or severe systemic illness, including but not limited to: Cardiovascular disease (e.g., chronic ventricular arrhythmia, unstable angina or CHF), respiratory disease (e.g., sleep apnea, COPD requiring oxygen therapy or hospitalization in last year), endocrine disease, hepatic disease (e.g., chronic active hepatitis), renal disease, or immunodeficiency.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01359566

  Show 28 Study Locations
Sponsors and Collaborators
Indivior Inc.
Study Director: Study Director Indivior Inc.
  More Information

Responsible Party: Indivior Inc. Identifier: NCT01359566     History of Changes
Obsolete Identifiers: NCT01360489
Other Study ID Numbers: XP-B-089
Study First Received: May 22, 2011
Last Updated: April 24, 2017
Individual Participant Data  
Plan to Share IPD: No

Additional relevant MeSH terms:
Multiple Sclerosis
Pathologic Processes
Demyelinating Autoimmune Diseases, CNS
Autoimmune Diseases of the Nervous System
Nervous System Diseases
Demyelinating Diseases
Autoimmune Diseases
Immune System Diseases
Arbaclofen placarbil
Muscle Relaxants, Central
Physiological Effects of Drugs
Neuromuscular Agents
Peripheral Nervous System Agents
GABA-B Receptor Agonists
GABA Agonists
GABA Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action processed this record on May 25, 2017