A Study to Evaluate the Safety and Tolerability of Arbaclofen Placarbil (XP19986) in Subjects With Acute Back Spasms

XenoPort

Status and phase: Completed; Phase 2

Conditions: Back Pain

Treatments: Drug: Arbaclofen placarbil, 40 mg; Drug: Arbaclofen placarbil, 20 mg; Drug: Arbaclofen placarbil, 30 mg; Drug: Placebo

Study type: Interventional

Funder types: Industry

Identifiers

NCT00817986

XP-B-083

Details and patient eligibility

About

The purpose of the study is to evaluate safety and tolerability of arbaclofen placarbil sustained release tablets taken every 12 hours compared to placebo in subjects with acute back spasms in the lumbar region.

Enrollment: 161 patients

Sex: All

Ages: 18 to 65 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. Acute moderate to severe muscle spasms in the lumbar region, as indicated by a minimum Visual Analog Scale pain severity score of 4.0 cm, beginning either:

   • within four days prior to screening for subjects who do not require a 24-hour washout

   Or

   • within three days for subjects who require a 24-hour washout

2. Willing to discontinue all analgesics (e.g. NSAIDS, COX-2 inhibitors, acetaminophen), aspirin >81 mg/day, short-acting muscle relaxants (i.e. carisoprodol, Soma®), and herbal remedies for pain at least 24 hours prior to first dose and to refrain from use during the study (cardio-protective doses of aspirin ≤ 81 mg /day are allowed).

Exclusion criteria

1. Clinically significant abnormal neurological history or examination at screening (excluding back spasm), including lumbar radicular symptoms, spinal stenosis, foot drop, herniated nucleus pulposus, or other structural defects

2. Subjects with back spasm related to major trauma to the region

3. Subjects with muscle spasms due to a work-related injury or subjects involved in any injury-related litigation

4. Subjects using any of the following medications at screening:

   • Opioids, both short- and long-acting including but not limited to: morphine, fentanyl patch, oxycodone, tramadol)
   • benzodiazepines, such as valium and lorazepam
   • cyclobenzaprine containing drugs (e.g., Flexeril, Amrix)
   • carisoprodol (e.g., Soma®) within 24 hours of screening

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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161 participants in 4 patient groups, including a placebo group

Arbaclofen placarbil 20 mg

Experimental group

Description:

Arbaclofen placarbil 20 mg, BID, for 14 days including the taper period.

Treatment:

Drug: Arbaclofen placarbil, 20 mg

Placebo for Arbaclofen placarbil

Placebo Comparator group

Description:

Placebo for 14 days

Treatment:

Drug: Placebo

Arbaclofen placarbil 30 mg

Experimental group

Description:

Arbaclofen placarbil 30 mg, BID, for 14 days including the taper period.

Treatment:

Drug: Arbaclofen placarbil, 30 mg

Arbaclofen placarbil 40 mg

Experimental group

Description:

Arbaclofen placarbil 40 mg, BID, for 14 days including the taper period.

Treatment:

Drug: Arbaclofen placarbil, 40 mg