Summary: Investigators nationwide are recruiting 400 people with secondary-progressive MS orrelapsing-remitting MS to compare the effectiveness of three doses of the oral drug AVP-923 (Nuedexta®, dextromethorphan hydrobromide and quinidine sulfate, Avanir Pharmaceuticals) or inactive placebo in reducing central neuropathic pain. The study is funded by Avanir Pharmaceuticals.
Rationale: Studies suggest that half of people with MS experience pain. There are two types of chronic pain experienced by people with MS: central neuropathic pain (caused by nerve damage) and non-neuropathic pain (caused by muscle spasms or contractions). Central neuropathic pain is often described as burning, stabbing, and shooting pain in the legs and arms; and numbness, tingling, prickly, or “pins and needles” sensations. The purpose of this study is to evaluate the investigational use of AVP-923 to determine if it reduces central neuropathic pain experienced by those with MS.
AVP-923 is a patented, orally-administered combination of dextromethorphan and an enzyme inhibitor known as quinidine. Quinidine slows down the breakdown of dextromethorphan in the body, which results in a sustained elevation of dextromethorphan in the brain. Marketed as Nuedexta®, the drug is approved to treat pseudobulbar affect (uncontrolled episodes of crying and or laughing that are disconnected from or out of proportion to what the person is feeling at the time) in people with MS and other neurological diseases. Based on its biological activity within the central nervous system, the drug is being evaluated for its potential impact against pain as well.
Eligibility and Details: Participants should be ages 18 to 85, with a diagnosis of relapsing-remitting or secondary-progressive MS, and a clinical history or symptoms of central neuropathic pain. Because AVP-923 may cause serious side effects including changes in heart rhythm, participants with certain cardiac conditions are excluded from the study. For more details about enrollment criteria, please contact the study site nearest you.
Participants are being randomly assigned to receive one of three AVP-923 doses or inactive placebo (taken as one capsule twice a day) for 12 weeks. Participants have 75% chance (3 out of 4) of receiving AVP-923 and 25% chance (1 out of 4) or receiving placebo. The primary goal of the study is to determine whether pain symptoms are reduced, by using the Pain Rating Scale. Secondary endpoints include improvements in clinical scales that measure fatigue, MS disease activity, sleep quality and depression.
Contact: To learn more about the enrollment criteria for this study, and to find out if you are eligible to participate, please contact the study site nearest you. The list of recruiting sites can be found on clinicaltrials.gov.
Nuedexta is a registered trademark of Avanir Pharmaceuticals, Inc.
