Treatment options currently are limited for people suffering from secondary progressive multiple sclerosis. However, an Oregon Health and Science University (OHSU) pilot study suggests over-the-counter antioxidant lipoic acid holds promise for improving patients' lives.
The randomised double-blind study involved 51 participants who completed the two-year trial. Twenty-seven people were given a 1,200mg daily dose of lipoic acid, with the remaining 24 participants given a placebo. Researchers are using the findings from the pilot trial to design the expanded multi-site clinical trial to begin later this year in Portland and other sites that have yet to be finalised.
"These are high doses," said lead author Dr Rebecca Spain, an assistant professor of neurology in the OHSU School of Medicine. "And while it seems safe, we won't know whether it actually improves the lives of people with MS until we can replicate the results in the pilot study through a much bigger clinical trial. Fortunately, we're going to be able to answer that question with the participation of kind volunteers."
MS is a chronic condition that affects an estimated 2.3m people worldwide. In MS, the sheath covering nerve fibres in the brain and spinal cord becomes damaged, slowing or blocking electrical signals from the brain reaching the eyes, muscles and other parts of the body.
The major finding of the pilot study involved measuring the degree to which lipoic acid arrested the rate of whole brain atrophy, as measured through magnetic resonance imaging.
The study revealed a 68% improvement over the placebo in slowing the rate of whole brain atrophy in patients with secondary progressive MS. For the sake of comparison, a clinical trial involving the recent US Food and Drug Administration (FDA)-approved pharmaceutical Ocrevus showed an 18% improvement over a placebo in slowing the rate of whole brain atrophy for patients with primary progressive forms of the disease.
In addition, the pilot study suggested improved walking times and fewer falls among study participants who took a daily dose of lipoic acid compared with those who received the placebo. Researchers are eager to test those outcomes in the larger clinical trial.
A companion study measured the rate of absorption and clearance of lipoic acid through periodic blood tests of pilot study participants. The results will help to inform the design of additional clinical trials.
Lipoic acid was determined to be safe and well-tolerated by pilot study participants. Stomach upset was the most frequent side effect.
Abstract
Objective: To determine whether lipoic acid (LA), an endogenously produced antioxidant, slowed the whole-brain atrophy rate and was safe in secondary progressive MS (SPMS).
Methods: Patients with SPMS aged 40–70 years enrolled in a single center, 2-year, double-blind, randomized trial of daily oral 1,200 mg LA vs placebo. Primary outcome was change in annualized percent change brain volume (PCBV). Secondary outcomes were changes in rates of atrophy of segmented brain, spinal cord, and retinal substructures, disability, quality of life, and safety. Intention-to-treat analysis used linear mixed models.
Results: Participation occurred between May 2, 2011, and August 14, 2015. Study arms of LA (n = 27) and placebo (n = 24) were matched with mean age of 58.5 (SD 5.9) years, 61% women, mean disease duration of 29.6 (SD 9.5) years, and median Expanded Disability Status Score of 6.0 (interquartile range 1.75). After 2 years, the annualized PCBV was significantly less in the LA arm compared with placebo (−0.21 [standard error of the coefficient estimate (SEE) 0.14] vs −0.65 [SEE 0.10], 95% confidence interval [CI] 0.157–0.727, p = 0.002). Improved Timed 25-Foot Walk was almost but not significantly better in the LA than in the control group (−0.535 [SEE 0.358] vs 0.137 [SEE 0.247], 95% CI −1.37 to 0.03, p = 0.06). Significantly more gastrointestinal upset and fewer falls occurred in LA patients. Unexpected renal failure (n = 1) and glomerulonephritis (n = 1) occurred in the LA cohort. Compliance, measured by pill counts, was 87%.
Conclusions: LA demonstrated a 68% reduction in annualized PCBV and suggested a clinical benefit in SPMS while maintaining favorable safety, tolerability, and compliance over 2 years.
Authors
Rebecca Spain, Katherine Powers, Charles Murchison, Elizabeth Heriza, Kimberly Winges, Vijayshree Yadav, Michelle Cameron, Ed Kim, Fay Horak, Jack Simon, Dennis Bourdette
[link url="https://news.ohsu.edu/2017/07/03/patients-with-multiple-sclerosis-may-benefit-from-over-the-counter-therapy"]Oregon Health and Science University material[/link]
[link url="http://nn.neurology.org/content/4/5/e374.short#"]Neuroimmunology & Neuroinflammation abstract[/link]