Research News
Drug Being Studied for SPMS
Pirfenidone is a new oral drug that is being studied for the treatment of secondary-progressive MS (SPMS). Study findings from the most recent of three small trials with pirfenidone were presented in early October at the American Neurological Association's Annual Meeting in Toronto, Ontario, Canada. The purpose of the one-year, single-center, phase II clinical trial was to evaluate the drug's effectiveness and continued safety.
Developed by the biopharmaceutical company Marnac, pirfenidone is an anti-fibrosis agent that was initially tested for the scarring of lung tissue, which occurs in pulmonary fibrosis. It also inhibits the production of Tumor Necrosis Factor-alpha (TNF-a), a tissue hormone produced by cells as part of an autoimmune response. This cytokine is thought to damage or destroy normal brain cells, so inhibiting the production of TNF-a may protect myelin (the layer of insulation surrounding the nerves) and ultimately protect the nerves.
In addition to SPMS and pulmonary fibrosis, pirfenidone is in trials for preserving kidney function in those with diabetes and to slow the growth of tumors involving nerves (neurofibromas). Pirfenidone has not yet been studied for individuals with relapsing-remitting MS (RRMS); and a few individuals with primary-progressive MS (PPMS) were included in an earlier study for safety.
According to Marnac, this drug does not have the toxicity risks that other treatments for SPMS may present, while offering the convenience of oral administration.
The SPMS study was small, enrolling only 43 individuals. Slightly more than one-third of the participants dropped out before the one-year study was complete, with the number of those leaving the placebo group being slightly greater than those leaving from the treatment group.
The 27 individuals who completed the study were evaluated at regular intervals using the Scripps Neurological Rating Scale (SNRS), the Expanded Disability Status Scale (EDSS), and MRI scans. While the drug company reported an improvement in mean neurological scores for individuals in the treatment group as measured by the SNRS, Marnac did not comment in their press release about the other measures of treatment efficacy, i.e., the EDSS and MRI scans. These latter two are considered important in the evaluation of MS disease activity. Those involved with the treatment of MS await analysis of these other outcomes.
Given the small number of participants and short duration of this study, results are not conclusive. The preliminary test results, however, are encouraging enough that Marnac may sponsor a larger, multi-center trial with pirfenidone and SPMS. The good news is that new drugs continue to be studied for all types of MS. MSAA will keep readers updated as more definitive studies with pirfenidone are conducted and outcomes are published in peer-reviewed journals.
