This study will be the first trial to confirm the efficacy of mexiletine hydrochloride administration in SBMA patients.
Shinichiro Yamada, Nagoya University: ($50,000 per year for two years)
Most patients with SBMA experience cold exposure, a worsening of muscle movement under cold temperature, which is caused by muscle membrane hyperexcitability due to abnormal sodium current alteration. Based on the clinical and basic studies, we carried out a placebo-controlled, randomized, double-blind, multicenter, crossover exploratory clinical study of the efficacy and safety of mexiletine hydrochloride, a sodium channel blocker, in SBMA patients. ALSFRS-R which reflect comprehensive motor function and quantitative muscle strength in SBMA patients were tend to be improved in the mexiletine group. Therefore, we will prepare a confirmatory clinical trial with change of ALSFRS-R as the primary endpoint. This study will be the first trial to confirm the efficacy of mexiletine hydrochloride administration in SBMA patients.
In this proposal, we are also planning a biomarker study in parallel to support the results of the clinical trials. We will measure urine titin and serum neurofilament light chain (NfL) as a biomarker of motor neuron degeneration in the patients with SBMA and female carriers in SBMA that may reflect early pathophysiology of SBMA patients.
