Andrews, Howard A.

Abstract Introduction/Aims: Muscle cramps are a common and often disabling symptom in Amyotrophic Lateral Sclerosis (ALS), a devastating and incurable neurodegenerative disorder. To date, there are no medications specifically approved for the treatment of muscle cramps. Ameliorating muscle cramps in this patient population may sustain quality of life longer. A traditional Japanese medicine, shakuyakukanzoto (TJ-68) is widely prescribed in Japan for managing muscle cramps in a variety of conditions. The Japanese ALS Management Guideline mentions TJ-68 for difficult muscle cramps in ALS. Therefore, this clinical trial is designed to test the safety and efficacy of TJ-68 in participants with ALS reporting serious muscle cramps using a personalized N-of-1 approach. If successful, we can introduce TJ-68 for muscle cramps in ALS to Western medicine. Methods: With FDA-IND approval, we are conducting a two-site, double-blind, randomized personalized N-of-1 early clinical trial with TJ-68. At least 22 participants with ALS and daily muscle cramps will receive drug or placebo for 2 weeks (one treatment period) followed by a 1-week washout in a four-period cross-over design. While the primary objective is to evaluate the safety of TJ-68, the study was sized to detect a one-point shift on the Columbia Muscle Cramp Scale (MCS) item #5 with 85% power under a four-period crossover design.The secondary assessment includes the full MCS score, a Cramp Diary, Clinical Global Impression of Changes, Goal Attainment Scale, quality of life scale and ALS functional rating scale-revised (ALSFRS-R). Discussion: The study is underway. A personalized N-of-1 trial design is an efficient approach to testing medications that alleviate MCS in rare disorders. If TJ-68 proves safe and efficacious, we will work to introduce this product to Western medicine for treatment of patients with ALS and disabling muscle cramps. Trial Registration: This clinical trial has been registered with ClinicalTrials.gov (NCT04998305).