Clinical Trial Evaluates Safety and Efficacy of L-Arginine Supplementation in ALS Patients

Amyotrophic lateral sclerosis (ALS) is a progressive, fatal neurodegenerative disorder with no effective cure. Malnutrition significantly impacts the prognosis and overall outcomes of this disease, worsening the quality of life. A recent clinical trial aimed to evaluate the safety and efficacy of oral L-arginine hydrochloride supplementation in ALS patients, focusing on its impact on nutritional status and disease progression.

Study Design and Participants The trial was a single-center, single-arm, prospective, open-label study conducted from May 2023 to October 2023. A total of 29 patients were screened, with 20 enrolled to receive oral L-arginine hydrochloride. The majority of patients were concurrently using riluzole, and most had not undergone percutaneous endoscopic gastrostomy (PEG) or received noninvasive positive pressure ventilation (NPPV).

Safety Assessments During the study, 4 patients experienced treatment-emergent adverse events (TEAEs) within the first 45 days, and 6 patients experienced TEAEs within 90 days. The reported TEAEs included elevated creatinine kinase levels, liver function test abnormalities, glucose tolerance abnormalities, hyperammonemia, dysgeusia, and vasculitis. However, no serious adverse events or deaths related to the study drug were reported.

Effect of L-Arginine on Clinical Outcomes The study observed a modest decrease in body weight and BMI among participants. However, changes in muscle mass, fat mass, and the Mini Nutritional Assessment (MNA) score were significantly correlated with changes in body weight. Patients without weight loss presented increased L-arginine serum and urine levels, suggesting a potential role of L-arginine in weight maintenance.

Conclusion The trial demonstrated that oral L-arginine hydrochloride administered over 90 days was well tolerated in ALS patients, with no serious TEAEs or deaths related to the intervention. The maintenance of body weight, an indicator of nutritional status, was observed throughout the intervention period, correlating with the concentrations of L-arginine hydrochloride in the blood and urine. Future studies should consider randomized controlled trials to further explore the potential benefits of L-arginine supplementation in ALS patients.