Methodological Quality of Clinical Trials in Amyotrophic Lateral Sclerosis: A systematic Review.

Background: More than 200 clinical trials have been performed worldwide in ALS so far, but no agents with substantial efficacy on disease progression have been found. Objective: To describe the methodological quality of all clinical trials performed in ALS and published before December 31, 2022. Methods: We conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta Analyses. Results: 213 trials were included. 47.4% manuscripts described preclinical study evaluation, with a positive effect in all. 67.6% of trials were conducted with a parallel-arm design, while 12.7% were cross-over studies; 77% were randomized, while in 5.6% historical-controls were used for comparison. 70% of trials were double blind. Participant inclusion allowed forced vital capacity (or corresponding slow vital capacity)<50% in 15% cases, between 55-65% in 21.6%, between 70-80% in 14.1% reports, and 49.3% of the evaluated manuscripts did not provide a minimum value for respiratory capacity at inclusion. Disease duration was <  6-months in 6 studies, 7-36 months in 68, 37-60 months in 24, 8 trials requested more than 1-month of disease duration, while in 107 reports a disease duration was not described. Dropout rate was ≥20% in 30.5% trials, while it was not reported for 8.5% . Conclusion: The methodological quality of the included studies was highly variable. Major issues to be addressed in future ALS clinical trials include: the requirement for standard animal toxicology and phase I studies, the resource-intensive nature of phase II-III studies, adequate study methodology and design, a good results reporting.

Retrospective observational study on the use of acetyl-L-carnitine in ALS.

ALCAR (Acetyl-L-carnitine) is a donor of acetyl groups and increases the intracellular levels of carnitine, the primary transporter of fatty acids across the mitochondrial membranes. In vivo studies showed that ALCAR decrease oxidative stress markers and pro-inflammatory cytokines. In a previous double-blind placebo-controlled phase II trial showed positive effects on self-sufficiency (defined as a score of 3+ on the ALSFRS-R items for swallowing, cutting food and handling utensils, and walking) ALSFRS-R total score and FVC. We conducted an observational, retrospective, multicentre, case-control study to provide additional data on the effects of ALCAR in subjects with ALS in Italy. Subjects treated with ALCAR 1.5 g/day or 3 g/day were included and matched with not treated subjects by sex, age at diagnosis, site of onset, and time from diagnosis to baseline, (45 subjects per group). ALCAR 3 g/day vs not treated: 22 not treated subjects (48.9%) were still alive at 24 months after baseline, compared to 23 (51.1%) treated subjects (adj. OR 1.18, 95% CI 0.46-3.02). No statistically significant differences were detected in ALSFRS nor FVC nor self-sufficiency. ALCAR 1.5 g/day vs not treated: 22 not treated subjects (48.9%) were still alive at 24 months after baseline, compared to 32 (71.1%) treated subjects (adj. OR 0.27, 95% CI 0.10-0.71). For ALSFRS-R, a mean slope of - 1.0 was observed in treated subjects compared to - 1.4 in those not treated (p = 0.0575). No statistically significant difference was detected in the FVC nor self-sufficiency. Additional evidence should be provided to confirm the efficacy of the drug and provide a rationale for the dosage.