Phase II/III multicenter, randomized, double-blind, placebo-controlled trial on acetyl-L-carnitine (ALCAR) in subjects living with amyotrophic lateral sclerosis (ALS). Primary study aim: The clinical objective consists of assessing the efficacy of ALCAR (two different dosages will be tested: 1.5g/day and 3g/day) on the progression of functional disability (loss of self-sufficiency), as measured by the ALSFRS-R scale. Secondary study aims: 1. The effect of ALCAR treatment on different clinical aspects: functional decline as measured by ALSFRS-R total score; the decline of forced vital capacity (FVC); quality of life as measured by ALSAQ-40 scale; cognitive function as measured by Edinburgh Cognitive and Behavioural ALS Screen (ECAS) scale; survival (being alive and without tracheostomy). 2. To measure the effects of ALCAR treatment on disease biomarkers potentially involved in the drug's mechanisms of action. These include PGC-1 alpha, 3-nitrotyrosine (3-NT), acetyl cyclophilin A (acetyl-PPIA), neurofilament light chain (NFL), creatine kinase (CK), Musclin/osteocrin, MyomiRNA (MiR-206), Uric acid, Matrix metalloproteinase-9 (MMP-9), Monocyte Chemoattractant Protein-1 (MCP-1), 4-Hydroxynonenal (HNE). 3. The tolerability and safety of ALCAR treatment by identifying unexpected adverse events.

Study population: 246 subjects will be enrolled on one Australian and ten Italian ALS sites.

Inclusion criteria: subjects aged 18+ years with a diagnosis of ALS according to Gold Coast Criteria; disease duration <24 months; satisfactory bulbar and spinal function (self-sufficiency evaluated by a score 3+ on the ALSFRS-R for swallowing, cutting food and handling utensils, and walking); satisfactory respiratory function (FVC ≥80% of predicted); documented progression of symptoms as measured by the ALSFRS-R scale. Disease progression rate (DFS) must be>= 0.33. DFS =(48- ALSFRS-R at screening)/months from onset to screening, treatment with Riluzole in the last four weeks. Exclusion criteria: antecedent polio infection; other motor neuron disease; involvement of other systems possibly determining a functional impairment; other severe clinical conditions; unwillingness or inability to take riluzole; previous use of ALCAR for any reason; inability to understand and comply with the study requirements, and to give written informed consent personally or via their legally authorized representative.

All eligible participants will be randomized to receive ALCAR (1,5 or 3 g/day) or placebo in addition to riluzole 50 mg b.i.d. Permuted block (with a block size of 6), 1:1:1 centralized randomization scheme will be used. The overall treatment duration will be 48 weeks. After enrolment, each participant will be followed up until death. Eligible subjects will be seen after 4, 12, 24, 36 and 48 weeks. At each visit, a general assessment will be made, including vital signs, body mass index (BMI), neurological examination (including quantitative and qualitative evaluation of the motor system), comorbidity, concomitant treatments and adverse events. Blood samples will be collected at baseline -Day 1 (randomization)-, 4, 12, 24, 36 and 48 weeks to test biomarkers. Functional disability will be assessed at each visit using the ALS-FRS-R scale. The respiratory function will be assessed using a spirometer to measure FVC before starting treatment (baseline visit) and at 4, 12, 24, 36 and 48 weeks. Cognitive function will be evaluated at baseline, weeks 24 and 48, using ECAS scale. Health-related quality of life, measured by the ALSAQ-40, will be tested at baseline, 24 and 48 weeks. Compliance will be tested by the local investigators, counting unused packages at each follow-up visit. Pre-planned statistical analyses will be done on Intention-to-treat and Per-protocol (PP) populations. The statistical plan will include descriptive statistics and a comparison of the proportions of self-sufficient participants at week 48 using the chi-square or Fisher's exact test for the primary endpoint. Secondary endpoints measured by numerical scores obtained from clinical scales will be analyzed using repeated measures mixed models, while biomarkers using repeated measures ANOVA. Time-to-event endpoints, such as survival and the probability of remaining self-sufficient over 48 weeks, will be analyzed with Kaplan-Meier curves. The number of adverse events and serious adverse events after 48 weeks will be compared between treatment arms.

Inclusion Criteria:

1. Age 18+;

2. ALS diagnosis according to the Gold Coast Criteria;

3. Disease duration < 24 months from symptom onset, as indicated by limb weakness or bulbar symptoms, at the randomization/baseline visit*;

4. Self-sufficiency [Satisfactory bulbar and spinal function (score 3+ on the ALSFRS-R for swallowing, cutting food and handling utensils, and walking)];

5. Satisfactory respiratory function (FVC ≥80% of predicted);

6. Documented progression of symptoms as measured by the ALSFRS-R scale. Disease progression rate (DFS) must be>= 0.33. DFS =(48- ALSFRS-R at screening)/months from onset to screening.

7. Ability to understand and comply with the study requirements;

8. Ability to give written informed consent personally or, as an alternative, via a legally authorized representative;

9. Treatment with riluzole 50 mg twice/day for at least 4 weeks prior to randomization visit;

10. Intact cognitive function, again determined by the Principal Investigator.

    • The qualifying first symptoms of ALS are limited to manifestations of weakness in extremity, bulbar, or respiratory muscles. Cramps, fasciculations, or fatigue should not be taken in isolation as a first symptom of ALS.

Exclusion Criteria:

1. Antecedent polio infection or other active infection;
2. Motor neuron disease (MND) other than ALS;
3. Involvement of other systems possibly determining a functional impairment (as measured by the endpoints) for the entire duration of the study;
4. Other severe clinical conditions (e.g., cardiovascular disorders, neoplasms) with an impact on survival or functional disability in the next 12 months;
5. Previous use of ALCAR for any reason;
6. Poor compliance with previous treatments;
7. Other experimental treatments in the three months prior to the screening visit (if a subject is receiving another experimental drug, a 3-month wash-out period before participating in the present clinical trial will be required);
8. Women who are lactating or able to become pregnant (e.g. who are not post-menopausal, surgically sterile, or using inadequate birth control) and men unable to practice contraception for the duration of the treatment and three months after its completion;
9. Inability to understand and comply with the study requirements;
10. Unwillingness or inability to take riluzole.