In the last years research has pointed out potential mechanisms of pathogenesis in ALS including lack of degradation of abnormally accumulated proteins inside motor neurons, and an unbalanced function of the immune system leading to the prevalence of a neurotoxic function over neuroprotection. These two mechanisms contribute to ALS progression hence representing important therapeutic targets to modify disease expression.

With a phase II clinical trial the investigators aim to study the biological response in ALS treated with Rapamycin, to obtain predictive information for a larger study.

Eight Italian Centres will enroll 63 patients; treatment will be double blinded to patients and physicians, and will last 18 weeks.Follow up will be carried out for 36 months (total duration: 54 weeks).

This is a phase II randomized, double-blind, placebo-controlled, multicenter clinical trial for people with ALS.

The aim is to study the biological and clinical effect of Rapamycin (in two different doses) in addition to Riluzole on ALS patients through comparison with patients treated with Riluzole and placebo.

Rapamycin has been shown to enhance proteins degradation, and this has been associated with beneficial effects in models of neurodegeneration. Its immunomodulatory effects are also well established, notably the ability to suppress inflammatory neurotoxic responses mediated by T cells. As ALS is characterized by heterogeneous pathology and protein accumulation, some patients may respond to therapies that accelerate the clearance of abnormally accumulated proteic aggregates, while suppressing neurotoxic immune elements.

Subjects will be enrolled in 3 groups of 21 subjects; treatment will be double blinded to patients and physicians, and will last 18 weeks. Active treatment will include oral Rapamycin at different doses: Rapamycin 1mg/m2/day or Rapamycin 2mg/m2/day. Rapamycin will be administered at fast, in the morning, once a day. Rapamycin levels will be measured (HPLC) to avoid toxicity (>15 ng/ml), but treating neurologists will have no access to blood laboratory data. Dosages will be adjusted accordingly and sham adjustments will be done in the placebo Group too. Post-treatment follow up will be 36 weeks. Globally the study will lasts 24 months. To monitor adverse events, examination and routine laboratory work (cell count, lipids and protein profile, kidney and liver function, C reactive protein) will be performed before taking Rapamycin/placebo. Non-routine laboratory studies include quantification and characterization of Tregs, lymphocytes phenotype, mTOR (mammilian target of rapamycin) downstream pathway activation in peripheral blood mononuclear cells (PBMC), inflammasome components in PBMC and proinflammatory cytokine production in monocytes, peripheral biomarkers. Cerebrospinal fluid (CSF) will be taken at baseline and at week 18 to measure neurofilaments and to dose Rapamycin to understand whether sufficient levels of Rapamycin can be found in the central nervous system (CNS).

Inclusion criteria:

• Patient diagnosed with a laboratory supported , clinically "probable" or "definite" amyotrophic lateral sclerosis according to the Revised El Escorial criteria (Brooks, 2000)
• Familial or sporadic ALS
• Female or male patients aged between 18 and 75 years old
• Disease duration from symptoms onset no longer than 18 months at the screening visit
• Patient treated with a stable dose of Riluzole (100 mg/day) for at least 30 days prior to screening
• Patients with a weight > 50 kg and a BMI ≥18
• Patient with a FVC ≥ 70 % predicted normal value for gender, height, and age at the screening visit
• Patient able and willing to comply with study procedures as per protocol
• Patient able to understand, and capable of providing informed consent at screening visit prior to any protocol-specific procedures
• Use of effective contraception both for males and females

Exclusion Criteria:

• Prior use of Sirolimus
• Prior allergy/sensitivity to Sirolimus or macrolides
• Any medical disorder that would make immunosuppression contraindicated, including but not limited to, acute infections requiring antibiotics, patients with known diagnosis of HIV, tuberculosis, hepatitis B or C infection or history of malignancy
• Severe comorbidities (heart, renal, liver failure), autoimmune diseases or any type of interstitial lung disease
• White blood cells<4,000/mm³, platelets count<100,000/mm³, hematocrit<30%
• Patient who underwent non invasive ventilation, tracheotomy and /or gastrostomy
• Women who are pregnant or breastfeeding
• Participation in pharmacological studies within the last 30 days before screening
• Patients with known superoxide dismutase 1 (SOD1) mutation or with familial ALS and a family member carrying SOD1 mutation.

treatment double blinded to patients and physicians