Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease, is a progressive neurodegenerative disorder characterized by the selective loss of upper and lower motor neurons in the brain and spinal cord[1]. This leads to progressive muscle weakness, paralysis, and ultimately respiratory failure, typically within 2-5 years of symptom onset[2]. Approximately 10% of cases are familial, with C9orf72, SOD1, FUS, and TARDBP being the most common genetic causes[3]. The remaining 90% are sporadic, with complex multifactorial etiology involving glutamate excitotoxicity, oxidative stress, mitochondrial dysfunction, neuroinflammation, and impaired RNA metabolism[4].
Riluzole, approved in 1995, remains the cornerstone of disease-modifying therapy for ALS[5]. The drug acts primarily by inhibiting glutamate release, reducing excitatory neurotransmission, and modulating sodium channels.
Clinical benefits: 2-3 month survival benefit, with more pronounced effects in patients with bulbar-onset disease[6]
Dosing: 50 mg twice daily, with monitoring of liver function
Side effects: Dizziness, fatigue, nausea
Edaravone, approved in 2017, is a free radical scavenger that reduces oxidative stress, a key pathological mechanism in ALS.
Clinical benefits: Reduced functional decline measured by ALSFRS-R score[7]
Administration: IV infusion for 14 days followed by 14-day drug-free periods
Side effects: Bruising, gait disturbance, headache
AMX0035 (sodium phenylbutyrate/taurursodiol), approved in 2022, targets mitochondrial dysfunction and endoplasmic reticulum stress.
Clinical benefits: Median 9.7 months survival benefit in CENTAUR trial[8]
Administration: Oral powder mixed with water
Side effects: Diarrhea, abdominal pain, nausea
Tofersen, approved in 2023, is an antisense oligonucleotide (ASO) therapy specifically targeting SOD1 gene mutations, which account for approximately 2% of all ALS cases[@millert2020].
Mechanism: Reduces SOD1 protein production through RNA splicing modification
Clinical outcomes: Significant reduction in SOD1 protein and neurofilament light chain (NfL) levels[9]
Administration: Intrathecal injection every 28 days
Requirement: Confirmed SOD1 mutation for treatment[fda2023]
Multidisciplinary ALS clinics improve survival and quality of life compared to standard care[11]. Core team includes:
C9orf72-Targeting Therapies: ASOs and small molecules targeting the C9orf72 hexanucleotide repeat expansion, the most common genetic cause of ALS, are in various trial stages[12].
FUS-Targeting Therapies: ASO therapies targeting FUS mutations are in development.
Neural stem cell transplantation trials have evaluated delivery to the spinal cord, showing preliminary safety and potential biological effects[13].
For comprehensive treatment protocols and detailed therapeutic approaches, see Amyotrophic Lateral Sclerosis Treatment.
ALS treatment has advanced significantly with four FDA-approved disease-modifying therapies (riluzole, edaravone, AMX0035, tofersen). Comprehensive management through multidisciplinary care remains essential for optimizing outcomes. Emerging gene therapies and stem cell approaches offer future promise for this devastating disease.
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Chio A, et al. Global epidemiology of amyotrophic lateral sclerosis: a systematic review of the literature. Neuroepidemiology. 2013. ↩︎
Renton AE, Chio A, Traynor BJ. State of play in ALS genetics. Nat Rev Neurol. 2014. ↩︎
Hardiman O, et al. Amyotrophic lateral sclerosis. Nat Rev Dis Primers. 2017. ↩︎
Lacomblez L, et al. Dose-ranging study of riluzole in amyotrophic lateral sclerosis. Lancet. 1996. ↩︎
Miller RG, et al. Riluzole for amyotrophic lateral sclerosis (ALS)/motor neuron disease (MND). Cochrane Database Syst Rev. 2012. ↩︎
Abe K, et al. Safety and efficacy of edaravone in well defined patients with amyotrophic lateral sclerosis: a randomised, double-blind, placebo-controlled trial. Lancet Neurol. 2017. ↩︎
Paganoni S, et al. Trial of Sodium Phenylbutyrate-Taurursodiol for Amyotrophic Lateral Sclerosis. N Engl J Med. 2020. ↩︎
Valeras MG, et al. Nucleate ASO therapy for SOD1-ALS: a randomized, double-blind, placebo-controlled study. Lancet Neurol. 2023. ↩︎
Bourke SC, et al. Effects of non-invasive ventilation on survival and quality of life in patients with ALS. Lancet. 2006. ↩︎
Traynor BJ, et al. Effect of a multidisciplinary ALS clinic on survival. Neurology. 2003. ↩︎
Liu Y, et al. C9orf72-targeted antisense oligonucleotide therapy for ALS. Nat Med. 2024. ↩︎
Glass JD, et al. Neural stem cell transplantation in patients with ALS: 24-month follow-up. Neurology. 2022. ↩︎