ALS drug development guidances and trial guidelines: Consensus and opportunities for alignment.

The US Food and Drug Administration (FDA) developed a draft guidance for drug development in amyotrophic lateral sclerosis (ALS) that was issued in February 2018. The FDA draft guidance considered the recommendations developed by the ALS community that incorporated the views of a large group of clinical investigators, industry representatives, advocacy groups, patients, and caregivers. This external input from the ALS community reviewed the current state of clinical research in ALS, made suggestions over a wide range of drug development topics, and served as an educational tool to provide the agency with additional inputs about ALS, the state of the science, and the community's views on key topics. In parallel to this effort, there was an independent effort to revise and update the ALS Clinical Trial Guidelines. We discuss the areas of agreement of these 3 documents and the areas that provide opportunities to improve the efficiency of drug development in ALS. It is likely that further research into biomarkers, efficacy endpoints, and predictive algorithms will provide greater alignment among community stakeholders and increase clarity on drug development efforts going forward. Continued patient engagement and inclusion of patient experience data in every aspect of the drug development process will further facilitate the approval of new treatments.

The Right Therapy for Neurological Disorders: From Randomized Trials to Clinical Practice - Patients versus Investigator Expectations and Needs.

BACKGROUND: People living with amyotrophic lateral sclerosis (ALS) are now more proactive in making decisions about their treatment options, in particular with increased awareness through social media and the Internet. Together with increased awareness about the disease comes increased frustration that there is still only one Food and Drug Administration (FDA)-approved drug that modestly improves survival. SUMMARY: While efforts are underway to improve clinical trial design, patient involvement in trial design, clinical outcomes, and risk/benefit evaluations have become more recognized and will play a major role in the future success of clinical trials. This chapter addresses the perspective of people living with ALS and their perceptions of clinical trials. We describe various organizations and programs available that provide increased education and patient involvement. KEY MESSAGE: Stronger partnerships between those living with ALS, clinicians, government, nonprofit organizations, and regulatory agencies will significantly impact treatment development.

Modeling ALS with motor neurons derived from human induced pluripotent stem cells.

Directing the differentiation of induced pluripotent stem cells into motor neurons has allowed investigators to develop new models of amyotrophic lateral sclerosis (ALS). However, techniques vary between laboratories and the cells do not appear to mature into fully functional adult motor neurons. Here we discuss common developmental principles of both lower and upper motor neuron development that have led to specific derivation techniques. We then suggest how these motor neurons may be matured further either through direct expression or administration of specific factors or coculture approaches with other tissues. Ultimately, through a greater understanding of motor neuron biology, it will be possible to establish more reliable models of ALS. These in turn will have a greater chance of validating new drugs that may be effective for the disease.

Meeting report of the International Consortium of Stem Cell Networks' Workshop Towards Clinical Trials Using Stem Cells for Amyotrophic Lateral Sclerosis/Motor Neuron Disease.

The International Consortium of Stem Cell Networks' (ICSCN) Workshop Towards Clinical Trials Using Stem Cells for Amyotrophic Lateral Sclerosis (ALS)/Motor Neuron Disease (MND) was held on 24-25 January 2011. Twenty scientific talks addressed aspects of cell derivation and characterization; preclinical research and phased clinical trials involving stem cells; latest developments in induced pluripotent (iPS) cell technology; industry involvement and investment. Three moderated panel discussions focused on unregulated ALS/MND treatments, and the state of the art and barriers to future progress in using stem cells for ALS/MND. This review highlights the major insights that emanated from the workshop around the lessons learned and barriers to progress for using stem cells for understanding disease mechanism, drug discovery, and as therapy for ALS/MND. The full meeting report is only available in the online version of the journal. Please find this material with the following direct link to the article: http://www.informahealthcare.com/als/doi/10.3109/17482968.2011.590992 .

Therapeutic targets for amyotrophic lateral sclerosis: current treatments and prospects for more effective therapies.

Although amyotrophic lateral sclerosis (ALS) was described more than 130 years ago, the cause(s) of most cases of this adult motor neuron disease remains a mystery. With the discovery of mutations in one gene (Cu/Zn superoxide dismutase) as a primary cause of some forms of ALS, model systems have been developed that have helped us begin to understand mechanisms involved in motor neuron death and enabled testing of potential new therapies. Several other genes have been implicated as risk factors in motor neuron diseases, including neurofilaments, cytoplasmic dynein and dynactin, vascular endothelial growth factor, and angiogenin. With advances in the basic research of the disease, many hypotheses accounting for motor neuron death are being explored, including loss of trophic support, protein mishandling, mitochondrial dysfunction, excitotoxicity, axonal abnormalities and inflammation. Many of these mechanisms are the focus of research in other neurodegenerative disorders, such as Parkinson's, Alzheimer's and Huntington's disease.

Beta-lactam antibiotics offer neuroprotection by increasing glutamate transporter expression.

Glutamate is the principal excitatory neurotransmitter in the nervous system. Inactivation of synaptic glutamate is handled by the glutamate transporter GLT1 (also known as EAAT2; refs 1, 2), the physiologically dominant astroglial protein. In spite of its critical importance in normal and abnormal synaptic activity, no practical pharmaceutical can positively modulate this protein. Animal studies show that the protein is important for normal excitatory synaptic transmission, while its dysfunction is implicated in acute and chronic neurological disorders, including amyotrophic lateral sclerosis (ALS), stroke, brain tumours and epilepsy. Using a blinded screen of 1,040 FDA-approved drugs and nutritionals, we discovered that many beta-lactam antibiotics are potent stimulators of GLT1 expression. Furthermore, this action appears to be mediated through increased transcription of the GLT1 gene. beta-Lactams and various semi-synthetic derivatives are potent antibiotics that act to inhibit bacterial synthetic pathways. When delivered to animals, the beta-lactam ceftriaxone increased both brain expression of GLT1 and its biochemical and functional activity. Glutamate transporters are important in preventing glutamate neurotoxicity. Ceftriaxone was neuroprotective in vitro when used in models of ischaemic injury and motor neuron degeneration, both based in part on glutamate toxicity. When used in an animal model of the fatal disease ALS, the drug delayed loss of neurons and muscle strength, and increased mouse survival. Thus these studies provide a class of potential neurotherapeutics that act to modulate the expression of glutamate neurotransmitter transporters via gene activation.

Distinct patterns of tau-dependent process formation in mammalian cell lines.

Tau is a microtubule-associated protein involved in axonal elongation and central to the pathogenesis of a number of neurodegenerative conditions. To better establish the contribution of the cellular context to tau-dependent microtubule organization, we compared the phenotypes resulting from heterologous tau expression in different mammalian cell lines after disruption of the actin cytoskeleton. After cytochalasin D treatment, tau-expressing CHO cells display one or two long neurite-like extensions whereas cells transfected with MAP2c developed multiple shorter processes. By contrast, under the same conditions, tau-transfected PtK2 cells elaborate microtubule bundles forming numerous processes. These results suggest that cell-specific factors are involved in tau-dependent microtubule organization, a notion that could facilitate functional assessment of tau abnormalities associated with neurodegenerative disease.

Unraveling the mechanisms involved in motor neuron degeneration in ALS.

Although Charcot described amyotrophic lateral sclerosis (ALS) more than 130 years ago, the mechanism underlying the characteristic selective degeneration and death of motor neurons in this common adult motor neuron disease has remained a mystery. There is no effective remedy for this progressive, fatal disorder. Modern genetics has now identified mutations in one gene [Cu/Zn superoxide dismutase (SOD1)] as a primary cause and implicated others [encoding neurofilaments, cytoplasmic dynein and its processivity factor dynactin, and vascular endothelial growth factor (VEGF)] as contributors to, or causes of, motor neuron diseases. These insights have enabled development of model systems to test hypotheses of disease mechanism and potential therapies. Along with errors in the handling of synaptic glutamate and the potential excitotoxic response this provokes, these model systems highlight the involvement of nonneuronal cells in disease progression and provide new therapeutic strategies.