Neuralstem Pioneering Efforts In ALS

By Jason Napodano, CFA

Neuralstem, Inc. (NYSE MKT:CUR) has developed a technology that allows large-scale expansion of human neural stem cells ("hNSC") from all areas of the developing human brain and spinal cord. The company owns of has exclusive license to 25 patients and 29 patent applications pending worldwide in the field of regenerative medicine and cell therapy. Management is currently focusing the company's efforts on replacing damaged, malfunctioning, or dead neural cells with fully functional ones that may be useful in treating many central nervous system diseases and neurodegenerative disorders.

Neuralstems lead development program is for Amyotrophic Lateral Sclerosis ("ALS"), also known as Lou Gehrigs disease, named after the famous New York Yankee first baseman who was diagnosed with the disease in 1939, and passed in 1941 at the age of only 37.

ALS Background

ALS is a rapidly progressive neurodegenerative disease characterized by weakness, muscle atrophy and twitching, spasticity, dysarthria (difficulty speaking), dysphagia (difficulty swallowing), and respiratory compromise. The disease is almost always fatal, typically due to respiratory compromise or pneumonia, in two to four years. Initial symptoms of ALS include weakness and/or stiffness followed by muscle atrophy in the arms and legs. This is followed by slurred speech or difficulty swallowing, and loss of tongue mobility. Approximately a third of ALS patients also experience pseudobulbar affect (uncontrollable emotions). As the disease progresses, worsening dysphagia and respiratory failure leads to death. A small percentage of patients may also experience cognitive affects such as frontotemporal dementia and anxiety.

The vast majority (~95%) of cases are idiopathic, although there is a known hereditary factor that leads to familial ALS associated with a defect on the 21st chromosome that accounts for approximately 1.5% of all cases. There are also suspected environmental causative factors, including exposure to a dietary neurotoxin called BMAA and cyanobacteria, and use of pesticides. However, in all cases, the defining factor of ALS is rapid and progressive death of upper and lower motor neurons in the motor cortex of the brain, brain stem, and spinal cord. Prior to their destruction, motor neurons develop proteinaceous inclusions in their cell bodies and axons. This may be partly due to defects in protein degradation.

Treatment for ALS is limited, and as of today only riluzole, marketed by Sanofi-Aventis as Rilutek, has been found to improve survival to a modest extent (several months). Riluzole preferentially blocks TTX-sensitive sodium channels, which are associated with damaged neurons. This reduces influx of calcium ions and indirectly prevents stimulation of glutamate receptors. Together with direct glutamate receptor blockade, the effect of the neurotransmitter glutamate on motor neurons is greatly reduced. Riluzole does not reverse the damage already done to motor neurons, and people taking it must be monitored for liver damaged (about 10% incidence).

The remaining treatments for ALS are designed to relieve symptoms and improve quality of life. This supportive care includes a multidisciplinary approach that may include medications to reduce fatigue, control spasticity, reduce excess saliva and phlegm, limit sleep disturbances, reduce depression, and limit constipation. As noted above, median survival is two to four years. In the U.S., approximately 30,000 persons are currently living with ALS.

Neuralstems Approach For ALS

Neuralstem is seeking to treat the symptoms of ALS via transplantation of its hNSCs directly into the gray matter of the patients spinal cord. In ALS, motor neurons die, leading to paralysis. In preclinical animal work, Neuralstem cells both made synaptic contact with the host motor neurons and expressed neurotrophic growth factors, which are protective of cells.

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Neuralstem Pioneering Efforts In ALS