ALS, also known as Lou Gehrig’s disease, is a rapidly progressive, fatal neurological disease, striking people between the age of 40 to 60. ALS occurs when the brain and spinal cord nerve cells, which control voluntary muscle movement, deteriorate. Patients experience rapid muscle atrophy, difficulty in breathing/swallowing and eventual paralysis of the lower body. Death is always the outcome for ALS victims and life expectancy is very short once diagnosis is made: 2 to 5 years. During the disease progression, victims maintain normal sensory and cognitive abilities, which makes suffering particularly difficult, as they are aware of their surroundings and the changes happening in their body.
At any given time, it is estimated that there are approximately 400,000 people suffering from ALS. Although the number seems quite low, it is due to the high fatality of the disease, and thus the very small living patient population. It is projected that every 90 minutes, someone is diagnosed with ALS. This disease is not selective and can affect people of all nationalities and gender. The majority of ALS (80-90%) is not hereditary and has no known cause or risk factor.
There is currently no approved drug that stops the disease progression or prolongs significantly the life of ALS sufferers. Rilutek, which was approved by the FDA to treat ALS, provides only an additional three-moth life extension. Given the severity of the disease and the lack of therapeutic options, there is a clear need to develop and make available to patients a new medication to treat ALS. In this endeavor, ReMedys is working on two innovative approaches to bring relief to ALS patients.
Drug Repurposing for ALS
Targeting micro RNA processing – rebalancing normal neuronal activity
Altered expression of micro RNAs (miRNAs, see graphic) is increasingly recognized as a possible cause of neurodegenerative diseases1. It is believed to play roles in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis (ALS) and Huntington's disease. miRNAs are abundantly expressed in the nervous system and play important roles in its regulation. Research has shown that in ALS patient tissues and animal models of the disease deregulation of miRNAs are implicated in the pathology.
In this ALS project, we are developing a drug (RMC001) that has been shown to reinvigorate miRNA processing. The drug on which RMC001 is based has been approved for other indications in many countries. In our repositioning effort of RMC001 we will take full advantage of the extensive safety and human pharmacology information available.
- If appropriate funding can be obtained we expect that RMC001 can be tested and validated in ALS patients for the first time in the 3rd or 4th quarter of 2014.
Goodall EF, Heath PR, Bandmann O, Kirby J and Shaw PJ (2013) Neuronal dark matter: the emerging role of microRNAs in neurodegeneration. Front. Cell. Neurosci. 7:178. doi: 10.3389/fncel.2013.00178
Gene Therapy Treatment for ALS
There are two types of ALS, familial and sporadic. Familial forms of ALS account for approximately 10% of ALS cases and a number of causative mutant genes have been identified. The most commonly found familial form of ALS is associated with missense mutations in the SOD1 gene and these mutant forms have been shown to possess toxic properties.
The gene therapy approach we are developing aims at specifically suppressing the mutant SOD1 mRNA, thus avoiding the expression of the toxic gene product. To achieve the elimination of the mutant RNA, we use a strategy that nature uses itself to regulate specific RNA levels: micro RNA. The micro RNA cognate of the mutant SOD1 gene is packaged into a viral vector (adeno associated virus (AAV)) and delivered into the cerebrospinal fluid by injection. The virus will dock to the cells and deliver the genetic material to the cell to produce the miRNA that will block expression of mutant SOD1. Animal models of ALS have shown very promising results for this approach.
Gene therapy is again very much in the focus of innovative and targeted treatment options for many diseases following the approval of Glybera (for lipoprotein lipase deficiency) in Europe in 20122. This approved therapy also uses AAV as the vector for delivering the corrective genetic coding material.
This highly innovative project will require extensive preclinical and toxicological evaluation as well as very controlled and sophisticated manufacturing of the therapeutic agent before it can be tested in humans. If the required funding can be obtained we expect that the first human dose for clinical testing could be delivered end of 2015.
Gene therapy using an adenovirus vector. A new gene is inserted into a cell using an adenovirus. If the treatment is successful, the delivered gene will provide the genetic code to produce the corrective therapeutic agent locally in the cell, such as micro RNA or protein (Modified from Wikipedia: http://en.wikipedia.org/wiki/Gene_therapy).
2 Laura M. Bryant, Devin M. Christopher, April R. Giles, Christian Hinderer, Jesse L. Rodriguez, Jenessa B. Smith, Elizabeth A. Traxler, Josh Tycko, Adam P. Wojno, and James M. Wilson. Human Gene Therapy Clinical Development. June 2013, 24(2): 55-64. doi:10.1089/humc.2013.087. Online at http://online.liebertpub.com/doi/full/10.1089/humc.2013.087