- Are there stem cell therapies available for ALS?
- How close are we? What do we know about ALS?
- What research is underway?
- Further reading on ALS
Are there stem cell therapies available for ALS?
To our knowledge, no stem cell therapy has received Health Canada or U.S. Food and Drug Administration approval for ALS treatment at this time. Patients who are researching their options may come across companies with Web sites or materials that say otherwise and offer fee-based stem cell treatments for curing this disease. Many of these claims are not supported by sound scientific evidence and patients considering these therapies are encouraged to review some of the links below before making crucial decisions about their treatment plan.
For the latest developments read our blog entries here.
For more about stem cell clinical trials for ALS click here. (For printed version: http://goo.gl/EJuP5)
How close are we? What do we know about ALS?
- Amyotrophic lateral sclerosis (ALS) is an incurable progressive neuromuscular disease. It also goes by the name of Lou Gehrig’s disease in North America and motor neurone disease in Australia and the United Kingdom.
- ALS attacks motor neurons, the specialized nerve cells that transmit electrical signals from the brain and spinal cord to the muscles throughout the body. In addition, the disease affects support cells in the brain creating a toxic environment for motor neurons.
- As ALS progresses, motor neurons slowly waste away and are unable to transmit the crucial signals that control eating, speaking, walking and even breathing. The entire body is affected, usually causing death within two to five years.
- ALS can be familial (linked to a genetic defect inherited among family members) or sporadic (randomly occurring with only a few accounts of genetic defects proven to play a role). Scientists agree that a complex interaction between genes and the environment contribute to causing this disease.
- There is no cure for ALS. Current treatments are only able to alleviate symptoms or delay the progression of disease for a few months.
How can stem cells play a part?
The best of all scenarios – preventing ALS by understanding its cause – may take many years. In the meantime, scientists are studying how stem cells could be used to treat this devastating disease. Stem cells have an unparalleled regenerative capacity and the flexibility to grow into hundreds of different types of cells, and also make factors that can protect cells. The ideal approach would take advantage of these characteristics to replenish the stores of motor neurons as well as other needed cell populations to protect motor neurons and to restore the microenvironment in the brain and spinal cord.
Are there lots of groups working on developing a stem cell therapy?
There are research teams around the globe actively studying how stem cells might be used to treat ALS. Their common goals are to identify which stem cells are best suited for the job, which signals are best to coax them into becoming motor neurons or other supporting cells, the large scale lab methods required for ramping up production, and the conditions required to grow neurons up to one metre — the length required to replace damaged neurons.
One of the most useful research contributions to date comes from using induced pluripotent stem cell or iPS technology. This revolutionary technology provides a way to reprogram adult cells from patients into embryonic-like stem cells, which can then be turned into patient-specific therapeutic cells. In a relatively short period of time, researchers have been able to use iPS technology to make cell lines of motor neurons and support cells, and these are proving to be invaluable for standardizing laboratory protocols, decoding the mechanisms of ALS, studying the different disease types, and testing and developing new drugs.
Stem cell research for ALS is moving along a number of different routes but only a few have thus far been successful enough to warrant Phase 1 and 2 clinical trials. These early trials are testing the safety and tolerability of using stem cells in ALS patients. Common to all the trials are the numerous challenges involved in transplantation: understanding how to ensure that the beneficial effects of the transplant can be localized to the area most in need, optimizing the number and spacing of the injections, controlling rejection in cases where the cells do not originate from the patient, and the high costs of clinical trials.
What research is underway?
Before basic stem cell research can be translated into the clinic for patients, it must first be rigorously tested and validated. For ALS, this includes transplanting stem cells into animal models to test if motor neuron function can be restored and to identify possible targets for future therapies. The main types of stem cells being investigated are fetal spinal cord stem cells, bone marrow stem cells (mesenchymal stem cells), neural stem cells (embryonic, fetal tissue or adult tissues), umbilical cord blood-derived stem cells and pluripotent stem cells (embryonic stem cells and iPS cells). In most cases, research is still at the pre-clinical stage, but successful experiments using fetal spinal cord stem cells and mesenchymal stem cells have reached the early phase clinical setting. Scientists are also looking at ways to stimulate the body’s own stem cells to produce new motor neurons, and ongoing studies are refining how to do this before prior to evaluating it at a multi-centre level.
The road to finding a stem cell therapy for ALS is paved with many challenges that will take time to overcome. But the wealth of information generated from labs around the globe is converging to help with the transition from basic research to the clinic. Although there is still much work to be done, the collaborative model for scientific discovery is lending momentum to developing stem cell therapies. Researchers are finding similarities among ALS, Alzheimer’s, Parkinson’s and Huntington’s and these clues are helping them to understand the cause of ALS. In addition, many research groups and drug development companies are forming partnerships to tackle more aggressive approaches for translating stem cell technology into possible ALS therapeutics.
Current research using fetal stem cells
The first FDA-approved human stem cell trial for ALS is a very small Phase 1 safety trial that involves transplanting up to 18 patients with stem cells from human fetal spinal cord tissue. This study led to the development of an innovative device that delivers stem cells directly into the lumbar region of the spinal cord of patients and buffers the movement of the spinal cord while the patient is breathing. This technology is an important advance for cell transplantation into the spinal cord. The trial is still unfolding, but the results are promising in terms of there being few adverse side effects. The hoped for outcome is the stem cells will make new neurons and/or supportive factors that will create an environment conducive to the survival of motor neurons in people with ALS. However, fetal tissue is used only in proof-of-principle experiments and is not regarded as a suitable source of stem cells for potential therapies. In recent years, scientists have found alternate sources of stem cells that circumvent the ethical issues. Two examples are umbilical cord blood and placenta, both of which are discarded at birth, and which contain a ready supply of fetal stem cells for research purposes.
Current research using bone marrow stem cells
The bone marrow contains a number of different types of stem cells, and one in particular, the mesenchymal stem cell, is proving to be quite useful. This stem cell lives in other sites around the body as well and can make a variety of different cell types. Pre-clinical studies in rodents have shown that these bone marrow stem cells, when injected into the brain and spinal cord, can grow into neurons and other support cells, and even become integrated into the animal’s spinal cord. Other studies with these stem cells have shown that they can delay progression of disease and improve the lifespan of the animals. Currently there is one small Phase 1 clinical trial underway to inject mesenchymal stem cells into the brain or spinal cord of early stage ALS patients. The hope is that these stem cells will grow into support cells that will make factors protecting motor neurons in the trial participants.
Current research using neural stem cells
Studies on how the normal adult brain continues to generate neurons throughout life and integrate them into existing circuits are of great value. In testing whether neural stem cells that normally reside in the spinal cord can be stimulated to restore damaged nervous tissue during ALS, it appears that they are capable of doing so to some extent but the numbers simply aren’t great enough to turn the tide of disease. However, researchers have found that human neural stem cells can be stimulated to produce support cells in high enough numbers and these protect motor neurons and prolong survival in rats. Even more encouraging is the fact that some of the cells are able to create a functional neural circuitry in the rats by making connections with motor neurons.
Further reading on ALS
Readers may wish to peruse the recommended sites and below for more information about ALS and the possible future applications of stem cells to treat this disease.
The ALS Society of Canada (www.als.ca)
The ALS Association (US) (www.alsa.org)
The Motor Neurone Disease Association (www.mndassociation.org)
The Packard Center (Johns Hopkins University) (www.alscenter.org)