Ask the Doc: Q & A with Edward Kasarskis, MD, PhD

Edward Kasarskis, M.D., Ph.D. is Director of the multidisciplinary ALS Center at the University of Kentucky Neuroscience Center in Lexington, Kentucky, professor in the Department of Neurology at the University of Kentucky, and Chief of Neurology at the VA Medical Center in Lexington KY. 

Dr. Kasarskis

Q: Given the excitement and promise being shown in stem cell research today, can you explain or summarize the current known types of stem cells that have been explored with ALS patients?

A: You ask an excellent and timely question. While there is indeed great potential in harnessing stem cells to solve problems in people with ALS, there is much work to be done before direct benefits will be possible. As people frequently say these days, “it’s complicated.”

For example, let me tell you a little bit about the only ALS trial so far in which neural stem cells are injected right into a patient’s spinal cord. It’s being overseen by the University of Michigan but based at Emory University, in Atlanta, and 15 patients to date have undergone the procedure while the FDA monitors its safety. Only one of the patients so far has shown improvement.

The clinical trial involves injecting between half a million and a million stem cells directly into the spine. Scientists think these cells may act to repair damaged nerve cells, hopefully stopping disease progression.

Inserting the stem cells is a delicate process. The spinal cord is a very perilous piece of real estate. Every step of the way is critical. The neurosurgeons in this project are skillful beyond belief.

Here’s what’s involved in this trial. The person with ALS goes to surgery, where physicians slice through skin and muscle, remove part of the lower-back (lumbar) spinal bone, and reveal a pulsing, white spinal cord about the width of a man’s index finger. That area is often used with people who are already losing strength in their legs; there’s less risk of losing capability. If that procedure is shown to be safe, at another time, physicians move the procedure up the spine, a place where they believe treatment may be most promising. But the risks in the upper spinal cord are greater because that area controls breathing, arm movements and leg movements. The cervical spinal cord is a very busy place.

The stem cells come from a biomedical firm called Neuralstem, and they are taken from the spine of a fetus that was aborted in 2000, and then cultured and recultured once again. Then they’re frozen until they’re used. After the cells are checked to make sure a large enough percentage are viable (still alive), they are injected into the substance of the spinal cord itself. To date, the clinical trial has cost about $2.5 million.

Still to come with this trial are months of data analysis. Then there are the decisions about whether the right kinds of stem cells have been chosen, how many should be injected, and where. There are so many practical questions to answer at every turn about whether the body may reject the stem cells as foreign bodies, as they often due with organ transplants. Do ALS patients receiving stem cells require immunosuppression, and if so, what drugs, what dose, and for how long? Could stem cells, with their propensity to propagate, turn malignant, as cancer cells do when then spread? And how will progress and effectiveness be measured?

In truth, it will most likely be decades before stem cell technology translates into routine treatment. But the research must continue. Breakthroughs could come from unexpected places but I hope that these comments put this important line of research into perspective.

If you would like to submit questions for a future Q & A, please send your questions to theexchange@alsa-national.org. Please understand that we won’t be able to address all questions and we won’t be able to respond to individuals personally.