Slow ALS Symptoms Dr.’s Q&A
What happens in ALS, and what does it do to a person?
Dr. Rosenfeld: ALS, or amyotrophic lateral sclerosis, is a motor neuron disease, which means nerve cells are dying. Motor nerve cells normally live in the brain and in the spinal cord. There are two populations of motor nerve cells. In the brain, the motor nerve cells initiate and coordinate regulate movement. In the spinal cord, those nerve cells communicate with muscles to make the movements. ALS patients have both difficulty and the inability to initiate, coordinate or regulate movement.
Does it affect a certain age group?
Dr. Rosenfeld: The spectrum is really extended. We commonly see patients in their 40s, 50s and some in their 60s. However, with better treatments and larger clinics, we’re seeing patients from a much greater spectrum. In our clinic, we have patients in their 20s, 30s and 40s, as well, and we do have one or two patients in their 80s.
What is the drug you are administering, and how does it help ALS patients?
Dr. Rosenfeld: The drug is called BDNF, which stands for brain derived neurotrophic factor. Neurotrophic factors are growth factors that promote both the survival and hopefully the sprouting of healthy nerve cells. In the case of BDNF, what we’re hoping to do is keep nerve cells alive that would otherwise be vulnerable to cell death during the course of the ALS. BDNF has one of many neurotrophic factor proteins that have been identified over the years.
BDNF was studied previously in a different type of trial in ALS patients, where it was injected under the skin. In that trial, it didn’t appear to be significantly beneficial. The idea then came about that if BDNF were delivered directly in the spinal fluid, we might have a better effect.
How does the new pump work?
Dr. Rosenfeld: In this study, BDNF is administered through an intrafecal pump, which is implanted in the abdomen. The pump is about the size of a hockey puck. A very thin, flexible catheter comes out of the pump and goes underneath the skin around the person’s flank. The end of that catheter has tiny holes in it, and it is inserted between two vertebraes into the spinal fluid for continuous delivery of the drug. The pump is active 24 hours a day. Patients return to us on a monthly basis, when we drain the reservoir of the pump and then refill it with fresh BDNF.
Does the volume of the pump depend on their condition?
Dr. Rosenfeld: No. Everybody is getting the same amount delivered. The actual volume of BDNF a person gets in one day is very small, only about a tenth of a milliliter. The pump itself, however, holds 18 milliliters, which is significantly more. So every month, we wind up draining the pump and replenishing more fresh solution than they’ve actually used.
How long does the pump stay implanted?
Dr. Rosenfeld: This pump is designed to stay in the patient for life. Most commonly, the patients are not at all aware the pump is in there. It doesn’t cause discomfort to them.
Have you seen any side effects in this study?
Dr. Rosenfeld: There are different side effects in different patients, and it’s just too early to tell whether there’s been a systematic effect. We don’t know who in the trial receives the study drug and who receives the placebo, and we won’t know for some time.
Have you seen any change in your patients?
Dr. Rosenfeld: I’m not seeing the progression that was expected. When I see a person progressing perhaps slower than I would have expected, I optimistically hope it’s the treatment we offer them. I have seen scenarios like that with this drug, although that’s just antidotal. The only proof will be in time.
What do you hope BDNF will do?
Dr. Rosenfeld: What we’re hoping for is that the disease progression will be slowed and perhaps even stopped. Once that happens, it might allow for the surviving nerve cells to compensate for the function that was lost in some of the degenerative nerve cells. That’s our most optimistic projection.
Can you predict the progression rate of ALS?
Dr. Rosenfeld: In ALS, the past usually predicts the future. If a person has had a particularly slow progression over 12 months, I can generally count on them to continue a particularly slow progression over the next 12 months. Rarely does it pick up speed and then slow down or stop. It usually establishes a rate of progression.
What would happen if somebody who was using BDNF stopped?
Dr. Rosenfeld: I have no expectation that interrupting the drug would be harmful. Of course, the purpose of our study is to administer the drug and see if there’s a benefit. The safety profile of the drug so far is quite favorable.
What is the future of ALS treatments?
Dr. Rosenfeld: ALS research is probably among the most exciting fields in all of neurology as well as in neuroscience, mostly because of the number of discoveries and advances both from the laboratory and in the clinic. In the history of ALS, there has never been a time where as many advances, as many people are involved, as many hypotheses are being tested as they are right now. Here in our center, we have an unusually large number of trials running. We currently are following patients in nine different experimental protocols for ALS alone. Just by virtue of having so many different hypotheses being tested at the same time, it is very exciting.
Source: Ivanhoe @2000
