Multiple Sclerosis Discovery -- Episode 20 with Dr. Jeffrey Cohen

[intro music]   Hello, and welcome to Episode Twenty of Multiple Sclerosis Discovery, the podcast of the MS Discovery Forum. I’m your host, Dan Keller.   This week’s podcast features an interview with Dr. Jeffery Cohen about two clinical trials. But to begin, here is a brief summary of some of the latest developments on the MS Discovery Forum at msdiscovery.org. Genome-wide association studies are raising more questions than they answer for multiple sclerosis, according to new research. As the number of risky genetic variants grew, researchers began to wonder if many of those variants would be found in the murky waters of “noncoding DNA,” which comprises about 98% of the human genome. Those fears were confirmed in a study published last month in the journal Nature. According to the report, almost 90% of the risk variants fell within the noncoding region and 60% were found in areas known as enhancers or switches. These areas manage gene activity, though researchers are far from fully understanding how they work. While genome-wide association studies have been helpful to researchers, this study highlights that they are just a first step towards a better understanding of MS and the human genome.   The International Progressive MS Alliance recently released a call for applications for their second round of grants. To go along with this announcement, Professor Alan Thompson, the head of the Alliance’s scientific steering committee, penned a post for our blog. In his post, he emphasizes the urgent need for more research into progressive MS. He notes that over one million people worldwide live with progressive MS, yet no specific treatments exist for this condition. You can read Professor Thompson’s post in the blog section of the News and Future directions tab at msdiscovery.org. To get more information about the grants from the Alliance, visit our “Funding Opportunities” section under the “Professional Resources” tab on our website.   In addition to the latest funding opportunity from the Progressive MS Alliance, we also recently posted a long list of funding opportunities from the National MS Society.   [transition music]   Now to the interview. Dr. Jeffrey Cohen is a neurologist and director of the Mellen Center for multiple sclerosis at the Cleveland Clinic. He spoke with MSDF about two clinical trials, one examining the clinical use of stem cells, the other about a generic version of glatiramer acetate, Copaxone.   Interviewer – Dan Keller First of all, what was the aim of the clinical stem cell trial and what phase was it done in?   Interviewee – Jeffrey Cohen So we now have 11 medications approved to treat multiple sclerosis. They are all effective in the early, relapsing remitting stage of the disease, but there is a major unmet need for treatments that repair damage and might be effective in progressive MS. Our main goal was to explore cell-based therapies to treat multiple sclerosis, specifically to test the feasibility and safety of administering so-called mesenchymal stem cells. This was a Phase I study of mesenchymal stem cells. These are stem cells that are present in many tissues of the body. We isolated them from bone marrow which is probably the version that is the best studied previously. We grew them in the laboratory to increase their numbers, and then readministered them intravenously. We were focusing primarily on safety, as I said. We had fairly intense monitoring for any complications. Thankfully, we saw none. We also looked in a very preliminary way for benefit using clinical measures, a variety of imaging approaches and immunologic measures.   MSDF What is the hypothesis here that they are doing? Do they actually get into the brain? You are infusing them IV. There is a blood-brain barrier, these are pretty big objects.   Dr. Cohen There are actually a large number of studies in the laboratory and in animals that suggest that these cells have a number of properties that we think would be of use in a disease like multiple sclerosis. First of all, they seem to modulate the immune response. They dampen down inflammation. But more importantly, they appear to be able to produce a wide range of soluble factors, growth factors and other substances that we think promote repair. We think of them as the delivery system for growth factors that promote repair. We don't think that they themselves develop into brain tissue but will become neuro-cells, but rather that they create a milieu that is conducive for the natural intrinsic repair processes to remyelinate or restore neurologic function. The other property that is potentially very advantageous is that they appear to be attracted to areas of tissue damage or inflammation. They appear to have the ability to migrate within tissues, and in fact to migrate from either the cerebral spinal fluid into the brain or from the blood into the nervous system. So we think we can take advantage of that by administering them intravenously.   MSDF Did you do dose-ranging here?   Dr. Cohen: We did not. One of the things we learned from this study is that there are a lot of unknowns about cell-based therapies. What the appropriate dose is? Whether multiple doses are needed? What is the best route of administration? Whether there are nuances as to how you grow the cells in culture? What characteristics you want to augment? Dose-ranging in particular is something that has been very difficult to do in the field, particularly for some of these cells that are grown in culture; you usually have the dose that you have. That has been an issue that we have struggled with as have others in the field.   MSDF How long did you follow these patients and what did you find?   Dr. Cohen We followed them for two months prior to infusion. That is the time during which their cells were being cultured, and then for six months after infusion. So very reassuringly there were no serious or severe adverse events. In fact, there were very little, if any, side effects. Patients were not immunosuppressed. They had no premedication. The only side effect was that the culture media contains a chemical called DSMO. Some patients got a garlic taste in their mouth. If they don't like Italian food, they didn't like that. We also looked in a preliminary way for evidence of benefit with the caveat that this study was not really designed to look for benefit. We used this as an opportunity to explore a variety of measures that might show tissue repair. We saw enticing improvement in some measures in some patients, but for patients as a group, there was no clear-cut evidence of benefit. We have to be very careful how we interpret these results.   MSDF Could you follow them in any way? Were they tagged or any other way that you know where they went?   Dr. Cohen No. That is another aspect of the cell therapy field that is getting a lot of attention. At the moment it is largely a black box. After we administer the cells, knowing whether they survive and where they go and how long they live there. That is another line of research besides pursuing further clinical trials of these cells is also to develop methods to track them within the body. There are some promising approaches that we are in the process of developing.   MSDF Now I take it these were not modified in any way, they were just cultured to multiply them?   Dr. Cohen There were some growth factors in the culture media, but they were from the regulatory point of view, not very manipulated. That is the terminology that is used. That is another area of debate is some of the specifics of the culture approach, whether we should add other factors that might change the properties of the cells. Whether it is okay for them to be frozen, which we do largely for convenience because then we can schedule the infusion. Or whether they should be taken fresh from the culture and administered. There are arguments for both approaches.   MSDF Many cells seem to hone right back to where they came from. Do these just go back to the bone marrow do you think, or do you think they actually went somewhere because that area needed repair?   Dr. Cohen There have been a few studies in some other conditions where these cells have been given. One of the interesting properties is that you can administer these cells from another person and they are not rejected. They become, I wouldn't say the standard, but a very common treatment for what is called graft-versus-host disease, which is a very severe complication of allogeneic bone marrow transplant where the transplanted immune system attacks the recipient's body. That is where the immunomodulatory effects of mesenchymal stem cells were first observed. There are, unfortunately, have been a couple of instances where MSCs that were from another person of a different gender, were administered to someone with graft-versus-host disease who unfortunately, subsequently died of GVH. In those cases, these cells were found in a range of tissues including bone marrow. Probably a more important obstacle is for after intravenous administration is the lung because that is where the blood goes from the veins. These cells probably collect in the lung initially and then percolate out into the tissues.   MSDF Do you have any concerns, any caveats about potential harms, limitations, from using this? Is it feasible on a large scale?   Dr. Cohen We took a very conservative approach with the idea that there are so many unknowns of cell-based therapies, including precedence in multiple sclerosis where therapies had a different effect than we anticipated. We thought it was appropriate to take a very careful systematic approach starting with a small safety study and then building from there. At least within the limitations of our study, meaning that it was relatively short, and relatively small, we saw no indications of any complications. Some of the hypothetical concerns would be cancer. Stem cells share some properties that are similar to cancer cells, or ectopic tissue formation. Stem cells have the natural ability to develop into almost any kind of tissue. At least, presumably they could go to one tissue and develop into another type of cell, so bone within the heart or something like that. We really saw no indication of that. There are really no examples of that in the literature, but because of those sorts of concerns, we took a very careful approach. We feel comfortable now moving on to a bigger program.    MSDF You had discussed some of the problems that arose using allogeneic cells. Just to clarify, this was using autologous cells?   Dr. Cohen Correct. These were cells from the patient themselves. There is still some debate in the field, which approach is better. Whether to take cells from the person themselves or whether to take cells from someone who does not have the disease that you are treating. That again is an issue that has not been settled. I think some of the cell tracking we were talking about earlier may help with that. Rather than answering all of these questions one trial at a time, we may be able to adjudicate some of these questions by seeing whether cells traffic more effectively.   MSDF Let’s shift to your other trial, the GATE trial using generic Copaxone. Is that available now and what was the point of the trial?   Dr. Cohen The purpose of this trial was potentially to have a generic version of one of the established multiple sclerosis drugs come available. The incentive would be that presumably because of the lower development costs, that the generic version would save money for payers and for patients. The trial we just completed was of a generic version of glatiramer acetate, Copaxone, one of the initial drugs approved to treat MS, a drug that we have a great deal of experience with. It has established efficacy and a known good safety profile. This study tested a generic version of that with the intent of showing that it had equivalent efficacy, in this case, as tested by MRI and had equivalent safety and tolerability.   MSDF These were all patients with relapsing, remitting MS? You had, what, about 735?   Dr. Cohen Correct. This was in a patient population with relapsing, remitting MS; the population for which Copaxone is approved.   MSDF What were the interventions, the test group?   Dr. Cohen There were three groups in this trial. One group was treated with generic glatiramer acetate. One group was treated with the brand Copaxone and then there was also a small placebo group to demonstrate what is called study assay sensitivity. The purpose of which was to show for the trial overall that the generic glatiramer acetate is equivalent to the brand-name, the reference drug as it is called, but also that within this trial with this population, that both drugs were effective.   MSDF Where was this done, and is that ethical?   Dr. Cohen One of the things we have encountered increasingly in developing multiple sclerosis drugs is that there are ethical and practical issues to including placebo groups. At this point it has become extremely difficult to include a placebo group in a large Phase III study that goes on for several years. In this case, this was a short trial, with the advantage of using MRI as the endpoint. It was conducted to some extent in North America, but primarily in Eastern Europe and other  countries where unfortunately, multiple sclerosis treatments are not as available.    MSDF What did you find?   Dr. Cohen The study was successful. It showed equivalent efficacy as measured by gadolinium-enhanced MRI, and also showed equivalent safety and tolerability as measured by adverse events and injection site tolerability.   MSDF What would this mean for patients if someone brought out a generic?   Dr. Cohen The hope would be, is that if this drug is approved, that it would be less expensive. Multiple sclerosis is an expensive disease to care for and a great part of that cost is medication costs. So the hope would be that this would be less expensive. The other caveat is that complicated molecules such as Copaxone are difficult to replicate. In addition to very extensive chemical and biophysical analyses, that is why a trial was conducted, because of the feeling that it would only be with clinical data that we could…we assure ourselves that this was in fact similar to Copaxone.   MSDF I would take it, that this would only apply to the generic you tested. I mean generics have a certain tolerance level margin compared to the approved brand, so not all generics are the same.   Dr. Cohen That is correct. It is actually quite tricky to develop a generic of a complicated molecule, either a complex mixture such as glatiramer acetate or a so-called biological like a monoclonal antibody. Each one has to be tested one at a time.   MSDF Anything important that we have missed, or to add?   Dr. Cohen This trial was designed with the assistance of, and discussions with EMA, the European Regulatory Agency. It has been somewhat more difficult in the United States. The FDA is still somewhat unclear on their policies and the procedures for testing complex generics and biosimilars. The status of this trial in the United States is still somewhat uncertain.   MSDF Very good. Thank you.   Dr. Cohen Thank you.   [transition music]   Thank you for listening to Episode Twenty of Multiple Sclerosis Discovery. This podcast was produced by the MS Discovery Forum, MSDF, the premier source of independent news and information on MS research. MSDF’s executive editor is Robert Finn. Msdiscovery.org is part of the non-profit Accelerated Cure Project for Multiple Sclerosis. Robert McBurney is our President and CEO, and Hollie Schmidt is vice president of scientific operations.    Msdiscovery.org aims to focus attention on what is known and not yet known about the causes of MS and related conditions, their pathological mechanisms, and potential ways to intervene. By communicating this information in a way that builds bridges among different disciplines, we hope to open new routes toward significant clinical advances.   We’re interested in your opinions. Please join the discussion on one of our online forums or send comments, criticisms, and suggestions to [email protected].   [outro music]