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Host – Dan Keller
Hello, and welcome to Episode Forty-One 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 Diego Cadavid, who discusses trials of anti-LINGO-1 in MS. But first, a few updates on the latest developments at MSDF.
Our Drug-Development Pipeline includes continually updated information on 44 investigational agents for MS. During the past week, we added 3 new trials and 11 other pieces of information. The drugs with important additions are dalfampridine, fingolimod, glatiramer acetate, interferon beta-1a, interferon beta-1b, naltrexone, and natalizumab. To find information on all 44 compounds, visit msdiscovery.org and click first on Research Resources and then on Drug-Development Pipeline.
According to our curated list of the latest scientific articles related to MS, 54 such articles were published last week. To see last week’s list, go to msdiscovery.org and click on Papers. We selected two of those papers as Editors’ Picks. One is a meta-analysis of mortality studies showing that excess mortality in MS relative to the general population has not changed over the past 50 years. In the other Editor’s Pick, Jagannadha Avasarala points out that 20% of patients who present with a symptom consistent with a diagnosis of clinically isolated syndrome do not meet radiological criteria on brain MRIs. Dr. Avasarala has contributed an essay to MSDF in which he discusses the consequences of this finding. To see his essay, go to msdiscovery.org and click first on News and Future Directions and then on Essays and Opinions.
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Now to the interview. Dr. Diego Cadavid works at Biogen Idec, a pharmaceutical company involved in MS therapeutics. Our executive editor, Bob Finn, caught up with him in Washington D.C. at the annual meeting of the American Academy of Neurology, where Dr. Cadavid presented results of a phase 2 trial of an anti-LINGO-1 antibody called BIIB033 in which the antibody appears to promote myelin repair in the human brain.
Interviewer – Robert Finn
Dr. Cadavid, welcome.
Interviewee – Diego Cadavid
Thank you, Bob, for having us.
MSDF
First, what is anti-LINGO-1, and what does it target?
Dr. Cadavid
Anti-LINGO-1 is an investigation and treatment for a myelin repair. It targets a protein called LINGO-1 expressed in the myelin forming cells that normally inhibits the production of myelin. By blocking LINGO-1, we believe healthy cells actually make myelin and at the same time help patients with demyelinating diseases like MS.
MSDF
Tell me more about LINGO-1. Why this target makes sense in multiple sclerosis.
Dr. Cadavid
Yeah, so LINGO-1 is an inhibitor of myelination. So MS is a demyelinating disease, and it's well established that the majority of patients once they lose myelin they actually are not capable of repairing it. And the question in the field has been why? It's becoming clear that it's not because of a lack of cells; the myelin forming cells are there, but they're not making myelin. So one of the leading hypothesis is that there is a blockade of the ability of these cells to make the myelin. Biogen – more than 10 years ago – was looking for a molecules that could mediate that inhibition, and that's when they found LINGO-1. And through a series of experiments in animal models and in vitro, they showed that when you block LINGO-1 these cells actually differentiate and make myelin. Here we are more than 10 years later reporting the first results of an efficacy trial of anti-LINGO in humans. That's the RENEW study in acute optic neuritis.
MSDF
So tell me about the use of optic neuritis sort of as a model of MS.
Dr. Cadavid
Yes, we chose acute optic neuritis as the first efficacy trial because, first of all, acute optic neuritis is how many of them, as patients, actually initially present. They're healthy, living in the community, and so then they lose vision in one eye due to acute optic neuritis. In fact, during their lifetime, most MS patients will develop acute optic neuritis, so it is very relevant to MS. But also because it's the one part of the brain that is readily accessible. Through the pupil, we can actually image the neurons of the optic nerve. And using electrophysiology and something called visual evoked potentials, we can very accurately measure the function of this neuronal pathway. So it is not only relevant to MS, we have really good tools to investigate not only the disease but what anti-LINGO-1 may be doing to help the patients.
MSDF
But are there indications that anti-LINGO-1 has affects more centrally than the optic nerve?
Dr. Cadavid
So the optic nerve – we call it a nerve, but it is really not a nerve – it's a part of the brain. So anti-LINGO-1 is actually a central molecule. What we mean? It's really expressed only in neurons and in the myelin forming cells; it's not expressed outside of the central nervous system. So all the effects of anti-LINGO-1 are believed to occur centrally.
MSDF
Where is anti-LINGO-1 in the development process?
Dr. Cadavid
We are in the middle of drug development process, Bob, I assume you're asking me. We are in the middle of phase 2. We just finished the first of the two phase 2 trials called RENEW. These are results we are communicating at the academy this year. We believe the RENEW trial results showed efficacy on the primary endpoint: recovery of latency of the visually evoked potential. And we believe this is the first evidence that blocking LINGO-1, in fact, is leading to remyelination in the human brain, first episode of acute optic neuritis. So it's only approved for biology. At the same time, we are running a larger study in MS patients both relapsing-remitting and secondary-progressive. It is a longer trial, 22 months. That trial is fully enroll, ongoing, and we are looking forward to the results next year. The results of both trials will inform on the next steps.
MSDF
Is that a phase 2 trial, as well?
Dr. Cadavid
Correct. It's the MS trial; it's called SYNERGY, and it's a phase 2 trial. It is dose ranging. Unlike RENEW in which we only tested one dose, in the MS trial – SYNERGY – we are testing several doses.
MSDF
How is it administered?
Dr. Cadavid
It is a monoclonal antibody given every four weeks by an intravenous infusion.
MSDF
So you said that the results of this larger phase 2 trial will be available next year. Assuming that those results are favorable, what's the next step after that?
Dr. Cadavid
The final phase of drug development is what we call phase 3, which is when we actually run definite trials where the primary endpoint it's some meaningful clinical endpoint. For example, improvement in disability, slowing of disease worsening. So those phase 3 trials are usually longer and larger, and if the primary endpoints are met and the safety and tolerability is adequate, we file hoping for drug approval and to make this therapy available to patients.
MSDF
Four or five years?
Dr. Cadavid
Phase 3 trials are usually longer, and we don't know until we're there. But yeah, these are a longer part of the drug development process.
MSDF
Now assuming that the clinical trials do pan out – and maybe it's a little bit too early to ask this question, but I'm going to ask it anyway – how will anti-LINGO-1 be used? Is it going to be used early in the disease, late in the disease? The way other DMTs are used now continuously or to respond to a remission?
Dr. Cadavid
Ultimately, it will come from the results from the trials. But if you think about demyelination, it is a core component of MS. All forms of MS – from very early to very late – have a loss of myelin. So as long as there is ongoing or preexisting loss of myelin, we believe there is a potential for a remyelinating therapy like anti-LINGO to help the patients.
MSDF
Now you mentioned not only relapsing-remitting but secondary-progressive, and I'm sure you know there's a long history of things that have not worked well for progressive disease. Do you have a reason to believe that anti-LINGO-1 will be efficacious for progressive disease?
Dr. Cadavid
So, Bob, it is true that there really no effective therapies in SPMS right now. It is an area that we are focusing on anti-LINGO because we know there is extensive demyelination in secondary-progressive MS. Interestingly, there is a lot of cortical demyelination with relative preservation of axons and neurons. So we believe that if this drug is capable of repairing the myelin we could actually be able to help patients with SPMS. The phase 2 program includes patients with SPMS, so we obviously are looking forward to the results from the ongoing phase 2 trials to help us make decisions on next steps.
MSDF
Why not primary progressive?
Dr. Cadavid
Primary progressive MS is also under consideration. Right now we have to focus. Obviously what we learned from secondary-progressive MS will also inform us as to pursue primary progressive MS. We are aware there is a high unmet need, and we keep those patients at heart too.
MSDF
Just in terms of procedurally a technique why are you focusing on secondary-progressive before primary progressive?
Dr. Cadavid
So there are some practical reasons. One of them is that SPMS is viewed as closer to relapsing-remitting MS relative to primary progressive MS. So in the phase 2 trial, we have to try to keep some focus on the population. If we spread too much, it may become more difficult to actually interpret the data. There is a strategic reason as SPMS is closer to RRMS than PPMS is.
MSDF
Well, Dr. Cadavid, I've come to the end of my prepared questions. Is there anything I haven't asked that I should have asked or anything you'd like to add?
Dr. Cadavid
I like to finish by saying that the results of the RENEW trial it's really the first time we have seen evidence from the human brain that it appears possible to repair the myelin. This is a very important step in the field. There is a lot of work to do. But it is encouraging news, and we are happy to share this with the community. And Biogen is very committed to MS and to help patients who are living with this chronic disabling condition. So we welcome the news, and we also are ready to embrace the following stages of drug development, which are obviously very challenging.
MSDF
Well Dr. Cadavid, thank you very much.
Dr. Cadavid
Thank you, Bob, was a pleasure.
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MSDF
Thank you for listening to Episode Forty-One 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 editor@msdiscovery.org.
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