Advances in the Treatment of Spinal Muscular Atrophy - Episode 18
Crystal Proud, MD: We've reviewed the diagnosis of SMA [spinal muscular atrophy] and its phenotypes. We have talked about the interdisciplinary management that it requires. We've talked about the treatments available as well as 1 that is up for FDA approval.
Julie, I'd like to start with you and ask what you think would be a take-home message for the community neurologists who may see a patient either with a diagnosis of SMA already or who may be manifesting symptoms that can be attributed to SMA.
Julie Parsons, MD: There are a lot of messages that we can talk about. The first that we have hope and that we have treatments available that we haven't had in the past, so making a diagnosis is absolutely critical in this day and age because it leads to the ability to treat. Genetic testing is easily, readily available. The turnaround time is quick. There is free genetic testing for SMA, so that we are able and should be able to test any patient to confirm this diagnosis and then move forward with treatment.
We’re all extremely enthusiastic about the opportunities for treatment that we have available now for all age populations. We may have touched on this, but onasemnogene abeparvovec-xioi is indicated for children under the age of 2. Nusinersen is indicated for any patient with any type of SMA, with 5q SMA, any age. And hopefully, risdiplam, for which the trials have gone up from infancy to age 60 will, if it's approved, have indication for the general population as well.
There are those treatments that will be available, which is very exciting. The other message is that we're not done. We didn't talk about some of the ancillary trials that are ongoing, such as Scholar Rock [Inc], which is looking at the anti-myostatin inhibitors. There are add-on therapies that we will have available as well, so my message would be that we need to diagnose and treat patients.
We need to treat them early, and the future is extremely bright for providing care for these patients. Neurologists and pediatric neurologists are vital in the expert management of these patients, but the key to taking care of these patients is the primary care providers who will interface with the multidisciplinary clinics to make certain that no matter where a patient is in the United States, they have access to excellent care.
Crystal Proud, MD: Absolutely. I think those are great take-home messages. John, are there things that you would add to that?
John Brandsema, MD: As much as we’re all very excited about these new treatment opportunities, sometimes the messaging tends to flip a little bit, especially with gene therapy where people say, “OK, I got my gene therapy. It was early on. Now I'm done. I can go live my normal life,” which is what we hope may happen if we intervene early enough. But there are still symptomatic aspects of living with SMA in most of the people who are being treated. We know that now following the cohort.
There's also a huge unknown to all of this; these are all very new, and we don't know the long-term durability or the long-term safety of any of these approaches in great detail. It's very important to maintain that relationship with the specialized care center and with people who have expertise in SMA. Sometimes, the primary care provider can help encourage this because, if somebody is generally doing well, they tend to see less motivation for going back to clinic, and encouraging that care relationship is so important to ensure that we're vigilant.
In the case of these treatments that require ongoing therapy, sometimes that's also necessitated by the insurance authorization process and other things, that you continue to collect data to ensure that the authorization continues. There are unique aspects if risdiplam also comes into our armamentarium in that this is a daily medication that you have to remember to take. This is something that's going to lead to all sorts of questions if there are life factors that come up that make that access more challenging. Overall, I would say that there needs to be an SMA interdisciplinary care team in someone's life if they are living with SMA.
Crystal Proud, MD: Nancy, any thoughts that you would add to those?
Nancy L. Kuntz, MD: No, I would just emphasize the pivotal role that primary care providers have in this because we have a long way forward to make sure that we're getting prompt diagnoses. If everyone recalls that there is sponsored, free testing, that this is a treatable disorder, and that we should get the testing, particularly in areas where there is not newborn screening, as quickly as people think of the possibility of a diagnosis of spinal muscular atrophy, so it can be either ruled in or ruled out, and then proceed from there.
Even in areas where there is newborn screening, we have problems of people living near the edge of a state, and the newborn screening is done by the state, so it depends on where the child was born. So there may be, in some communities, a little bit of uncertainty about whether the child has been screened. Then, as we already mentioned, there is a very small incidence of false negatives in newborn screening for spinal muscular atrophy, so if people continue to have clinical concerns, it's important very early to have a plan: a go-to person to ask some advice and get some evaluation and testing on a child. We know all of the studies that we've mentioned and that you highlighted emphasize that the earlier the treatment is started, the better the child does.
Julie Parsons, MD: We were very good about trying to address a lot of broad issues during this discussion, but an underpinning of all of this is that there are published consensus care guidelines. For primary care providers or neurologists who are not accustomed to taking care of patients who have spinal muscular atrophy, the consensus care guidelines are an invaluable tool for caring for patients with SMA and being able to go forward in a more granular level than we did in this in this discussion in terms of some of the specifics of providing excellent care as well. That's a wonderful resource that is available to providers.
Crystal Proud, MD: Thank you for reminding us of that. This has really been a great discussion. Thank you. On behalf of the panel, we hope you have found this NeurologyLive® Peer Exchange to be useful and informative.