Treatment Goals With MG

Welcome, everyone. I'm Dr. John Whyte, the Chief Medical Officer of WebMD. Today, I want to talk about a serious autoimmune condition called myasthenia gravis. It comes from the Latin and Greek which means grave muscle weakness.

Almost 60,000 people in the United States are living with this condition. Basically, it's a breakdown in communication between your nerves and your muscles. And it's usually those voluntary skeletal muscles around the eyes, the throat, our limbs, our arms and legs. There's no cure but we do have effective treatments.

Joining me to discuss your options are two experts-- Dr. Pushpa Narayanaswami, who's an Associate Professor of Neurology at Harvard Medical School in Beth Israel Deaconess Medical Center, and Dr. Donald Sanders. He is Professor of Neurology at Duke University School of Medicine. Doctors, thanks for joining me. Dr. Pushpa, I want to start with you. What are the current treatment options when someone is newly diagnosed with myasthenia gravis?

These are really exciting times, I think, for patients with myasthenia gravis. In 2017, a drug was approved and that was the first FDA drug approved in over 40 years in the treatment of myasthenia gravis.

40 years?

Yeah.

Wow.

PUSHPA NARAYANASWAMI: And since then, there's one-- there have been another approved. So very exciting times. But that doesn't mean that patients did not get treated before these drugs were available.

There are treatments that we sort of classified into two big groups. The first group is treatments that just help with the symptoms of the disease, so symptomatic treatments. And the second group is treatments that actually are disease modifying.

And what does disease modifying mean? We do know that myasthenia gravis is an autoimmune condition. So there's an autoimmune response that's directed at the postsynaptic membrane of the neuromuscular junction. And therefore, we use medications in order to modulate that autoimmune response.

And those medications may be oral. They may be intravenous. And we also have something called plasma exchange, which literally physically removes the antibodies from the blood. It's a temporary but excellent and very effective treatment.

We have some surgeries. The surgery that is used in the treatment of myasthenia gravis is a thymectomy or removal of the thymus gland. The thymus gland is a gland that's involved in our autoimmune responses. And it sort of sits in the upper chest between the two lungs, just over the heart. So removing the thymus is one treatment option.

Dr. Sanders, patient comes in, newly diagnosed myasthenia gravis. How do you work through the various treatment options with the patient?

DONALD SANDERS: The first treatment that we use in practically all patients is the symptomatic treatment, cholinesterase inhibitors that produce a temporary improvement of the weakness by enhancing the effect of the neurotransmitter from the nerve to the muscle. These have been used for decades, over 50 years. And there are several major benefits to them.

First they work very quickly, within a matter of minutes, which obviously is very important in the treatment. So cholinesterase inhibitors are our first line treatment in practically all patients. However, they don't produce what we consider to be adequate response and long-term response in most patients. Very few patients are adequately improved with cholinesterase inhibitors alone.

So we typically then move on to immunomodulatory therapies that are designed to suppress the underlying autoimmune process that produces the condition. And the most long lasting or term of these is corticosteroids. And they work extremely well in most patients with myasthenia but unfortunately carry with them some significant long-term side effects. And then we move on, typically with another form of immunosuppression such as azathioprine or mycophenolate mofetil, which have a more long lasting effect.

So you've both mentioned a lot of options. Do patients ever go into remission, Dr. Pushpa? Is this something that they're going to need to be on for the rest of their lives?

Very good question. And something that patients ask, right? I mean, many patients will say, they're on a huge bunch of medications, especially, sometimes initially you really hit the disease hard. So when we see these patients, we use some criteria or we use some classifications of how severe the disease is and where they're at with their disease, what muscle it affects. We want to get them to another place from there.

And so, how do we measure that? We use a scale called the Myasthenia Gravis Post-Intervention Status Scale. And so, there are several classifications there. A patient can be worse, of course. A patient can be improved. And then, a patient can have something that we call minimal manifestations. So what does that mean? It means that the patient comes into your office and when you talk to them, they tell you that they really don't have any disability or any functional limitation from the disease. But when you examine them, you may find a little bit of muscle weakness, of eye closure, or maybe a little deltoid weakness, or shoulder weakness. A little bit of weakness that's really not impacting them. And we term that minimal manifestations.

And then, we have the group remission-- P-I-S remission, Post-Intervention Standard Remission. It could be pharmacological remission, which is they're on drugs and they're in remission, which means there's nothing-- no symptoms, no signs of the disease. Or complete stable remission, which means they're off drugs.

Now, there's a very small percentage of patients who go into complete stable remission. So then what am I going to tell my patient? I'm going to say, this is my goal for treatment. And that is I want to get you to minimal manifestations or better. And I want to make sure that the side effects of your treatment are tolerable and they are mild and they really don't require any intervention.

Dr. Sanders, what's your message for patients that are watching that have myasthenia gravis or know someone who has it?

Well, as Pushpa mentioned, I tell them that our goal is to get you to a point where you have no disability from your disease, what we call minimal manifestations or better. And in our experience, 75% of patients reach that goal with the current therapies that we have available. And the majority of patients reach that goal within a year after we begin therapy.

So that's what I tell them they have to look forward to, that that's the optimal therapy, and that's what we're going to be working towards. And I emphasize to them that there are various ways to treat them to reach that goal and the choice amongst these therapies varies depending upon the characteristics of the specific patient.

Absolutely. As you point out, there are a lot of options that patients now have available to them. And hopefully, they'll have learned more about the different types of drugs that are available and options, and then talk about it to their doctor. I want to thank you both for taking the time today to talk about what are the treatment options available for myasthenia gravis.

Thanks, John. Pleasure to be here.

Yeah. Pleasure, John. Thank you.