Promising Experimental Treatments for Multiple Sclerosis

Medically Reviewed by Christopher Melinosky, MD on April 15, 2022
5 min read

What’s on the horizon for people with multiple sclerosis? Dedicated doctors, scientists, and volunteers are working today to answer that question and find tomorrow’s breakthroughs.

Several experimental treatments are being studied to figure out whether they’re safe and effective for people with different kinds of multiple sclerosis (MS) and at different points in their journey.

The main research goals are to find new ways to stop MS from getting worse or even to reverse nerve damage and the disability that can come with it. Eventually, the hope is to end MS forever.

That’s a tall order for sure, but progress is being made in laboratories and medical centers all around the world.

One of the most exciting new drug groups being studied is called BTK (Bruton’s tyrosine kinase) inhibitors for relapsing-remitting MS, says Ben Thrower, MD, a neurologist and medical director of the Andrew C. Carlos MS Institute at Shepherd Center in Atlanta and senior medical advisor for the Multiple Sclerosis Foundation.

BTK inhibitors are what’s called disease-modifying therapy. The goal of disease-modifying therapy is to stop progression of disability, no new lesions (sclerosis or scarring) on MRI scans, and no relapses.

MS drugs that have evolved over the last 5 years are what Thrower would call “me too” drugs. They’re new, but they work the same way as existing drugs. Each new medication might be a bit safer or more convenient to take.

But BTK inhibitors (also called BTK blockers) are a totally new class of drugs that work in a new way. They tamp down immune system B cells and macrophages. Macrophage is Latin for “big eaters,” Thrower says. These are cells that chew up things. Ideally, that involves things like bacteria and precancerous cells. But MS is an autoimmune disease, and the immune system targets healthy cells it shouldn’t. Macrophages in a person with MS may nibble on the myelin, the protective coating on nerve cells, causing damage.

B cells have a few roles in the immune system. “They create antibodies when they grow up to be (blood) plasma cells and coordinate T-cell activity,” Thrower says. The hope is that BTK inhibitors will reduce inflammation and damage by working through both pathways.

But are these drugs ready for use? Three are in the last phase of MS clinical trials and could be ready in 2023, Thrower says. Another plus for BTK inhibitors: They’re pills and can be taken at home. Many other MS disease-modifying drugs are shots or infusions.

When you have multiple sclerosis, your immune system attacks your central nervous system. So what if doctors could flush out your “bad” immune system and give you a new one? That’s the basic idea behind a type of bone marrow transplant called autologous hematopoietic stem cell transplant (AHSCT).

How does this work? Thrower explains it this way:

  • Immature stem cells made in your bone marrow are removed from your blood.
  • These cells are sort of cloned and many copies are made.
  • The bad immune system’s “hard drive” is wiped clean with high-dose chemotherapy.
  • The immune system is rebooted with the fresh stem cells that don’t attack your nervous system.

Since they’re your cells, they can’t be rejected. But it will take your body about a month to replace your immune system. That puts you at risk of potentially life-threatening infections, including COVID-19 and others.

The procedure is not new but not approved by the Food and Drug Administration. It could be soon, Thrower says.

In fact, the National Institutes of Health is sponsoring a clinical trial comparing AHSCT against the most widely used and effective treatments for relapsing-remitting MS.

Even though AHSCT isn’t approved, experts know a lot about the best candidates for this ambitious therapy. It’s most successful in people with aggressive relapsing-remitting MS who are under age 50, according to Thrower.

This is the same procedure actress Selma Blair had in 2019, he adds. Her journey is the subject of a 2021 documentary called Introducing, Selma Blair.

Talk to your neurologist about whether you should try AHSCT. Many Americans go to other countries for this treatment.

Another stem cell transplant therapy being tried at Atlanta’s Shepherd Center is intended to treat all types of MS: relapsing-remitting, primary progressive, and secondary progressive. The procedure uses what’s called mesenchymal stem cells. It may be able to repair damage and reverse disability.

Mesenchymal cells are more mature than embryonic stem cells, which have a better ability to repair but are risky. “Once you put embryonic cells into the body, you lose control and you can’t take them out once they’re in. They can turn into cancerous cells or tissue you don’t want them to develop into,” Thrower says.

“Embryonic stem cells are like a genie in a bottle, you don’t know whether you’ll get a good genie or a bad genie,” he says.

Mesenchymal cells offer more control and are safer to use. The trial in Atlanta infuses these cells into volunteers through a vein. Unlike AHSCT, it doesn’t destroy the immune system.

But the jury is still out on this approach. It’s only in the first phase of research, so it’s years away from becoming an approved treatment.

Researchers are looking at existing drugs that show promise in treating MS:

Ibudilast. This is a drug used for asthma, primarily in Asia. Researchers hope it can stop progression in primary and secondary progressive MS. It blocks an enzyme called phosphodiesterase and may reduce inflammation and protect nerves. Ibudilast is a pill in the second phase of research.

Clemastine. Researchers at the University of California at San Francisco tested many different drugs in a test tube to see if any of them might repair myelin. They “got a hit” on the allergy medication clemastine, Thrower says.

“The interesting thing with these studies is you’re looking for neural repair in a test tube with molecules that by all rights shouldn’t have the ability to repair in the central nervous system. So you’re showing they repair, but you don’t know why. It’s sort of a backwards way of doing research, but it’s very fast because these are already FDA-approved medications so you know they’re safe,” Thrower says.

Clemastine is now in phase II trial in hopes of reversing MS disability.

Cure means different things to different people, Thrower says. If you’re newly diagnosed with no disability and take a highly effective disease-modifying therapy that stops MS in its tracks, that effectively would be a cure. The BTK drugs or AHSCT might fall into that camp, Thrower says.

The bar is higher if you’re disabled and in a power wheelchair, Thrower says. A cure to you would mean stopping progression and reversing disability. That’s where therapies like mesenchymal stem cell treatment might come into play.