New Multiple Sclerosis Medications Being Developed

Before 1993, there were no medications approved specifically to treat multiple sclerosis (MS). But then, researchers developed interferon beta 1B (brand name: Betaseron). Soon after, two more drugs were approved by the U.S. Food and Drug Administration (FDA), and the three medications were soon dubbed the ABC drugs: Avonex, Betaseron and Copaxone.

Today, there are more than 20 drugs approved by the FDA to treat MS—and many more promising ones are being developed or are already in clinical trials.

“We have come a long, long way,” said Jacquelyn “Jacci” Bainbridge, PharmD, a professor and vice chair of research in the Department of Clinical Pharmacy at the Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus. Dr. Bainbridge is a clinical pharmacy specialist who works with MS patients.

In MS, a person’s immune system mistakenly attacks, damages and destroys the protective sheath around nerves—called myelin. Without the protective coating, nerves can be damaged. This damage to the central nervous system can cause numbness, weakness, tingling, trouble walking, fatigue, vision problems, cognitive problems and more.

Currently, that damage is permanent. There is no medication that can reverse the damage or cure MS. Instead, today’s medications focus on stopping the damage in its tracks and preventing MS relapses.

There are three main clinical subtypes of MS: relapsing-remitting, secondary-progressive and primary progressive. What medications a person takes depends on several factors, including their type of MS, severity of the disease, potential side effects, and a patient’s preference and lifestyle, according to Krupa Shah Pandey, MD, director of the Comprehensive Care Center for Multiple Sclerosis and Related Disorders at Hackensack Meridian Neuroscience Institute at Hackensack University Medical Center in New Jersey. Dr. Pandey is also an associate professor of neurology at Hackensack Meridian School of Medicine. 

Medications fall into three primary areas: oral (a pill taken by mouth), subcutaneous injections (shots given just under the skin) or infusions (given through an IV). While the medications may work through different pathways in the body, they are all aimed at reprogramming the immune system.

Promising New MS Drugs

Clinicians who treat MS patients are excited about several new drugs coming out soon or still being studied. These include drugs that act in different ways than the currently available medications.

One is the BTK inhibitors, which block a protein called bruton tyrosine kinase (BTK). The protein plays an important role in the development of B cells. B cells are a part of the immune system, so by blocking the protein in MS patients, this type of drug can prevent the immune system from attacking the myelin.

“It’s always good to have different medications that work different ways,” Dr. Bainbridge said. “Some patients may respond better to one mechanism of action versus another. Having different mechanisms of action really widens the playing field and obviously gives patients more choices.”

The first BTK inhibitor likely to be approved by the FDA is tolebrutinib, which is a daily pill, developed by the company Sanofi. In December 2024, the FDA granted a “breakthrough therapy” designation to tolebrutinib for the treatment of adults with non-relapsing secondary-progressive MS. There are currently fewer drugs available to treat this form of MS.

FDA breakthrough therapy designation is designed to fast-track the development and review of medicines that target serious or life-threatening conditions. It is given only to medications that have shown substantial improvement to patients in a clinical trial.

“BTK inhibitors may end up giving us a new type of very effective therapy,” Dr. Bainbridge said.

BTK inhibitors are also being tested for relapsing-remitting MS. The new drug fenebrutinib is being tested for both forms of the disease by the biotech company Roche. It is in Phase 3 clinical trials, and research results are expected to be announced by the end of 2025. So far, it has shown success. In the Phase II results announced in September 2024, 96% of patients treated with fenebrutinib were free of MS relapses after taking the drug for one year. There was no change in their disability, and disease activity in the brain was suppressed, as shown in MRI scans. Furthermore, 99% of patients were free of T1 gadolinium-enhancing lesions, which are markers of active inflammation, and there was three times more reduction in the volume of T2 lesions.

Another type of drug that is still in the early stages of clinical trials is chimeric antigen receptor T-cell therapy, or CAR T-cell. This is a type of immunotherapy already being used as a cancer treatment. In MS, CAR T-cell therapy would modify a patient’s own immune cells to remove the B cells that attack the body. The patient would have their blood drawn first to collect the T cells. Then the cells would be modified in a lab, removing the B cells, before being infused back into the same patient through an IV.

“If CAR T therapy works, it would essentially cure the patient,” Dr. Pandey said. “It would reverse the patient’s immune system from overreacting, and they may not ever need to be on medication again.”

Repairing the myelin sheath

Researchers are also studying ways to repair the myelin sheath that is damaged in MS. If successful, this would be the first time a medication reverses damage from MS, not just stops it from getting worse.

In January 2025, Contineum Therapeutics enrolled 168 patients in a Phase 2 trial for a drug called PIPE-307 for people with relapsing-remitting MS. PIPE-307 has been successful in treating mice, and a Phase 1 trial with humans showed it was safe. Now, Phase 2 will test how effective it is in MS patients.

PIPE-307 is an antagonist drug, meaning it binds and blocks a receptor. In this case, PIPE-307 targets a receptor known as M1R on cells in the brain. Researchers used a component of green mamba snake venom to help find the elusive M1R cells.

PIPE-307 encourages the cells to develop stem cells called oligodendrocytes, which are the cells that produce myelin. The new oligodendrocytes then wrap new myelin around the nerves with damaged or missing myelin. The drug would be taken with other MS medications that work to prevent relapses and further damage.

A team of researchers at Cincinnati Children’s Hospital is also studying how to repair myelin. They identified a molecule called ESI1 (epigenetic-silencing-inhibitor-1) that reverses histone signals. In mice studies, the researchers showed that histones stop cells from creating myelin. So, by reversing that mechanism, new myelin begins to form. The researchers are continuing to study this new type of therapy.

“It’s a very exciting time for patients who have MS,” Dr. Bainbridge said. “It used to be that we really had no therapies before 1993, so you would just treat symptoms. You really had nothing that was aimed at decreasing the relapse rate that patients can have and prevent them from going into long-term disability. The future is bright.”