How to recruit multiple sclerosis patients for clinical trials

How many Americans have multiple sclerosis?

A study led by Mitchell Wallin and published in Neurology in 2019 found a steady rise in MS prevalence in the United States to nearly 1 million people (Wallin et al. via HCPLive).

A simple ratio puts the competition in perspective. Nearly 1 million people divided across 157 recruiting studies is roughly 6,369 people per study nationally, before eligibility criteria, geography, and patient willingness cut the pool down. Most of those patients will never hear about a trial unless a neurologist brings it up.

MS has fewer recruiting studies than the cancers on this list, and only 30 of its 111 recruiting interventional trials are industry funded. Academic and government sponsors run most MS research right now. For an independent site, each industry MS trial is a valuable and competitive opportunity.

How many multiple sclerosis trials are recruiting in the United States right now?

As of October 6, 2026, ClinicalTrials.gov lists 157 multiple sclerosis studies with a status of recruiting and at least one location in the United States (ClinicalTrials.gov). Of those, 111 are interventional trials and 46 are observational studies. Industry is the lead sponsor on 40 of them, about 25%. Academic centers, cooperative groups, and government sponsors run the rest.

Interventional multiple sclerosis trials by phase:

The median interventional trial targets 60 participants in total across all of its sites. The typical industry funded trial lists 8 recruiting locations in the United States, so each site is usually expected to deliver a small slice of that total, and sponsors notice quickly which sites deliver none.

Where are multiple sclerosis trials concentrated?

Every location on every recruiting study counts here. Together the 157 studies list 738 recruiting US locations. These states host the most recruiting studies:

The most frequently listed institutions include National Institutes of Health Clinical Center, Massachusetts General Hospital, Medical College of Wisconsin, and University of Alabama at Birmingham. The industry sponsors with the most recruiting multiple sclerosis trials right now include Novartis Pharmaceuticals, TG Therapeutics, Bristol Myers Squibb, AstraZeneca, and Zenas BioPharma (USA),. If your site sits in one of the top states, you are recruiting from the same patient population as several large academic programs at once, and the patients who reach you will mostly come through the physicians who already treat them.

Which physicians manage MS patients?

• General neurologists, who manage a large share of MS patients in community practice. The AAMC counts 14,949 active neurologists (AAMC 2024 via Becker's).
• MS specialists at comprehensive MS centers, who see complex and progressive cases.
• Neuro ophthalmologists, who often see optic neuritis before the MS diagnosis.

What decides eligibility in MS trials?

MS protocols typically specify the disease course (relapsing or progressive), a disability score range, recent relapse or MRI activity, and which disease modifying therapies the patient has used. Tufts CSDD reports a 57% screen failure rate for CNS and neuroscience trials, compared with 36.3% across all therapeutic areas (Tufts CSDD). That gap is why MS referrals need to come with the most recent MRI report and treatment history, so the site can prescreen before a costly visit.

Why physician referral matters more than volume

A large patient population does not fill trials on its own. Physicians refer a median of about five patients into clinical trials per year, which is less than 0.2% of their annual patient volume (Getz, Applied Clinical Trials). In Tufts CSDD research, physicians and nurses named lack of access to study information and lack of time as the main reasons they do not refer, and physicians in clinical practice were 2.7 times more likely to refer than physicians in hospital settings (Tufts CSDD via Applied Clinical Trials).

That is the gap a site can close. The physicians who diagnose and manage your study population already know which patients are likely to qualify. They need a short, specific summary of your open study, a named coordinator, and a reason to believe the patient will come back to them.

A practical multiple sclerosis referral plan for your site

1. Pull the live ClinicalTrials.gov list for your state and note which competing studies are enrolling the same population within driving distance of your site.
2. List the neurologists and MS centers within a realistic drive of your site. Community practices come first.
3. Send each physician a one page study summary: the diagnosis, the two or three criteria that decide most eligibility, what the patient will experience, and the coordinator's direct line.
4. Follow up by email and LinkedIn, and call the practices that engage.
5. Report back to the referring physician on every patient, whether or not the patient enrolls.

See how to get physicians to refer patients and the referral letter guide for templates.