Multiple sclerosis treatment has changed dramatically in the last fifteen years. What was once a disease patients had to manage one relapse at a time can now, for many people, be put into long-term remission with the right disease-modifying therapy. Three of the most effective options are infusion therapies: Ocrevus, Tysabri, and the newer Briumvi. If you’ve been diagnosed with relapsing MS or your neurologist is suggesting moving from an injectable or oral therapy to an infusion, here’s how to think about the differences.
The shared mechanism: B-cell depletion
Two of the three medications discussed here — Ocrevus and Briumvi — work by depleting B cells, a class of immune cell that plays a major role in MS pathology. For decades, MS was thought to be primarily a T-cell driven disease, but research over the past 20 years has revealed that B cells are central to the inflammatory damage that causes relapses and disability progression.
Tysabri works through an entirely different mechanism: it prevents immune cells of any kind from migrating into the brain and spinal cord. Different mechanism, similar goal: stop the inflammatory attack on the central nervous system.
All three are highly effective. The differences lie in convenience, monitoring requirements, and individual safety profiles.
Ocrevus (ocrelizumab) — the first dual-approved MS infusion
How it works: A monoclonal antibody that targets and depletes CD20-positive B cells. By reducing the population of these inflammatory immune cells, Ocrevus has been shown to substantially reduce relapses and slow disability progression.
Schedule: The first dose is split into two infusions of 300 mg given two weeks apart, each lasting about 2.5 hours. After that, maintenance is a single 600 mg infusion every six months — lasting about 3.5 hours, or 2 hours with the newer shorter-infusion protocol. Pre-medications (an antihistamine and a steroid) are given before each session to reduce infusion reactions.
Approved for: Both relapsing forms of MS (RRMS, SPMS with active disease, and CIS) and primary progressive MS (PPMS). Ocrevus was the first MS therapy approved for primary progressive disease — a major milestone, since PPMS had no approved disease-modifying therapy before its approval in 2017.
Watch-outs: Modestly increased infection risk, particularly upper respiratory and herpes infections. Hepatitis B screening is required before starting. There’s a small reported risk of breast cancer that may be slightly elevated in Ocrevus-treated patients — the absolute numbers are small, but you should follow recommended screening. Vaccinations should be brought up to date before starting (live vaccines aren’t recommended during treatment).
Tysabri (natalizumab) — one of the most effective MS therapies
How it works: Blocks alpha-4 integrin, a protein that immune cells need to cross from the bloodstream into the brain and spinal cord. By preventing this migration, Tysabri stops inflammatory cells from reaching the nervous system in the first place.
Schedule: One-hour infusion every 4 weeks, given indefinitely as long as you continue to benefit and tolerate the medication. Some patients eligible for extended-interval dosing receive infusions every 6 weeks instead.
Approved for: Relapsing forms of MS. Tysabri has consistently shown some of the highest efficacy numbers of any MS therapy — relapse rate reductions in clinical trials around 68 percent.
Watch-outs: Tysabri carries a known risk of progressive multifocal leukoencephalopathy (PML), a rare but serious brain infection caused by the JC virus. To manage this risk, all Tysabri patients are enrolled in the TOUCH Prescribing Program, which includes regular JC virus antibody testing and MRI monitoring. The risk is meaningfully higher in patients who are JC-virus antibody positive, particularly those who’ve been on Tysabri for more than two years and have prior immunosuppressant exposure. For JC virus-negative patients, Tysabri is one of the safest highly effective options available.
For patients who are JC-virus positive, the calculus is more complicated. Many neurologists now use shared decision-making to weigh PML risk against the substantial benefit Tysabri provides.
Briumvi (ublituximab) — the newest B-cell therapy
How it works: Like Ocrevus, Briumvi is a monoclonal antibody that depletes CD20-positive B cells. The molecular difference is that Briumvi is “glycoengineered” — modified to be more efficient at killing target cells, which allows for shorter infusion times.
Schedule: The advantage. Initial Briumvi infusion is 4 hours, the second (two weeks later) is just 1 hour, and all subsequent maintenance infusions every six months are 1 hour. Compare that to Ocrevus’ standard 3.5-hour maintenance infusions, and Briumvi can save patients hours of clinic time per year.
Approved for: Relapsing forms of MS (RRMS, SPMS with active disease, and CIS). Not yet approved for primary progressive MS — that remains an Ocrevus distinction.
Watch-outs: Side effect and monitoring profile is similar to Ocrevus, since both deplete B cells. Pre-medications are required. Hepatitis screening before starting. Modestly increased infection risk during treatment. Because it’s newer (FDA approved in late 2022), there’s less long-term safety data than for Ocrevus, but the mechanism is similar enough that most experts expect similar long-term safety.
How neurologists choose
The decision usually comes down to a combination of factors:
- Disease activity. Highly active disease with frequent relapses or rapid MRI progression often points toward Tysabri or one of the B-cell therapies, since both are at the highest tier of efficacy.
- JC virus status. JC-positive patients often steer toward Ocrevus or Briumvi rather than Tysabri because of the PML risk profile.
- Disease type. If you have primary progressive MS, Ocrevus is currently the only infusion therapy approved.
- Lifestyle and time. Briumvi’s 1-hour maintenance infusions every six months are a significant time advantage for patients with demanding work or family schedules.
- Family planning. All three require discussion if you’re planning to become pregnant; B-cell depleting therapies require timing considerations between dosing and conception.
- Insurance and cost. All three are expensive but typically well-covered by insurance for appropriate indications. Manufacturer copay assistance is available.
What about other MS therapies?
This article covers infusion therapies, but MS treatment also includes oral medications (Mavenclad, Tecfidera, Gilenya, Mayzent, etc.), self-injectable medications (interferons, Copaxone), and the newer subcutaneous CD20 therapy Kesimpta. Your neurologist will consider the full menu when recommending a regimen. The reason patients often end up on infusion therapies is efficacy — for moderately to highly active disease, infusions remain among the most effective options available.
Living with MS infusion therapy
One thing that often surprises newly diagnosed patients: being on a highly effective infusion therapy can mean fewer doctor visits, fewer relapses, and a more stable life than the older paradigm of daily injections and frequent flares. For many patients, settling into a once-every-six-months Ocrevus or Briumvi rhythm becomes deeply routine — a half-day appointment twice a year that buys substantial freedom the rest of the time.
At Arbor
We administer all three of these therapies, plus other MS biologics, in a private suite environment with experienced neurology infusion nurses. We coordinate with your neurologist throughout your treatment, handle pre-medications, and monitor closely during and after each infusion.
Read more about each option: Ocrevus, Tysabri, or Briumvi. Or contact us to discuss scheduling.