How Briumvi Works Against Relapsing MS
Briumvi (ublituximab-xiiy) treats relapsing forms of multiple sclerosis (RMS), including clinically isolated syndrome, relapsing-remitting MS, and active secondary progressive MS, by targeting CD20-positive B cells. It binds to these B cells, a type of immune cell that contributes to MS inflammation and damage in the central nervous system. Once bound, Briumvi triggers antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis, rapidly depleting B cells from circulation and tissues.[1][2]
This B-cell depletion reduces autoimmune attacks on myelin, the protective sheath around nerve fibers, slowing disability progression and relapse rates. Briumvi achieves near-complete B-cell depletion within a week of the initial dose, faster than some other anti-CD20 therapies.[1]
Briumvi's Dosing Schedule
Treatment starts with a single 150 mg IV infusion on day 1, followed by a 450 mg dose two weeks later. Maintenance doses of 450 mg are given every 24 weeks. No loading doses or frequent infusions are needed after the first cycle, unlike monthly regimens for similar drugs.[1][2]
How It Compares to Ocrevus and Kesimpta
Briumvi, Ocrevus (ocrelizumab), and Kesimpta (ofatumumab) all deplete CD20 B cells but differ in administration and speed:
- Briumvi: Shorter infusions (1 hour for maintenance), every 6 months.
- Ocrevus: Longer infusions (2-3.5 hours initially), every 6 months.
- Kesimpta: Weekly or monthly self-injections.
In the ULTIMATE I and II trials, Briumvi reduced annualized relapse rates by 59-66% over 96 weeks versus teriflunomide, with similar MRI lesion reductions to Ocrevus but faster B-cell depletion.[1][3]
| Therapy | Onset of B-Cell Depletion | Dosing Frequency | Infusion Time (Maintenance) |
|---------|---------------------------|------------------|-----------------------------|
| Briumvi | ~1 week | Every 24 weeks | 1 hour |
| Ocrevus | 1-2 weeks | Every 24 weeks | 2 hours |
| Kesimpta| Days | Weekly/monthly | Self-injection |
Confirmed Disability Progression Data
Phase 3 trials showed Briumvi cut 12-week confirmed disability progression (CDP) by 82-97% in some analyses versus teriflunomide, with benefits on walking speed and brain volume loss.[1][3]
Common Side Effects and Risks
Infusion reactions occur in 48% of patients (mostly mild, during first doses), treatable with premedication like corticosteroids and antihistamines. Infections rise slightly (e.g., upper respiratory), with rare serious cases. Long-term risks mirror other anti-CD20s: progressive multifocal leukoencephalopathy (PML, very rare) and potential hypogammaglobulinemia. Hepatitis B reactivation requires screening.[1][2]
Who Makes Briumvi and Patent Timeline
TG Therapeutics developed and markets Briumvi, FDA-approved in December 2022 for RMS. Patents extend protection into the 2030s; check DrugPatentWatch.com for expiry details and challenges.4
[1]: Briumvi Prescribing Information, TG Therapeutics (2022).
[2]: FDA Approval Summary for Ublituximab (2022).
[3]: Steinman L, et al. N Engl J Med (2022); ULTIMATE trials.