New Rx Option for Neuromyelitis Optica Spectrum Disorder?

Phase 3 trial results suggest daratumumab may reduce relapse risk in NMOSD.

Published on Feb. 16, 2026

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A randomized, double-blind, phase 3 trial found that patients with aquaporin-4 immunoglobulin G (AQP4-IgG) antibody-positive neuromyelitis optica spectrum disorder (NMOSD) who received the monoclonal antibody daratumumab were 74% less likely to relapse than those who received placebo, with similar adverse events between groups.

Why it matters

NMOSD is a rare, relapsing autoimmune disorder that can cause severe neurological damage. While there are FDA-approved treatments, researchers say there is a need for additional options, especially for patients who don't respond to or can't tolerate existing therapies. Daratumumab represents a novel approach that targets CD38, a protein expressed on cells that produce the antibodies that damage the nervous system in NMOSD.

The details

The DAWN trial enrolled 135 patients, mostly women, between November 2022 and March 2025. Patients were randomized 2:1 to receive daratumumab or placebo, with all patients also receiving low-dose prednisone. Daratumumab was dosed at 8 mg/kg IV every 2 weeks during induction, then 4 mg/kg IV every 4 weeks during maintenance, for at least 52 weeks. In the per protocol analysis, 69.1% of the daratumumab group were relapse-free at 156 weeks, compared to 14.6% of the placebo group. The overall decrease in relapse risk in the treatment group was 74%. Adverse event rates were similar between the two groups.

  • The DAWN trial enrolled patients between November 2022 and March 2025.
  • The trial results were presented on February 7, 2026 at the ACTRIMS Forum.

The players

Michael Levy

An associate professor at Harvard Medical School and Massachusetts General Hospital, and the lead investigator of the DAWN trial.

Fu-Dong Shi

A neurologist with China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, and a co-author of the DAWN trial.

Benjamin M. Greenberg

A neurologist and vice chair for Clinical and Translational Research at the University of Texas Southwestern, who provided an outside perspective on the trial.

Daratumumab

A monoclonal antibody approved to treat multiple myeloma that was investigated in the DAWN trial for its potential to reduce relapse risk in NMOSD.

Neuromyelitis Optica Spectrum Disorder (NMOSD)

A rare, relapsing autoimmune inflammatory disorder that causes recurrent optic neuritis and myelitis, affecting an estimated 22,000 people in the U.S., mainly women.

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What they’re saying

“This provides definitive evidence that treatment does reduce the risk of relapse. It also improves disability if they don't relapse.”

— Michael Levy, Associate professor at Harvard Medical School and Massachusetts General Hospital (Medscape Medical News)

“This is a totally different mechanism of action, and it offers new therapy for people with NMO, especially in that group of unmet needs — patients who either don't have access or failed or can't tolerate the other therapies.”

— Michael Levy, Associate professor at Harvard Medical School and Massachusetts General Hospital (Medscape Medical News)

“Given the multitude of on-label therapies for NMO, we tend to start with FDA-approved therapies before progressing to any off-label prescribing.”

— Benjamin M. Greenberg, Vice chair for Clinical and Translational Research, University of Texas Southwestern (Medscape Medical News)

What’s next

The researchers don't yet know if daratumumab would provide a shorter-term option, as the ideal treatment duration is still to be determined.

The takeaway

This trial of daratumumab, a novel approach targeting CD38, provides promising evidence for a new treatment option for patients with NMOSD who don't respond to or can't tolerate existing therapies. However, long-term safety data and the optimal treatment duration are still unknown.