Rituximab as treatment for anti-MuSK myasthenia gravis: Multicenter blinded prospective review.

Published

Journal Article

OBJECTIVE: To evaluate the efficacy of rituximab in treatment of anti-muscle-specific kinase (MuSK) myasthenia gravis (MG). METHODS: This was a multicenter, blinded, prospective review, comparing anti-MuSK-positive patients with MG treated with rituximab to those not treated with rituximab. The primary clinical endpoint was the Myasthenia Gravis Status and Treatment Intensity (MGSTI), a novel outcome that combines the Myasthenia Gravis Foundation of America (MGFA) postintervention status (PIS) and the number and dosages of other immunosuppressant therapies used. A priori, an MGSTI of level ≤2 was used to define a favorable outcome. Secondary outcomes included modified MGFA PIS of minimal manifestations or better, mean/median prednisone dose, and mean/median doses of other immunosuppressant drugs. RESULTS: Seventy-seven of 119 patients with anti-MuSK MG evaluated between January 1, 2005, and January 1, 2015, at 10 neuromuscular centers were selected for analysis after review of limited clinical data by a blinded expert panel. An additional 22 patients were excluded due to insufficient follow-up. Baseline characteristics were similar between the rituximab-treated patients (n = 24) and the controls (n = 31). Median follow-up duration was >3.5 years. At last visit, 58% (14/24) of rituximab-treated patients reached the primary outcome compared to 16% (5/31) of controls (p = 0.002). Number needed to treat for the primary outcome is 2.4. At last visit, 29% of rituximab-treated patients were taking prednisone (mean dose 4.5 mg/day) compared to 74% of controls (mean dose 13 mg/day) (p = 0.001 and p = 0.005). CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that for patients with anti-MuSK MG, rituximab increased the probability of a favorable outcome.

Full Text

Duke Authors

Cited Authors

  • Hehir, MK; Hobson-Webb, LD; Benatar, M; Barnett, C; Silvestri, NJ; Howard, JF; Howard, D; Visser, A; Crum, BA; Nowak, R; Beekman, R; Kumar, A; Ruzhansky, K; Chen, I-HA; Pulley, MT; LaBoy, SM; Fellman, MA; Greene, SM; Pasnoor, M; Burns, TM

Published Date

  • September 5, 2017

Published In

Volume / Issue

  • 89 / 10

Start / End Page

  • 1069 - 1077

PubMed ID

  • 28801338

Pubmed Central ID

  • 28801338

Electronic International Standard Serial Number (EISSN)

  • 1526-632X

Digital Object Identifier (DOI)

  • 10.1212/WNL.0000000000004341

Language

  • eng

Conference Location

  • United States