Design: Prespecified analysis of a phase 3, randomised, placebo-controlled trial (MINT)
Population: 238 adults with AChR+ or MuSK+ generalised myasthenia gravis, MG-ADL 6–10
Primary outcome: Exacerbations including crisis, MG-ADL worsening or rescue therapy
Effect: HR 0.41 (95% CI 0.24–0.70) at week 26 overall; AChR+ HR 0.39 at week 52

MINT was a phase 3 placebo-controlled trial of inebilizumab, a CD19 B-cell-depleting antibody, in 238 adults with generalised myasthenia gravis, either AChR- or MuSK-antibody positive, across 18 countries. Everyone underwent a protocol-driven corticosteroid taper to 5 mg a day or less.

This prespecified analysis counted exacerbations, defined as myasthenic crisis, worsening of individual daily-living scores, or rescue with intravenous immunoglobulin or plasma exchange. Inebilizumab reduced their risk in the combined population by week 26 (HR 0.41, 95% CI 0.24 to 0.70), in AChR-positive patients by week 52 (HR 0.39) and in MuSK-positive patients by week 26 (HR 0.21, 0.06 to 0.79).

The steroid taper matters: it tested whether the drug could hold disease while the main existing control was withdrawn. Inebilizumab is approved for neuromyelitis optica spectrum disorder in several countries; its status for myasthenia gravis in India should be checked.

Inebilizumab lowered exacerbations and rescue therapy while steroids were tapered.
Benefit was seen in both AChR- and MuSK-positive generalised myasthenia gravis.
The MuSK estimate rests on a small subgroup with a wide interval.
Check local regulatory status before considering it for myasthenia gravis.

Why it matters

Steroid dependence is a central burden of myasthenia, and this tested a drug under taper.

The statistics, in plain English

A hazard ratio of 0.41 means about 60% lower risk of exacerbation over the period. The MuSK interval (0.06 to 0.79) is wide because the subgroup was small, so its size is uncertain even though it excludes 1.