Ravulizumab reduces clinical deterioration in patients with generalized myasthenia gravis

Key takeaways:

• Fewer clinical deterioration events were reported in patients receiving ravulizumab (9.3%) vs. placebo (16.9%).
• Patients who switched from placebo to ravulizumab had a reduction in clinical deterioration events.

Ravulizumab was associated with fewer clinical deterioration events in adults with anti-acetylcholine receptor antibody-positive generalized myasthenia gravis, according to a poster at the 2023 MDA Clinical & Scientific Conference.

Seeking “to assess ravulizumab’s efficacy in reducing acute clinical-deterioration events,” Renato Mantegazza, MD, research director at the IRCCS Carlo Besta Neurological Institute Foundation, and colleagues conducted the CHAMPION MG study.

They enrolled 175 adults with anti-acetylcholine receptor antibody-positive generalized myasthenia gravis (AChR Ab+ gMG), who were randomized to receive ravulizumab (n = 86) or placebo (n = 89) for 26 weeks. Patients completing the randomized controlled period could enter an open-label extension phase and receive ravulizumab for up to 4 years.

The primary outcome was change from baseline in Myasthenia Gravis-Activities of Daily Living (MG-ADL) total score at 26 weeks, while secondary outcomes included change from baseline to 26 weeks in the Quantitative Myasthenia Gravis (QMG) total score, percentage of participants with a QMG score reduction of at least five points at week 26 and percentage of participant with an MG-ADL score reduction of at least three points at week 26.

Clinical deterioration, defined as a myasthenic crisis, included severe weakness requiring intubation or delaying extubation after surgery, significant worsening of symptoms or administration of rescue therapy. Researchers assessed these events in an interim analysis of data up to week 60.

In the randomized controlled period, fewer clinical deterioration events were reported in the ravulizumab group (9.3%) compared with the placebo group (16.9%).

During the open-label extension phase, in which 83 patients continued ravulizumab and 78 were switched from placebo to ravulizumab, researchers reported a substantial reduction in clinical deterioration events in those who switched from placebo to ravulizumab (4.8%).

“Ravulizumab treatment was associated with numerically fewer clinical deterioration events vs. placebo in patients with AChR Ab+ gMG,” Mantegazza and colleagues wrote. “When patients were switched from placebo to ravulizumab, there was a statistically significant reduction in the exposure-adjusted clinical deterioration event rate.”