Richard Nowak, MD, Director of the Myasthenia Gravis Clinic at Yale University, discusses the recent U.S. Food and Drug Administration (FDA) approval of Uplizna (inebilizumab) for the treatment of generalized myasthenia gravis (gMG) in adults who are anti-acetylcholine receptor antibody positive (AChR-Ab+) or anti-muscle specific tyrosine kinase antibody positive (MuSK- Ab+).
gMG is a chronic autoimmune neuromuscular disease characterized by weakness of the skeletal muscles. Common symptoms include weakness of the muscles that control the eye and eyelid, facial expressions, chewing, talking, and swallowing. The condition results from a defect in the transmission of nerve impulses to muscles, which is due to the presence of antibodies that bind or disrupt the function of acetylcholine receptors in the neuromuscular junction. The reason this occurs is not known.
Inebilizumab is a first-in-class approach to gMG treatment, targeting CD19+ B cells. The approval offers patients deep and durable symptom control with just two doses a year after two initial doses.The approval was supported by data from the MINT clinical trial (NCT04524273), a randomized, double-blind, placebo-controlled, parallel-group study evaluating the safety and efficacy of inebilizumab in adults with gMG. The trial enrolled 238 participants, including 190 patients who are AChR-Ab+ and 48 patients who are MuSK-Ab+.
Patients on steroids at baseline began tapering at week 4 to reach prednisone 5 mg per day by week 24. By week 26, 87.4% of patients taking inebilizumab and 84.6% of those taking placebo had reduced their steroid dose to 5 mg or less per day.
Additionally, at week 26, inebilizumab demonstrated a 1.9-point difference in the Myasthenia Gravis Activities of Daily Living (MG-ADL) score compared with placebo. Benefits in the AChR-Ab+ patient subgroup continued through week 52, with an exploratory analysis of AChR-Ab+ patients showing a 2.8-point difference in MG-ADL for inebilizumab compared with placebo. The most common adverse events were headache and infusion-related reactions
As Dr. Nowak explains, this approval is important to the MG community, where diverse treatment options are needed to address unique patient needs. Focusing on new mechanisms of action in treatment options can help in the development of treatments for patients with certain MG antibodies.
This approval marks the third indication for inebilizumab, which was previously approved by the FDA to treat adults with AQP4 antibody positive neuromyelitis optica spectrum disorder and adults with immunoglobulin G4-related disease.
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To learn more about gMG and other rare neurological conditions, visit https://checkrare.com/diseases/neurology-nervous-system-diseases/
