NEW YORK – AstraZeneca on Monday announced that the European Medicines Agency's Committee for Medicinal Products for Human Use has recommended approval for its C5 complement inhibitor Soliris (eculizumab) for treating refractory generalized myasthenia gravis (gMG) in patients between 6 and 17 years old who are anti-acetylcholine receptor (AChR) antibody-positive.
CHMP issued the positive opinion based on data from a Phase III trial involving 11 pediatric patients with refractory gMG and a positive serologic test for anti-AChR antibodies. In the study, patients on Soliris had significant improvement in the 39-point Quantitative Myasthenia Gravis severity and function score at 26 weeks compared to baseline.
gMG is a rare, autoimmune neuromuscular disease characterized by loss of muscle function and severe weakness. Around 80 percent of gMG patients have AChR antibodies that bind to signal receptors at the neuromuscular junction between nerve cells and the muscles they control. This binding activates the complement system and causes the immune system to attack the neuromuscular junction. As a result, patients experience inflammation that hinders communication between the brain and the body's muscles.
The initial symptoms of gMG, including slurred speech, double vision, and droopy eyes, typically manifest in women before age 40 and after age 60 in men. In pediatric patients, the onset of gMG is rare and difficult to manage.
"As the disease progresses, [pediatric] patients may become nonresponsive to standard treatments, leaving them at risk for serious complications," John Brandsema, the primary investigator of the Phase III pediatric study of Soliris at the Children’s Hospital of Philadelphia, said in a statement. The data from this trial showing the ability of Soliris to substantially reduce disease severity and symptoms in pediatric gMG patients could potentially transform how this debilitating disease is managed, he added.
Soliris is already approved in the US and EU for adults with gMG who are AChR antibody-positive. According to AstraZeneca, if European regulators approve this expanded indication of the drug in children, it would be the first and only targeted treatment available for this subset of patients.