The FDA (U.S. Food and Drug Administration) has approved the administration of Vyvgart (efgartigimod) for the treatment of generalized Myasthenia Gravis in people that have tested positive for the presence of anti-acetylcholine receptors antibodies in their system.
Myasthenia Gravis is a chronic and neuromuscular condition that causes weakness of the muscles and the weakness exaggerates after periods of activity and improves after rest. The condition is due to the body’s own immunity attacking channels that are necessary for muscle contraction hence primarily affecting voluntary muscles like limbs, face, mouth, etc. In severe forms, muscles used for breathing and swallowing can also be weakened which can become life-threatening.
“There are significant unmet medical needs for people living with myasthenia gravis, as with many other rare diseases,” said Billy Dunn, M.D., director of the Office of Neuroscience in the FDA’s Center for Drug Evaluation and Research. “Today’s approval is an important step in providing a novel therapeutic option for patients and underscores the agency’s commitment to helping make new treatment options available for people living with rare diseases.”
Vyvgart is one of the first new class medications to be approved. It is essentially an antibody fragment that works by binding to the neonatal FC receptor (FcRn), hence preventing the recycling of IgG antibodies back into the blood. The treatment will result in an overall decrease in IgG antibodies that includes the AChR antibodies that are prevalent in myasthenia gravis.
26-week clinical testing was done on 167 patients for the safety and efficacy of Vyvgart. The patients were randomly given either Vyvgart or a placebo. The research showed that 68% responded to treatment during the first cycle of Vyvgart compared to the placebo (30%).
Some of the common, associated side effects with the use of Vyvgart include respiratory tract infections, headaches, and urinary tract infections. Additionally, as the medication causes a reduction in IgG levels, the person can become more susceptible to infections. Hypersensitivity reactions have also occurred like eyelid swelling, shortness of breath. It is advised to stop the infusion in hypersensitivity reactions occurs and then give the patient appropriate therapy. Physicians should give them proper treatment and are also advised to not treat them with Vyvgart if they have an active infection.