FDA Approves Weekly Klygefa Injection for Generalized Myasthenia Gravis: 260-Person Trial Shows 1.6-Point Advantage on Daily-Living Scores at Week 26, With Boxed Warning for Meningococcal Infection
The U.S. Food and Drug Administration approved Alexion Pharmaceuticals' Klygefa (gefurulimab-gaks) on November 13 for adults with generalized myasthenia gravis who test positive for anti-acetylcholine receptor antibodies. The medicine is a once-weekly injection under the skin that patients can give themselves, or a caregiver can give, after training, following an initial loading dose, with the weekly amount based on body weight.
The FDA prescribing information describes a 26-week trial of 260 adults, with 131 people assigned to Klygefa and 129 to placebo, while patients could continue their existing myasthenia gravis medicines at stable doses. The main measure was a score of how much the disease interfered with daily activities, running from zero to 24, with higher numbers meaning greater difficulty. At 26 weeks, scores had improved by an adjusted average of 4.2 points with Klygefa and 2.6 points with placebo, a statistically significant difference of 1.6 points. A separate measure of muscle weakness also improved more with Klygefa than with placebo.
Klygefa blocks complement C5, part of the immune system. Its label carries a boxed warning for serious and life-threatening meningococcal infections, and patients remain at increased risk even after vaccination. The label calls for meningococcal vaccination before treatment, generally at least two weeks before the first dose, and sets out precautions when treatment must begin urgently. The drug is available only through a restricted safety program, and prescribers must enroll. Injection-site reactions were the most common adverse reactions in the placebo-controlled study, occurring in 12 percent of Klygefa patients compared with 3 percent on placebo. The label says safety and effectiveness in children have not been established.
Source: U.S. Food and Drug Administration
Published by GSM · USA (original Chinese edition)
Photo: 图：Alexion Pharmaceuticals 总部大楼，Klygefa 由该公司研发。来源：ajay_suresh，Wikimedia Commons，CC BY 2.0。 / Photo: The Alexion Pharmaceuticals headquarters building; Klygefa was developed by the company. Source: ajay_suresh, Wikimedia Commons, CC BY 2.0.
