Department of Pharmacy and Nutrition, Health Economics and Technology Assessment Group; Center for Exact, Natural and Health Sciences, Federal University of Espírito Santo, Alegre, Brazil.
Department of Management and Incorporation of Technologies and Innovation in Health; Secretariat of Science, Technology and Strategic Inputs; Ministry of Health of Brazil, Brazil.
Expert Rev Clin Immunol. 2022 Sep;18(9):879-888. doi: 10.1080/1744666X.2022.2106972. Epub 2022 Aug 5.
Myasthenia gravis is characterized by fluctuating muscle weakness that improves with rest and worsens with effort or throughout the day.
Efgartigimod is a human IgG1-derived Fc fragment modified at five residues to increase its affinity for the neonatal Fc receptor by Abdeg technology. Thus, efgartigimod binds to the neonatal Fc receptor and decreases the levels of IgG, including autoantibodies of this isotype. For acetylcholine receptor (AChR) antibody-positive patients, efgartigimod had a higher proportion of MG-ADL responders than placebo in the first treatment cycle. The mean changes of multiple outcomes from baseline were better for efgartigimod than placebo from weeks 1 to 7 in the first treatment cycle. The decrease of IgG and AChR autoantibodies was 61.3% and 57.6% one week after the first treatment cycle ends, respectively. The most common adverse events were headache, nasopharyngitis, nausea, and diarrhea, which occurred in the same proportion in the efgartigimod and placebo groups. Urinary and upper respiratory tract infections were twice as frequent in efgartigimod-treated patients.
Efgartigimod was efficacious and safe for generalized myasthenia patients with AChR antibody-positive patients. These findings need to be confirmed in AChR antibody-negative patients, and long-term safety studies are currently ongoing.
重症肌无力的特征是波动性肌肉无力，休息时改善，用力或全天恶化。
依库珠单抗是一种人 IgG1 衍生的 Fc 片段，通过 Abdeg 技术修饰了五个残基，以增加其与新生儿 Fc 受体的亲和力。因此，依库珠单抗与新生儿 Fc 受体结合，降低 IgG 水平，包括该同种型的自身抗体。对于乙酰胆碱受体（AChR）抗体阳性患者，依库珠单抗在第一个治疗周期中比安慰剂有更高比例的 MG-ADL 应答者。在第一个治疗周期中，从第 1 周到第 7 周，依库珠单抗的多种结局的平均变化比安慰剂更好。在第一个治疗周期结束后一周，IgG 和 AChR 自身抗体分别下降 61.3%和 57.6%。最常见的不良事件是头痛、鼻咽炎、恶心和腹泻，在依库珠单抗和安慰剂组中发生的比例相同。依库珠单抗治疗的患者尿路感染和上呼吸道感染的频率是安慰剂组的两倍。
依库珠单抗对 AChR 抗体阳性的全身性重症肌无力患者有效且安全。这些发现需要在 AChR 抗体阴性患者中得到证实，目前正在进行长期安全性研究。
