Abstract：
BACKGROUND: Several studies reported lower drug concentrations with subcutaneous natalizumab compared to intravenous natalizumab. With the emergence of extended interval dosing, gaining more insight into lower concentrations after subcutaneous administration is essential.
METHODS: We compared serum trough concentrations between subcutaneous and intravenous administration within a matched cohort (n = 50).
RESULTS: Subcutaneous administration (n = 25) was associated with lower concentrations compared to intravenous administration (n = 25) (log-B=-0.28, p = 0.01). In an exploratory group of 11 patients receiving extended interval dosing of subcutaneous natalizumab, the median trough concentration was even lower.
CONCLUSIONS: Subcutaneous natalizumab can lead to lower drug concentrations, potentially limiting extended interval dosing.
METHODS: We compared serum trough concentrations between subcutaneous and intravenous administration within a matched cohort (n = 50).
RESULTS: Subcutaneous administration (n = 25) was associated with lower concentrations compared to intravenous administration (n = 25) (log-B=-0.28, p = 0.01). In an exploratory group of 11 patients receiving extended interval dosing of subcutaneous natalizumab, the median trough concentration was even lower.
CONCLUSIONS: Subcutaneous natalizumab can lead to lower drug concentrations, potentially limiting extended interval dosing.
摘要：
背景：一些研究报道，与静脉注射那他珠单抗相比，皮下那他珠单抗的药物浓度更低。随着间隔时间延长给药的出现，在皮下给药后,更深入地了解低浓度是至关重要的.
方法：我们比较了匹配队列中皮下和静脉给药之间的血清谷浓度（n=50）。
结果：与静脉给药（n=25）相比，皮下给药（n=25）与较低的浓度相关（log-B=-0.28，p=0.01）。在一组11名接受延长间隔皮下那他珠单抗给药的患者中，中位谷浓度甚至更低。
结论：皮下那他珠单抗可导致药物浓度降低，可能限制延长间隔给药。
方法：我们比较了匹配队列中皮下和静脉给药之间的血清谷浓度（n=50）。
结果：与静脉给药（n=25）相比，皮下给药（n=25）与较低的浓度相关（log-B=-0.28，p=0.01）。在一组11名接受延长间隔皮下那他珠单抗给药的患者中，中位谷浓度甚至更低。
结论：皮下那他珠单抗可导致药物浓度降低，可能限制延长间隔给药。
