Tam Hoi Ki Joshua, Nash Peter, Robinson Philip C
University of Queensland, Brisbane, Queensland, Australia.
Griffith University, Brisbane, Queensland, Australia.
ACR Open Rheumatol. 2021 Oct;3(10):699-706. doi: 10.1002/acr2.11312. Epub 2021 Aug 18.
Biological agents have shown markedly different response rates by baseline C-reactive protein (CRP). Here, we determine the response of patients with nonradiographic axial spondyloarthritis (nr-axSpA) to etanercept stratified by their baseline CRP level.
The EMBARK trial was a phase 3, randomized, double-blind, placebo-controlled study of etanercept in nr-axSpA. The primary endpoint was Assessment of Spondyloarthritis International Society (ASAS) 40 at Week 12, the conclusion of the double-blind phase. It recruited patients who met the ASAS criteria for axial spondyloarthritis, and sacroiliac joint magnetic resonance scans were completed on all patients. In this post hoc analysis, we analyzed outcomes by baseline C-reactive protein (CRP) level of less than 5 mg/L, 5 mg/L to 10 mg/L, and greater than 10 mg/L. The clinical trial outcome data were accessed via the Vivli platform.
In the less than 5 mg/L CRP group treated with etanercept, the ASAS20 response, ASAS40 response, Ankylosing Spondylitis Disease Activity Score-CRP (ASDAS-CRP), and ASDAS-ESR (erythrocyte sedimentation rate) outcomes were 49% (P = 0.84), 26% (P = 0.14), 42% (P = 0.002), and 44% (P = 0.006), respectively. In the 5 to 10 mg/L CRP group treated with etanercept, the ASAS20 response, ASAS40 response, ASDAS-CRP, and ASDAS-ESR outcomes were 56% (P = 0.99), 31% (P = 0.40), 56% (P = 0.16), and 50% (P = 0.11), respectively. In the greater than10 mg/L CRP group treated with etanercept, the ASAS20 response, ASAS40 response, ASDAS-CRP, and ASDAS-ESR outcomes were 74% (P = 0.02), 68% (P = 0.003), 82% (P = 0.005), and 50% (P = 0.001), respectively.
Although there are reduced ASAS20 and ASAS40 response rates in the groups with baseline CRP less than 10 mg/L, there remain clinically relevant responses when the composite outcome measures ASDAS-CRP or ASDAS-ESR were used, and this should be considered when deciding on thresholds for reimbursement.
生物制剂对基线C反应蛋白（CRP）水平不同的患者显示出明显不同的反应率。在此，我们确定非放射学轴向脊柱关节炎（nr-axSpA）患者根据其基线CRP水平分层后使用依那西普的反应。
EMBARK试验是一项关于依那西普治疗nr-axSpA的3期随机双盲安慰剂对照研究。主要终点是双盲期结束时第12周的国际脊柱关节炎评估协会（ASAS）40。该试验招募了符合轴向脊柱关节炎ASAS标准的患者，并对所有患者进行了骶髂关节磁共振扫描。在这项事后分析中，我们根据基线C反应蛋白（CRP）水平低于5mg/L、5mg/L至10mg/L和高于10mg/L分析结果。临床试验结果数据通过Vivli平台获取。
在接受依那西普治疗的CRP水平低于5mg/L组中，ASAS20反应、ASAS40反应、强直性脊柱炎疾病活动评分-CRP（ASDAS-CRP）和ASDAS-红细胞沉降率（ESR）结果分别为49%（P=0.84）、26%（P=0.14）、42%（P=0.002）和44%（P=0.006）。在接受依那西普治疗的CRP水平为5至10mg/L组中，ASAS20反应、ASAS40反应、ASDAS-CRP和ASDAS-ESR结果分别为56%（P=0.99）、31%（P=0.40）、56%（P=0.16）和50%（P=0.11）。在接受依那西普治疗的CRP水平高于10mg/L组中，ASAS20反应、ASAS40反应、ASDAS-CRP和ASDAS-ESR结果分别为74%（P=0.02）、68%（P=0.003）、82%（P=0.005）和50%（P=0.001）。
虽然基线CRP低于10mg/L的组中ASAS20和ASAS40反应率降低，但当使用综合结局指标ASDAS-CRP或ASDAS-ESR时仍存在临床相关反应，在确定报销阈值时应考虑这一点。
