Concerns have been raised that randomized placebo-controlled trials (RCTs) in non-radiographic axial spondyloarthritis (nr-axSpA) might be failing to identify patients that best show differences in clinical response rates between those receiving active drug and those receiving placebo therapies; in addition, some studies might even be showing spurious differences in responses to TNF and IL-17 inhibitor therapies. In particular, the most recent phase III RCTs in nr-axSpA have reported variable and generally lower response rates than observed in phase III trials of patients with ankylosing spondylitis and in trials conducted a decade ago in patients with early axSpA who were selected on the basis of axial inflammation evident on MRI scans. We argue that these observations at least partly reflect an RCT design that does not take full advantage of MRI to select patients who are responsive to therapy because the current MRI-based inclusion criteria cannot identify patients with axSpA with sufficient specificity. We propose that future studies should be designed using revised patient inclusion criteria based on expanded MRI evaluation and the application of data-driven definitions of a positive MRI for inflammatory and structural lesions typical of axSpA reported in an international multicentre analysis of MRI scans from the Assessment of SpondyloArthritis International Society (ASAS) classification cohort.

有人担心，针对非放射学中轴​​型脊柱关节炎 (nr-axSpA) 的随机安慰剂对照试验 (RCT) 可能无法确定最能显示接受活性药物治疗的患者和接受安慰剂治疗的患者之间临床反应率差异的患者；此外，一些研究甚至可能显示出对 TNF 和 IL-17 抑制剂治疗反应的虚假差异。特别是，最近针对 nr-axSpA 的 III 期随机对照试验报告的反应率可变且普遍低于强直性脊柱炎患者的 III 期试验和十年前针对早期 axSpA 患者进行的试验，这些患者是根据MRI 扫描中明显的轴向炎症。我们认为，这些观察结果至少部分反映了 RCT 设计没有充分利用 MRI 来选择对治疗有反应的患者，因为目前基于 MRI 的纳入标准无法以足够的特异性识别 axSpA 患者。我们建议，未来的研究应该使用修订后的患者纳入标准进行设计，该标准基于扩展的 MRI 评估，以及应用数据驱动的阳性 MRI 定义对来自评估的 MRI 扫描进行的国际多中心分析中报告的典型 axSpA 炎症和结构性病变的数据驱动定义脊柱关节炎国际协会 (ASAS) 分类队列。