Tofacitinib provides 'meaningful reduction' in inflammation for patients with ankylosing spondylitis

Treatment with tofacitinib improved sacroiliac joint and spine scores among patients with ankylosing spondylitis and resulted in more patients achieving minimum clinically important differences compared with placebo, according to findings presented at the American College of Rheumatology Annual Meeting.

Patients who achieved minimum clinically important differences (MCID) for MRI inflammation experienced greater clinical response rates.

Walter Maksymowych

“[MCID] for Spondyloarthritis Research Consortium of Canada MRI sacroiliac joint and spine scores are ≥ 2.5 and ≥ 5, respectively,” researchers wrote. “We assessed whether minimum clinically important differences in sacroiliac joints and spine can discriminate between tofacitinib (Xeljanz, Pfizer) and placebo in patients with ankylosing spondylitis, and whether this is concordant with clinical responses.”

Walter Maksymowych, MD, FRCPC, FACP, of the Department of Medicine at the University of Alberta, and colleagues randomly assigned 207 adult patients who met modified New York ankylosing spondylitis criteria 1:1:1:1 to placebo or tofacitinib at 2 mg, 5 mg or 10 mg twice daily for 12 weeks in the 16-week, double-blind, dose-ranging phase 2 study.

Clinical response endpoints in the post-hoc analysis included Assessment of Spondyloarthritis International Society (ASAS) 20 and ASAS40 response rates, Ankylosing Spondylitis Disease Activity Score (ASDAS) major improvement (ASDAS MI) and ASDAS of less than 1.3, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Bath Ankylosing Spondylitis Functional Index (BASFI). Patients who achieved MCID in sacroiliac joints, the spine or both in the tofacitinib and placebo groups were summarized according to observed data; pooled tofacitinib vs. placebo groups were compared using Fisher’s exact test. The researchers assessed concordance between achieving MCID and clinical responses at week 12 and compared responses between patients who did and patients who did not achieve MCID.

Researchers assessed MRI data from 164 patients. Baseline demographics were generally similar between treatment groups and representative of patients with ankylosing spondylitis, according to the study results.

All doses of tofacitinib resulted in improvements in sacroiliac joint and spine scores compared with placebo. The number of patients who attained MCID in the sacroiliac joint and spine was approximately three-times greater in the pooled tofacitinib group compared with placebo (P < .05 for sacroiliac joints; P < .01 for spine). Reaching MCID in both the sacroiliac joints and the spine was associated with clinical response.

Among patients treated with tofacitinib, ASAS20, ASAS40, ASDAS MI and ASDAS of less than 1.3 responses were more likely in those who achieved MCID in the sacroiliac joints, spine or both compared with those who did not. Patients treated with tofacitinib who achieved MCID in the sacroiliac joints also experienced greater improvements in BASDAI and BASFI scores, as well as back pain compared with those who did not.

Patients with ankylosing spondylitis treated with tofacitinib “experienced clinically meaningful reductions in axial MRI inflammation, [and] patients achieving MCID for MRI inflammation had increased clinical response rates,” researchers wrote. – by Julia Ernst, MS

Reference:

Maksymowych W, et al. Abstract 1044. Presented at: The American College of Rheumatology Annual Meeting; Nov. 11-16, 2016; Washington.

Disclosures: Maksymowych reports associations with AbbVie, Amgen, Boehringer-Ingelheim, Celgene, Eli-Lilly, Janssen, Merck, Novartis, Pfizer, Sanofi and UCB.