A novel IL-17A inhibitor, QX002N, delivered rapid and clinically meaningful improvements in disease activity, function, and MRI-detected inflammation in patients with radiographic axial spondyloarthritis (r-axSpA), according to new results from a pivotal phase III trial and presented at ACR Convergence. 

“QX002N is a novel high-affinity monoclonal antibody (mAb) that selectively targets IL-17A,” the investigators wrote. “We conducted the phase Ⅲ pivotal study to confirm the efficacy and safety of QX002N in r-axSpA patients.” The study was also reported in Arthritis & Rheumatology.

In this double-blind, placebo-controlled study, 641 adults with active r-axSpA were randomized 1:1 to receive QX002N (160 mg subcutaneously every 4 weeks) or placebo through week 16. All patients transitioned to open-label QX002N through week 52. The primary endpoint was ASAS40 response at week 16; secondary endpoints included ASAS20 and changes in SPARCC MRI scores of the sacroiliac joints (SIJ) and spine.

At week 16, 40.4% of QX002N-treated patients achieved ASAS40 compared with 18.9% in the placebo group (P<.0001). ASAS20 responses also favored QX002N (65.2% vs 41.3%). Improvements were consistent across function and quality-of-life measures.

Among MRI-evaluable patients (~31% of total), QX002N produced a greater reduction in SPARCC SIJ scores from baseline to week 16 (–6.2 vs –2.3; P=.0262) and SPARCC spine scores (–8.1 vs –1.4; P=.0005), indicating a measurable anti-inflammatory effect.

Treatment-emergent adverse events occurred in 75.8% of QX002N patients and 71.2% of placebo recipients, mostly CTCAE Grade 1 or 2. Serious adverse events were infrequent (2.2% vs 0.9%, respectively).

“QX002N provided significant improvements in the symptoms and signs, as well as marked reduction in inflammation of the spinal and SIJ as measured by MRI in r-axSpA patients, when compared to placebo at week 16," concluded study authors. "The safety of QX002N was tolerable.”

Zeng X, Zhang S, Liu S, et al. Effect of QX002N on clinical and radiographic outcomes in ankylosing spondylitis: results from a phase III randomized, double-blind, placebo-controlled study [abstract]. Arthritis Rheumatol. 2025; 77 (suppl 9). https://acrabstracts.org/abstract/effect-of-qx002n-on-clinical-and-radiographic-outcomes-in-ankylosing-spondylitis-results-from-a-phase-iii-randomized-double-blind-placebo-controlled-study/. Accessed October 17, 2025.