Two Biologics Show No Difference in Axial Spondyloarthritis Radiographic Progression Over 2 Years

Elena Riboldi

June 01, 2023

MILAN, Italy — Secukinumab (Cosentyx) and biosimilar adalimumab-adaz (Hyrimoz) injection proved to have similar efficacy for limiting spinal radiographic progression over a 2-year period in patients with radiographic axial spondyloarthritis (r-axSpA) in the SURPASS study, a phase 3b, randomized controlled trial.

This study, presented at the European Alliance of Associations for Rheumatology (EULAR) 2023 Annual Meeting, represents the first head-to-head trial comparing the effects of two biologic disease-modifying antirheumatic drugs (bDMARDs) in axSpA. Notably, secukinumab and adalimumab-adaz target different pathways as an interleukin-17A (IL-17A) inhibitor and a tumor necrosis factor (TNF) inhibitor, respectively.

Both TNF and IL-17A have been implicated in the pathogenesis of axSpA. Anti-TNF agents and the IL-17A inhibitor secukinumab have demonstrated effectiveness in improving symptoms, signs, and physical function in patients with axSpA and are approved therapies for the disease. However, limited data exist regarding the effect of bDMARDs in slowing radiographic progression, which is a key therapeutic goal in axSpA to prevent irreversible structural damage.

The SURPASS trial, funded by Novartis, enrolled 859 biologic-naive adult patients with moderate-to-severe r-axSpA. Participants were randomly assigned (1:1:1) to receive secukinumab 150 mg (n = 287), secukinumab 300 mg (n = 286), or adalimumab-adaz 40 mg (n = 286). The primary endpoint was the proportion of patients with no radiographic progression at the 2-year mark (week 104). Radiographic progression was defined as a change from baseline in modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS; range 0-72) ≤ 0.5. The radiographic assessments were conducted by three independent evaluators who were blinded to treatment and the chronology of images.

Baseline characteristics indicated that the study population (78.5% male, mean age 42.1 years) had a high risk of radiographic progression. The proportion of patients with no radiographic progression at week 104 was 66.1% in the secukinumab 150-mg arm, 66.9% in the secukinumab 300 mg arm, and 65.6% in the adalimumab-adaz arm. The mean change from baseline in mSASSS was 0.54, 0.55, and 0.72, respectively.

Notably, more than half of the patients (56.9%, 53.8%, and 53.3%, respectively) with at least one syndesmophyte at baseline did not develop new syndesmophytes over the 2-year period. The observed reductions in sacroiliac joint and spinal edema were comparable across all treatment groups. The safety profile of secukinumab and adalimumab-adaz was consistent with their well-established profiles.

Dr Xenofon Baraliakos

No significant differences were observed between the treatment groups in terms of the primary and secondary endpoints. Study presenter and lead author Xenofon Baraliakos, MD, PhD, medical director of the Rheumatism Centre and professor of internal medicine and rheumatology at Ruhr University Bochum, Bochum, Germany, stated, "Anti-TNF therapy has been considered the gold standard treatment for axial spondyloarthritis in terms of slowing or halting radiographic progression. Our aim was to investigate whether other modes of action, such as IL-17 inhibition, achieve the same results. The primary hypothesis was that IL-17 inhibition could be even more effective than TNF blockade. However, our data indicate that secukinumab is at least as good as TNF blockers.

"Several risk factors, including high C-reactive protein [CRP] levels, male gender, high disease activity, and baseline radiographic damage (eg, presence of syndesmophytes), are associated with structural progression," Baraliakos explained. "We performed subgroup analyses and found no differences. This is a positive outcome as it suggests that there is no need to select patients based on either secukinumab or anti-TNF agents."

When making treatment decisions, other factors must be taken into consideration. "Our study specifically examined radiographic progression. The clinical outcomes, indications, and contraindications for anti-TNF agents and secukinumab differ," Baraliakos explained. "For instance, secukinumab may be preferred for patients with psoriasis, while adalimumab is more suitable for those with inflammatory bowel disease. Although these bDMARDs are not interchangeable, they have the same positive effect on radiographic progression."

Not a Definitive Answer About Structural Progression

An open question remains. Alexandre Sepriano, MD, PhD, a rheumatologist at Hospital Egas Moniz and researcher at NOVA Medical School, Lisbon, Portugal, commented: "The study was designed to maximize the chances of detecting a difference, if any, in spinal radiographic progression between secukinumab 150 mg and 300 mg and adalimumab. The included patients had a high risk of progression at baseline; in addition to back pain, they either had elevated CRP or at least one syndesmophyte on spine radiographs. Consequently, baseline structural damage was high (mean mSASSS was 17)."

Dr Alexandre Sepriano

"After 2 years, no difference was observed in the percentage of patients with no progression across the study arms. This finding does not definitively answer whether bDMARDs can modify structural progression or if secukinumab and adalimumab are equally effective in this regard," explained Sepriano, who was not involved in the study. "However, there is good news for patients. Both secukinumab and adalimumab are potent anti-inflammatory drugs that effectively alleviate axial inflammation caused by the disease. This was demonstrated by the reduction in inflammatory scores on MRI in the SURPASS study. It aligns with robust evidence that both IL-17 inhibitors and TNF inhibitors are effective in improving symptoms in individuals with axSpA.

"Researchers continue to make significant efforts to understand how axial inflammation contributes to pathological new bone formation in axSpA," Sepriano continued. "Understanding these mechanisms can guide future research aimed at interfering with disease progression. Furthermore, the use of new methods to quantify structural progression in axSpA, such as low-dose CT, which has shown greater sensitivity to change than traditional methods, can pave the way for new studies with fewer patients and shorter follow-up periods, thereby increasing the likelihood of detecting treatment effects."

Baraliakos has received speaking and consulting fees and grant/research support from AbbVie, Bristol-Myers Squibb, Celgene, Chugai, Merck Sharp & Dohme, Novartis, Pfizer, and UCB. Sepriano has received speaking and/or consulting fees from AbbVie, Novartis, UCB, and Lilly. The trial was sponsored by Novartis.

European Alliance of Associations for Rheumatology (EULAR) 2023 Annual Meeting: Abstract OP0059. Presented May 31, 2023.

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