Secukinumab on par with adalimumab biosimilar in r-axSpA

Treatment with secukinumab (SEC) shows no significant difference with adalimumab biosimilar (SDZ-ADL) in spinal radiographic progression, which remains low over 2 years, among patients with radiographic axial spondyloarthritis (r-axSpA), according to a phase IIIb study presented at EULAR 2023.

In addition, “[s]afety was consistent with the well-established safety profiles of SEC and SDZ-ADL,” said lead study author and presenter Xenofon Baraliakos from Rheumazentrum Ruhrgebiet, Rheumatology, in Herne, Germany.

He noted that data on the effect of biologics in slowing radiographic progression in patients with r-axSpA were limited. Specifically, 2-year data from MEASURE 1 showed low radiographic progression with SEC. [Ann Rheum Dis 2017;76:1070-1077]

Baraliakos and his team then conducted this randomized phase IIIb study to compare the effect of SEC vs SDZ-ADL on spinal radiographic progression from SURPASS, the first head-to-head study in r-axSpA. [Clin Drug Investig 2020;40:269-278; Arthritis Rheumatol 2022;74 (suppl 9)]

Bio-naïve patients with active r-axSpA with a Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) ≥4, spinal pain score ≥4 (range 0–10), total back pain score ≥40 mm (range 0–100 mm), and high sensitivity C-reactive protein (hs-CRP) ≥5 mg/L, or ≥1 syndesmophyte(s) on spinal radiograph were randomized to receive either SEC (150/300 mg; dose-blinded) or SDZ-ADL (40 mg; open label).

Three independent central readers who were blinded to treatment and chronology of images reviewed the radiographs and magnetic resonance imaging (MRI).

Similar efficacy

A total of 859 patients (mean age 42.1 years) received SEC (150 mg: n=287; 300 mg: n=286) or SDZ-ADL (n=286), of which 78.5 percent were male. Their modified Stoke AS Spinal Score (mSASSS) was 16.6, BASDAI was 7.1, and hs-CRP was 20.4 mg/L. Of the patients, 73 percent had ≥1 syndesmophyte(s). This population had an increased risk of radiographic progression. [EULAR 2023, abstract OP0059]

Cumulative distribution of change from baseline (CFB) in mSASSS at week 104 was comparable across treatment arms. The proportion of patients with no radiographic progression was 66.1 percent with SEC 150 mg, 66.9 percent with SEC 300 mg, and 65.6 percent with SDZ-ADL, while the mean CFB-mSASSS was 0.54, 0.55, and 0.72, respectively.

At week 104, 56.9 percent of patients on SEC 150 mg, 53.8 percent of those on SEC 300 mg, and 53.3 percent of those on SDZ-ADL, with a baseline ≥1 syndesmophyte(s), did not develop new syndesmophyte(s)

In the MRI subset (n=418), the corresponding mean sacroiliac joint scores at baseline and week 16 were 2.54 and 0.98 (SEC 150 mg), 1.96 and 0.92 (SEC 300 mg), and 1.59 and 0.38 (SDZ-ADL). Additionally, spine scores were 3.50 and 1.79, 2.56 and 1.25, and 3.00 and 0.71, respectively.

In subgroup analysis by baseline syndesmophytes and CRP status, “[s]pinal radiographic progression over 2 years was low with no notable difference between SEC and SDZ-ADL arms regardless of the presence or absence of specific predictive factors for progression (syndesmophytes/elevated CRP),” according to the researchers. [EULAR 2023, abstract POS1115]

“Expectedly, patients from subgroups without predictive factors had lower rates of radiographic progression,” they added.

Baseline radiographic damage (presence of syndesmophytes) and elevated CRP levels were both predictive of radiographic progression in patients with r-axSpA. [Arthritis Rheum 2012;64:1388-9138]