New Oral Option for axSpA: Filgotinib for Radiographic and Non-Radiographic Disease Save

The Janus kinase inhibitor (JAKi) class has been increasingly used in the management of axial spondyloarthritis (axSpA) over the past five years, offering effective oral alternatives to injectable biologics. 

But are all JAK inhibitors the same? 

Filgotinib, a JAK1-preferential inhibitor, takes a selective approach that may deliver the anti-inflammatory efficacy of pan-JAK blockade while reducing the breadth of immunological disruption associated with inhibiting JAK2 and JAK3. The Phase 3 OLINGUITO programme, presented in full at EULAR 2026 (Abstract OP234) provides the phase 3 evidence for Filgotinib across both radiographic (r-axSpA) and non-radiographic (nr-axSpA) disease.

OLINGUITO consisted of two parallel, randomised, double-blind, placebo-controlled Phase 3 studies. Study A enrolling 258 patients with r-axSpA and Study B enrolling 237 patients with nr-axSpA. Eligible patients had established ASAS-classified axSpA and inadequate response or intolerance to conventional treatments including NSAIDs. The study included both biologic-naïve patients and those with prior bDMARD exposure. Approximately 20% of participants were aged 65 years or older and/or carried pre-specified risk factors, an important subgroup historically underrepresented in axSpA trials.

Patients were randomised 1:1 to Filgotinib 200 mg once daily or placebo for 16 weeks, stratified by bDMARD status and CRP level. After Week 16, all patients entered an open-label extension to Week 52. The primary endpoint in both studies was ASAS40 response at Week 16.

The primary endpoint was met in both studies. In r-axSpA, 39.5% of Filgotinib-treated patients achieved ASAS40 at Week 16 compared with 20.9% on placebo,  a difference of 18.6 percentage points (p = 0.001). In nr-axSpA, 34.5% vs 17.8% achieved ASAS40 (difference 16.7%, p = 0.003). Responses appeared as early as Week 1 and continued to improve throughout the 52-week observation period, with the majority of Week-16 responders maintaining their response to Week 52.

One of the clinically significant findings in OLINGUITO was the striking separation in the bDMARD inadequate-responder subgroup. In r-axSpA patients who had previously failed a biologic, ASAS40 was achieved by 48.4% on Filgotinib versus only 14.3% on placebo,  a difference of over 34 percentage points. In nr-axSpA bDMARD-IR patients, 30.8% on Filgotinib achieved ASAS40 compared with none on placebo (0%). These numbers suggest that Filgotinib retains robust efficacy even after biologic failure, a clinically critical scenario given the growing population of patients who have cycled through one or more biologics.

Beyond clinical response, OLINGUITO demonstrated significant improvements in MRI-assessed sacroiliac joint inflammation (SPARCC SIJ scores) with Filgotinib in both studies at Week 16  an important signal that the drug is reducing objective inflammatory burden in the target tissue, not merely blunting symptom scores. ASDAS (Ankylosing Spondylitis Disease Activity Score) improvements were also significantly greater with Filgotinib in both populations. Functional improvements (BASFI) and quality of life (ASQoL) were significantly better in r-axSpA. In nr-axSpA, these endpoints were numerically improved but did not formally reach significance, likely reflecting smaller numbers and a less severe functional baseline.

OLINGUITO positions Filgotinib as a further oral option for both radiographic and non-radiographic axSpA across bDMARD-naïve and bDMARD-experienced patients. Its JAK1-preferential profile has been associated with a more favourable haematological safety signal compared with less selective JAK inhibitors in other indications, though the direct clinical relevance of this selectivity in axSpA will require longer-term and larger safety datasets to fully characterise. With no cases of herpes zoster, MACE, non-melanoma skin cancer or thrombotic events in the 16-week placebo-controlled period, the initial safety profile is reassuring. For clinicians managing patients with active axSpA who prefer or require an oral agent  whether at first advanced therapy or after biologic failure OLINGUITO provides Phase 3 evidence that Filgotinib is a meaningful addition to the treatment toolbox.