OLINGUITO: Filgotinib Meets Phase 3 Primary Endpoint in r/nr-axSpA, With Xenofon Baraliakos, MD, PhD

Filgotinib 200 mg once daily, an oral JAK1 preferential inhibitor, significantly improved disease activity versus placebo at week 16 in both radiographic (r-axSpA) and non-radiographic (nr-axSpA) axial spondyloarthritis, meeting the primary endpoint of both studies within the phase 3 OLINGUITO trial, according to results presented at the European Alliance of Associations for Rheumatology (EULAR), held June 3-6 in London, United Kingdom.^1,2

During the meeting, RheumatologyLive caught up with Xenofon Baraliakos, MD, Medical Director of the Rheumazentrum Ruhrgebiet and Professor of Internal Medicine and Rheumatology at Ruhr University Bochum, Herne, Germany, and current President of EULAR, who served as lead investigator and presented the data at the meeting. OLINGUITO (NCT05785611) comprised 2 international, randomized, double-blind, placebo-controlled studies enrolling adults with established axSpA per ASAS classification criteria who had an inadequate response or intolerance to conventional treatments including NSAIDs. Patients were randomized 1:1 to filgotinib 200 mg or placebo once daily through week 16, stratified by bDMARD status and hs-CRP level. After week 16, all patients entered an open-label period receiving filgotinib 200 mg once daily through week 52, except those aged ≥65 years and/or with prespecified risk factors, who received the lowest effective dose based on clinical response (responders: 100 mg; non-responders: 200 mg until response, then reduced to 100 mg). Approximately 20% of the overall study population fell into this lower-dose category.¹

A total of 258 patients with r-axSpA and 237 with nr-axSpA were enrolled. Baseline characteristics were comparable between arms within each study. In the r-axSpA study, mean age was 43.4 (standard deviation [SD], 10.9) years for filgotinib (n = 129) and 42.2 (SD, 11.5) for placebo (n = 129); mean ASDAS was 3.6 (SD, 0.9) and 3.5 (SD, 0.7), and mean BASDAI was 6.7 (SD, 1.3) in both arms. In the nr-axSpA study, mean age was 41.8 (SD, 12.4) and 40.1 (SD, 11.5) years, mean ASDAS was 3.6 (SD, 0.8) and 3.4 (SD, 0.8), and mean BASDAI was 6.9 (SD, 1.2) and 6.5 (SD, 1.4) for filgotinib and placebo, respectively.¹

For the primary endpoint of ASAS40 at week 16, filgotinib was superior to placebo in both studies. In r-axSpA, ASAS40 was achieved by 39.5% versus 20.9% (treatment difference 18.6% [95% CI, 7.6–29.6]; P = .001), and in nr-axSpA by 34.5% versus 17.8% (treatment difference 16.7% [95% CI, 5.7–27.6]; P = .003).¹ Responses emerged as early as week 1 and continued to improve through week 52. Among patients achieving ASAS40 at week 16, 84.6% in the r-axSpA group and 78.0% in the nr-axSpA grup maintained their response through week 52. Placebo patients who crossed over at week 16 demonstrated rapid catch-up, reaching response rates comparable to the filgotinib group within 4 to 6 weeks.¹

In the bDMARD-inadequate response (IR) subgroup, week 16 ASAS40 response rates were particularly pronounced: 48.4% versus 14.3% in r-axSpA (treatment difference 34.1% [95% CI, 12.3–56.0]) and 30.8% versus 0% in nr-axSpA (treatment difference 30.8% [95% CI, 13.0–48.5]) for filgotinib versus placebo.¹

"We are lacking JAK inhibitors in the field of axial spondyloarthritis — we have at the moment 2 of them approved, one not entirely in both indications," Baraliakos said. "There is clear need for JAK inhibition, for an oral drug in axial spondyloarthritis, and from a study design like the one we had in OLINGUITO."

For multiplicity-adjusted secondary endpoints at week 16, filgotinib produced significantly greater improvements versus placebo in ASDAS, SPARCC MRI sacroiliac joint (SIJ) scores, BASFI, and ASQoL in r-axSpA (all P <.001 to P = .007), and in ASDAS and SPARCC MRI SIJ in nr-axSpA (both P <.001). BASMI improvement was numerically but not statistically significantly greater with filgotinib in both studies. All improvements in ASDAS, SPARCC MRI SIJ, BASFI, BASMI, and ASQoL were either maintained or further improved through week 52.¹

Safety through week 52 was consistent with the known filgotinib profile.1,2 In the double-blind period, 2 serious treatment-related treatment-emergent adverse events (TEAEs) — both cases of pneumonia — occurred in the filgotinib group (1 in each study). Two malignancies were reported in the filgotinib group during the double-blind period (essential thrombocythemia in r-axSpA; melanoma in nr-axSpA), neither considered treatment-related. No cases of herpes zoster, MACE, non-melanoma skin cancer, or thrombotic events were reported in the filgotinib group through week 16. During the open-label period, 1 case of acute myocardial infarction (nr-axSpA), 3 cases of herpes zoster, and 2 additional malignancies were reported, including 1 treatment-related case of prostatic adenocarcinoma. No new safety signals were identified.¹

Baraliakos’ disclosures include AbbVie, Advanz, Alexion, Alfasigma S.p.A., Amgen, AstraZeneca, BMS, CESAS, Celltrion, and Clarivate.

References

1. Baraliakos X, Maksymowych WP, Navarro-Compán V, et al. Filgotinib significantly improves disease activity in patients with active axial spondyloarthritis: primary results from the phase 3 OLINGUITO trial [abstract OP0234]. Ann Rheum Dis. 2026;85(suppl 1). doi:10.1136/annrheumdis-2026-eular.B.1136

2. Alfasigma S.p.A. Alfasigma presents first data on filgotinib from the phase 3 OLINGUITO trial in axial spondyloarthritis at EULAR 2026 [press release]. May 27, 2026. https://www.businesswire.com/news/home/20260526373154/en/Alfasigma-presents-first-data-on-filgotinib-from-the-Phase-3-OLINGUITO-trial-in-axial-spondyloarthritis-at-EULAR-2026