The ABILITY-2 study, described previously (ClinicalTrials.gov, NCT01064856),2 (link) was a phase III, multicentre, randomised, double-blind, placebo-controlled trial in patients with active non-psoriatic pSpA. Patients were randomised 1:1 to receive adalimumab (AbbVie, North Chicago, Illinois, USA) 40 mg every other week or placebo during a 12-week double-blind period,2 (link) followed by an open-label period of up to 3 years of adalimumab treatment. Eligible patients were aged ≥18 years, fulfilled the ASAS criteria for pSpA1 (link) and had pSpA symptoms for ≥3 months before the study baseline visit. Patients had active disease, a score ≥40 mm on a 0–100 mm visual analogue scale (VAS) for Patient Global Assessment of disease activity (PtGA) and Patient Global Assessment of pain (PtGA-pain) and an inadequate response to ≥2 non-steroidal anti-inflammatory drugs (NSAIDs) or intolerance to or contraindication for NSAIDs. The study was performed in accordance with the International Conference on Harmonisation Guidelines for Good Clinical Practice and the Declaration of Helsinki.