To re-analyse the clinical outcomes and interferon (IFN) activity data from the JOQUER trial, a phase III trial investigating hydroxychloroquine (HCQ) in patients with primary Sjögren’s syndrome (pSS), after stratifying patients into putative pathobiological subgroups utilizing the Newcastle Sjögren’s Stratification Tool (NSST) based on patient-reported symptoms of dryness, pain, fatigue, anxiety and depression. This evidence concerns the gene IFNA1 and Sjogren syndrome.