Long-term abatacept treatment for 48 weeks in patients with primary Sjogren's syndrome: The open-label extension phase of the ASAP-III trial

Objective: To investigate treatment efficacy of long-term abatacept treatment in pSS patients. Methods: The single-centre ASAP-III trial consisted of two phases: the randomised, double-blind, placebo-controlled phase (1:1 randomisation) from baseline to week 24, of which results have been published previously, and the open-label extension phase from week 24 to 48, in which all patients received abatacept. Main inclusion criteria were fulfilment of the AECG criteria, positive gland biopsy, disease duration <= 7 years and ESSDAI >= 5. Long-term treatment effects of abatacept on clinical, patient-reported, glandular and laboratory outcome measures were assessed in patients treated with abatacept from baseline to week 48. Furthermore, Composite of Relevant Endpoints for Sj_ogren's Syndrome (CRESS) response (response on >= 3 of 5 items) was analysed. Results: In patients on abatacept treatment for 48 weeks (n = 40), median ESSDAI improved from baseline 14.0 (IQR 9.0 - 16.8) to 4.0 (2.0 - 8.0) at week 48 (p < 0.001), with 50% of patients reaching low disease activity (ESSDAI < 5) at week 48. Median ESSPRI improved from 7.0 (IQR 5.4-7.7) to 5.0 (3.7-6.7) (p < 0.001). Significant improvement was also seen in dry eye and laboratory tests. Combining response at multiple clinically relevant items, 73% of patients were CRESS responders at week 48. Additional improvement was seen between week 24 and week 48 of abatacept treatment. Conclusion: In the open-label extension phase of the ASAP-III trial, improvement was seen up to 48 weeks of abatacept treatment in clinical, patient-reported, dry eye and laboratory outcomes. The majority of patients were CRESS responders at week 48. (c) 2022 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)