Sustained remission with methotrexate monotherapy after 22-week induction treatment with TNF-alpha inhibitor and methotrexate in early psoriatic arthritis: an open-label extension of a randomized placebo-controlled trial

BACKGROUND: If TNF inhibitors are initiated in the early stages of psoriatic arthritis, this could potentially modulate disease and therefore allow us to discontinue the TNF inhibitor after achieving remission. OBJECTIVE: To investigate whether remission induced by tumour necrosis factor alpha inhibitor (TNFi) and methotrexate in patients with early psoriatic arthritis is sustained after withdrawal of TNFi. METHODS: Open-label extension of a recently published double-blind, randomized placebo-controlled trial. Patients with psoriatic arthritis fulfilling the CASPAR criteria and with active disease at baseline (swollen and tender joint count ≥ 3) were randomized to either golimumab and methotrexate or matched placebo and methotrexate. Patients in Disease Activity Score (DAS) remission at week 22 continued in the open-label extension on methotrexate monotherapy. The primary end point was the percentage of patients in DAS-CRP remission (DAS < 1.6) at week 50. RESULTS: Eight patients from the original placebo group and 18 patients from the original TNFi group continued in the extension phase. At week 50, 6 out of 8 (75%) patients from the original MTX (methotrexate) group versus 10 out of 18 (56%) patients from the original MTX+TNFi group were in DAS-CRP remission (p = 0.347). Considering the total study population, 6 out of 24 (25%) of the original MTX group versus 10 out of 26 (38.5%) of the original MTX+TNFi group were in DAS remission at week 50 (p = 0.308). CONCLUSIONS: Remission achieved by initial combination treatment with TNFi and methotrexate in early psoriatic arthritis is maintained on methotrexate monotherapy in approximately half of the patients. TRIAL REGISTRATION: Registered at Clinicaltrials.gov with number NCT01871649 on June 7, 2013.