About Half of Psoriatic Arthritis Patients Have Extended Remission After TNFi Therapy

By Brenda L. Mooney, /alert Contributor
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Is it possible that initiating tumor necrosis factor inhibitors in the early stages of psoriatic arthritis could potentially modulate disease and allow clinicians to discontinue the TNF inhibitor after achieving remission? This question was addressed  by researchers in a recent Arthritis Research & Therapy study.

University of Amsterdam-led researchers sought to investigate whether remission induced by tumor necrosis factor alpha inhibitor (TNFi) and methotrexate in patients with early psoriatic arthritis is sustained after withdrawal of TNFi.

Psoriasis remission. Source: Getty

The study was an 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. 

The study team continued patients in Disease Activity Score (DAS) remission at week 22 on methotrexate monotherapy. The primary end point was defined the percentage of patients in DAS-CRP remission (DAS < 1.6) at week 50.

According to results, 8 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 vs. 10 out of 18 (56%) patients from the original MTX+TNFi group were in DAS-CRP remission (P = 0.347). 

In terms of the total study population, 6 out of 24 (25%) of the original MTX group vs. 10 out of 26 (38.5%) of the original MTX+TNFi group were in DAS remission at week 50 (P = 0.308).

“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,” the authors concluded.

A British study also looked at the long-term effectiveness of TNFi therapy in patients with PsA. Results were published in Rheumatology Advances in Practice

Researchers from Addenbrookes Hospital in Cambridge and colleagues sought to describe patterns of TNFi therapy and treatment responses in PsA patients treated in UK clinical practice.

The multicenter, retrospective, observational cohort study of patients treated with TNFi for PsA with 3 or more years of follow-up from first TNFi initiation (observation period) was carried out in 11 UK National Health Service hospitals. Researchers collected data concerning baseline patient characteristics, PsA-related treatment pathways and TNFi treatment responses, i.e., PsA response criteria components: swollen/tender joint counts, physician and patient global assessments.

Mean age of the 141 patients was 50.3 (s.d.: 12.1) and half were male). During a median observation period of 4.5 (range: 3.4-5.5) years, patients received a median of one (range: one to five) TNFi. 

The authors said 12-week response rates for first TNFi (where available) were:

  • 80% (n = 64/80) for swollen joint counts, 

  • 79% (n = 63/79) for tender joint counts, 

  • 79% (n = 37/47) for physician global assessments, 

  • 69% (n = 41/59) for patient global assessments and 

  • 79% (n = 37/47) for PsA response criteria. 

At the end of the observation period, the proportion of patients remaining on first, second, third and fourth/fifth TNFi were 56, 15, 5 and 3%, respectively. In fact, the researchers emphasized, 21% of patients permanently discontinued TNFi therapy.

“Long-term TNFi therapy is generally well tolerated and may be effective; however, after initial TNFi failure, there appears to be progressively less benefit and more adverse effects with successive TNFi switches,” the authors concluded. “Strategies are needed for effective therapy for PsA beyond the first TNFi failure.”