BARCELONA, Spain—Switching immediately from a TNF-inhibitor to abatacept (ABA) (Orencia®, Bristol-Myers Squibb Co) without an intervening washout period is safe, according to Michael Schiff, MD, medical director at the Denver Arthritis Clinic, in Colorado.1 At the 2007 EULAR meeting Dr. Schiff reported outcomes in a subgroup analysis comparing patients who had switched immediately from a TNF-inhibitor to ABA with those who had switched after 2 months or more after discontinuing TNF-inhibitors. The analysis included 842 US patients from the international, 6-month, open-label, phase IIIb ARRIVE (Abatacept Researched in Rheumatoid arthritis patients with an Inadequate antiTNF response to Validate Effectiveness) trial of 1285 patients with active rheumatoid arthritis (RA) and an inadequate response to >e;3 months of antiTNF therapy.

"The safety of abatacept was unaffected by whether these patients had undergone a wash-out period from anti-TNF therapy. This supports direct switching to abatacept from anti-TNF therapy as an option in clinical practice." Michael Schiff, MD
"The safety of abatacept was unaffected by whether these patients had undergone a washout period from antiTNF therapy. This supports direct switching to abatacept from antiTNF therapy as an option in clinical practice," concluded Dr. Schiff.

The main study objective was to assess the clinical safety and tolerability of ABA in a clinical setting when antiTNF inadequate responders are switched to ABA without a washout period. "This was designed to look like regular clinical practice," Dr. Schiff said. "We asked whether, when a patient is flaring, with an inadequate response to TNF-inhibition, it is necessary to put them through a TNF washout period before switching to abatacept."

Notably, the trial did not exclude patients with positive tuberculosis (TB) skin tests, provided they had completed treatment for TB.

The patients had either discontinued antiTNF therapy >e;2 months before screening owing to a lack of clinical response or an inadequate response and persistent disease activity (prior users, n = 370); or had received antiTNF therapy within 2 months of screening, without a clinical response, or had an insignificant response and a persistent DAS28 (C-reactive protein [CRP]) score of >e;5.6 (current users, n = 472). Patients were also considered if they had discontinued antiTNF therapy primarily for safety reasons.

The current users were switched to ABA at the time of their next scheduled antiTNF dose. Patients received a fixed dose of ABA (~10 mg/kg, according to weight range) on days 1, 15, and 29, and every 4 weeks thereafter, plus stable background nonbiologic DMARD therapy.

Dr. Schiff reported the frequency of adverse events (AEs), serious AEs (SAEs), discontinuations due to AEs/SAEs, infections, neoplasms, and deaths were similar in both prior and current groups, as were serious infections (2.2 vs 2.3%, respectively). The most frequent serious infection was pneumonia in four current patients and in two prior patients (0.8% vs 0.5%). "There were no serious opportunistic infections, including TB, in either group," Dr. Schiff said.

One death due to congestive heart failure occurred in the prior users group, but it was not considered related to ABA therapy.

Dr. Schiff commented that the switch to ABA produced DAS28 remission in 16% of these TNF-inhibitor-resistant patients.

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Reference

1. Schiff M, Pritchard C, Teng J, et al. The safety of abatacept in patients with active rheumatoid arthritis and an inadequate response to anti-TNF therapy: results from the ARRIVE trial. Presented at: EULAR 2007 Meeting; June 13-16, 2007; Barcelona, Spain. Abstract OP0121.