Science from our Sisters

RA Patients Respond to Drug Switching

Most patients who switch from one anti–tumor necrosis factor a (anti–TNF-a) agent to a second for the treatment of RA experience good results, but those who discontinue the second drug usually do so for the same reasons they stopped the first, according to a study in Arthritis & Rheumatism (2007;56(1):13-20).

Anti–TNF-a agents have dramatically improved the management of severe RA. Unfortunately, as many as one-third of the patients who try these drugs derive no benefit from them, due either to inefficacy or intolerable adverse effects (AEs). If the first drug doesn’t work, many patients switch to a second anti–TNF-a agent on the rationale that it might be more effective due to differences in structure and site of action. This study is the first large-scale examination of the results of such a drug swap.

For a mean of 15 months, lead author Kimme Hyrich, MD, PhD, and colleagues at the University of Manchester (England) followed a prospective cohort of 6,739 RA patients drawn from a United Kingdom national registry of new patients starting anti–TNF-a therapy. During that time, 2,360 patients discontinued the initial drug, including 1,864 who discontinued because of lack of effect (n=841; 12%) or AEs (n=1,023; 15%). Of those patients, 503 and 353, respectively, switched to a second drug.

Overall, 73% of patients who switched to a second anti–TNF-a agent were still on the new therapy by the end of follow-up. However, 13% of the patients discontinued the second drug because of inefficacy, and 14% due to an adverse event. The patients who discontinued the second drug tended to do so for the same reasons they discontinued the first, whether that was inefficacy or toxicity.

“These findings suggest that, in those patients who fail to respond to their first agent, either because of an adverse effect or inefficacy, switching to a second anti–TNF agent may be a viable next option for some,” says Dr. Hyrich, clinical lecturer in the arthritis research campaign epidemiology unit at the University of Manchester. “It is also reassuring that the rate of discontinuation for an AE on a second agent was not increased in those patients who switched for inefficacy, suggesting, at least in the short term, that consecutive use of anti–TNF-a­­ agents does not place patients at an increased risk of AEs.”

Norra MacReady is a medical journalist based in southern California.