Can more than one TNF inhibitor be tried in a patient? Any guidelines for switching?
Most physicians and patients feel that at least a 50% overall clinical response is necessary to justify the cost and risk of using a TNF inhibitor. At least 50% of patients with RA, AS, or PsA may not achieve this response or will develop an intolerance to the first TNF inhibitor they are put on. Although controversial, many physicians will try a second TNF inhibitor. The effectiveness of switching TNF inhibitors and the “rules” for switching can be summarized as follows:
- • Patients who fail to respond to the first TNF inhibitor (primary failures) are less likely to get a good response to a second TNF inhibitor compared with patients who initially responded to a TNF inhibitor and then lose that response (secondary failures) or who had to stop the TNF inhibitor as a result of an adverse event (intolerance). Only 4% to 5% of primary failures will get a good response to a second TNF inhibitor compared with 27% to 30% of patients who had secondary failure/intolerance.
- • Patients who had an adverse event to their first TNF inhibitor are more likely (2–3×) to develop an adverse event to a second TNF inhibitor.
- • To increase the chance of a response in a primary failure patient, choose a second TNF inhibitor which is a different molecule. For example, if the patient fails ADA (monoclonal antibody), put them on ETN (soluble receptor) and vice versa. Usually this is not successful and switching from a TNF inhibitor to a bDMARD with a different mechanism of action is usually the best approach in patients who are primary TNF inhibitor failures.
- • Patients who are secondary failures or have developed adverse events to a TNF inhibitor (especially INF) may have developed neutralizing antibodies, and switching to a second TNF inhibitor of any type can be beneficial.
- • Patients who have failed two TNF inhibitors should probably not be tried on a third.
