Patients with psoriatic arthritis who began taking disease-modifying antirheumatic drugs often changed regimens soon afterward, especially if they had started with nonbiologic treatments, researchers reported online in Arthritis Research and Therapy.
Only 31% of patients who started methotrexate or another nonbiologic disease-modifying antirheumatic drug (DMARD) for psoriatic arthritis stayed with their initial treatment for the next year, compared with 54% of patients who started on a biologic DMARD such as etanercept, infliximab, or golimumab, said Dr. Huabin F. Zhang at Celgene in Summit, N.J., and his associates.
The researchers analyzed U. S. health care claims data for 1,698 adults with psoriatic arthritis who were started on oral nonbiologic DMARDs and for 3,263 patients started on biologic DMARDs. In all, 69% of patients who started nonbiologic DMARDs and 46% of those who started biologic DMARDs discontinued, switched, or added on to their treatment within a year of starting therapy, they found. Patients most often switched to or added a biologic as opposed to a nonbiologic DMARD, the investigators said. Those who started on nonbiologics primarily took methotrexate, and “patient persistence with treatment was generally low and relatively brief,” they said. Other studies have shown that use of nonbiologic DMARDs “erodes rapidly and progressively over time,” they said (Arthritis Res. Ther. 2014 Aug. 22 [doi:10.1186/s13075-014-0420-5]).
Health insurance companies often require patients to take one or two nonbiologics before they will reimburse for a biologic DMARD, which could partially explain these findings, the researchers said. But the retrospective observational study did not capture data on side effects, safety concerns, or other reasons for treatment changes, they noted.