PsA Patients Switching Drugs Fast, Favoring Biologics

Zhang H, Gauthier G, Hiscock R, Curtis J. Treatment patterns in psoriatic arthritis patients newly initiated on oral nonbiologic or biologic disease-modifying antirheumatic drugs. Arthritis Research & Therapy (2014) 16:420 doi:10.1186/s13075-014-0420-5 

Whichever treatment choice you and your newly diagnosed patient with psoriatic arthritis (PsA) have made, it probably won't last more than a few months. That's the upshot of a large retrospective study involving almost 5,000 patients in a large US insurance database.

These real-world results raise some interesting questions about the practicality of advice in current guidelines.

A switch is most likely if your first choice is a non-biologic disease-modifying drug (DMARD). Among patients receiving non-biologic DMARDs, 69% either switched or quit their medication a few months after beginning treatment, the data show. After a year, only around a third of the patients remained on their initial nonbiologic DMARD, while a little over half of those who started on biologics were still on their first-choice therapy.

Of the 1,698 patients starting on conventional oral DMARDs (most of them on methotrexate, MTX), 83% discontinued their initial medication. Among these, 29% later tried a different medication (two-thirds of them choosing a biologic) and 25% started again, adding another drug, in most cases also a biologic. Median time to stopping the nonbiologic: less than 3 months.

Among the 3,263 who began with biologic DMARDs, 46% had one or more changes in therapy. All of those patients quit their first biologic, most switching to another biologic DMARD (92%) and 7% adding a nonbiologic drug. That switch usually took place in just under four months.

Among the subgroup who started treatment with MTX (n=1,217), 65% had at least one therapy change. Most simply quit medication. Almost a third chose to add another therapy, and one-fourth switched, mostly to biologics (73%). Median time to treatment change in this group was three months.

The real-world pattern in the study--showing that two-thirds of patients start off with a biologic DMARD--runs counter to the stepwise approach advocated by the European League Against Rheumatism (EULAR) and the American Academy of Dermatology.

Those recommendations favor beginning with non-steroidal antiinflammatory drugs (NSAIDs) or intra-articular corticosteroids in mild PsA and, if the disease isn’t well controlled within three months, progressing to conventional oral DMARDs like MTX. The guidelines suggest trying biologic drugs like adalimumab (Humira) only if non-biologic DMARDs fail to control symptoms.

Why were the patients in this insurance database so quick to change medications? Were they most often dissatisfied with lack of symptom control, troubled by tolerability or adverse events, or experiencing progression? This study didn't address that, but the researchers say the reasons ought to be determined.  

The current data came from the Truven Health Analytics MarketScan Research Databases of roughly 25 million Americans enrolled in commercial or employer-sponsored health insurance plans.