Low Adherence to Biologic Therapy Seen in Medicare Patients with Psoriasis

Patients with moderate-to-severe plaque psoriasis covered by Medicare are less likely to adhere to their medication regimen.

A new study has found that about half of Medicare patients who start a biological therapy for moderate-to-severe plaque psoriasis cease treatment within 1 year.

"Such suboptimal patterns of biologic use warrant further investigation, however our findings do suggest that high out-of-pocket costs under Medicare Part D are a potential factor," said study author Jalpa A. Doshi, PhD.

In the study, published by Journal of the American Academy of Dermatology, researchers gathered national Medicare claims data for patients with plaque psoriasis,focusing on 2707 patients with moderate-to-severe plaque psoriasis who started treatment during 2010 to 2011 with the biologic drugs infliximab (Remicade), etanercept (Enbrel), adalimumab (Humira), or ustekinumab (Stelara).

Researchers found that on average, patient use of biologics during the following year was about 61% of the days in that year. Patients who used the drugs for at least 80% of the days were said to be adherent to their medication, but only 38% of patients met that criteria.

Approximately 46% of patients discontinued their medication. Only 8% switched to another drug and 9% restarted the therapy after a gap of 90 or more days.

"Given that prior research has shown interruptions in biologic treatment for psoriasis to be associated with poorer outcomes compared to continuous therapy, understanding the reasons for treatment non-adherence is critical," said senior author Joel M. Gelfand, MD, MSCE.

According to the article, higher out-of-pocket costs is a possible factor that affected adherence. Patients who were ineligible for Medicare Part D and responsible for high cost sharing were more likely to be non-adherent and discontinue the medication.

Researchers found that female patients were also more likely to be non-adherent.

"In addition, the analysis found differences in adherence depending on which biologic agent the patients were taking. Regardless, low adherence and high discontinuation rates were observed for all 4 of the biologics," Dr. Doshi concluded.