Biologic Switching Increases Health Care Costs Among Patients With Ankylosing Spondylitis and PsA

Switching from one biologic agent to another can have cost implications for payers and patients, but there is limited information on switching rates among patients with ankylosing spondylitis (AS) and psoriatic arthritis (PsA).

In a study of these patient populations, researchers found that biologic switching resulted in higher total health care costs, and this economic burden may be due to medication wastage. The results of the study were presented at the AMCP Annual Meeting during a poster session titled “Healthcare Costs Among Patients with Ankylosing Spondylitis or Psoriatic Arthritis Who Switch or Discontinue Biologics.”

The researchers used the Truven Health MarketScan database to identify adult patients with AS or PsA who had one or more pharmacy claims for a Food and Drug Administration-approved subcutaneous biologic for AS or PsA between January 1, 2016, and December 31, 2016. Eligible patients were required to be continuously enrolled with medical and pharmacy claims one or more years before and after the index date (defined as date of biologic initiation).

The researchers categorized patients as switchers, nonswitchers, and discontinuers based on their biologic utilization pattern during the one-year follow-up period. Among the 788 patients with AS, 15.7% switched, 52.9% did not switch, and 31.3% discontinued. Among the 2,656 patients with PsA, 18.6% switched, 54.7% did not switch, and 26.7% discontinued.

Patients with AS who switched medications had higher mean total health care costs than nonswitchers ($72,562 vs $66,555). This was due to increased medical ($14,423 vs $10,988) and pharmacy costs ($58,139 vs $55,567). Patients with PsA who switched also had higher mean total health care cost than nonswitchers ($80,451 vs $69,985), also due to increased medical ($13,728 vs $13,181) and pharmacy costs ($66,724 vs $56,804).

Patients with both conditions who discontinued treatment had the lowest total health care costs (AS, $39,028; PsA, $52,247) but had the highest medical costs (AS, $16,651; PsA, $23,390).

“While reasons for switching and discontinuation are unknown, these findings may impact formulary decisions due to the potential cost implications of biologic switching and discontinuation in patients with AS or PsA,” the researchers concluded.

The study was sponsored by Novartis Pharmaceuticals.

Yi E, Dai D, Piao O, Zheng J, Hur P, Park Y. Healthcare Costs Among Patients with Ankylosing Spondylitis or Psoriatic Arthritis Who Switch or Discontinue Biologics. Abstract M14. Presented at the AMCP Managed Care & Specialty Pharmacy Annual Meeting, March 25-28; San Diego, CA.