Background Current treatments for psoriatic arthritis (PsA) are associated with a range of limitations, e.g. side effects, safety concerns and inadequate efficacy. The economic burden of biologic (b)DMARD failure among patients (pts) with PsA is thought to be substantial,1 but there is a need to quantify this formally.
Objectives To evaluate PsA treatment failure (i.e. discontinuation and switching rates) in a US managed care setting and its economic consequences.
Methods Pts aged ≥18 years with 2 diagnosis codes for PsA and 1 claim for a bDMARD from 1 Jan 2007 to 31 Mar 2015 in the Truven Health MarketScan® Database (Commercial and Supplemental Medicare) were eligible for the study. Pts were considered incident if they did not have a PsA diagnosis or a bDMARD prescription during 1 year prior to first PsA diagnosis in the study period, and as prevalent otherwise. Pts had a 1-year follow-up from first PsA diagnosis in the study period. The percentages of pts discontinuing a drug, switching to another drug or continuing on the same drug for 1 year from first date of treatment were reported. Healthcare costs for 1 year from initiation of the first bDMARD, (medical and drug costs associated with treatment failures) were reported as cost per-pt-per-month (PPPM), and a generalized linear model was used to analyse the cost after controlling for various demographic variables.
Results Of the 18,632 pts treated with a bDMARD, 1298 (6.97%) were incident and 17,334 (93.03%) prevalent. Almost half (n=8994; 48.27%) of the pts continued on the index bDMARD for 1 year. Treatment failed for the remaining pts, with 7852 (42.14%) discontinuing, and 1630 (8.75%; overlap ≤30 days between drugs) and 156 (0.84%; overlap >30 days) switching. In the prevalent group, 8754 (50.50%) pts continued on the index drug, 7043 (40.63%) discontinued, and 1399 (8.07%; overlap ≤30 days) and 138 (0.79%; overlap >30 days) switched to another drug. Among incident pts, only 240 (18.49%) continued, 809 (62.33%) discontinued, and 231 (17.80%; overlap ≤30 days) and 18 (1.38%; overlap >30 days) switched to another drug. Pts with an overlap >30 days were excluded from the analysis. Overall, pts who switched had a higher PPPM total cost ($3317) than those who discontinued ($2650; p<0.0001) or continued ($2708; p<0.0001). Similar results were observed in the prevalent and incident groups, respectively, with pts who switched incurring a higher PPPM total cost ($3241 and $3779) compared with those who discontinued ($2583 and $3237; both p<0.0001) or continued ($2700 and $3080; both p<0.0001). Increasing age (per year) was associated with a 0.57% higher total cost in the incident group (p=0.002) and with a 0.49% higher cost in the prevalent group (p<0.0001). Among prevalent pts, females had a 3.08% higher cost than males (p=0.0069). The Charlson Co-morbidity Index score predicted a higher cost (p<0.0001) among prevalent but not incident pts.
Conclusions In a US claims study population of pts with PsA, rates of treatment failure as defined by switching or discontinuation were high. Follow-up costs for pts who switched were higher than for pts who continued or discontinued their medication. Baseline age, female sex and co-morbidities were associated with higher treatment costs.
Taylor PC, et al. Rheumatol Int 2016;36:685–95.
Disclosure of Interest K. Price Employee of: Bristol-Myers Squibb, E. Alemao Shareholder of: Bristol-Myers Squibb, Employee of: Bristol-Myers Squibb, L. Burns Shareholder of: Bristol-Myers Squibb, Employee of: Bristol-Myers Squibb, Z. Guo Shareholder of: Bristol-Myers Squibb, Employee of: Bristol-Myers Squibb, V. Anupindi: None declared, S. Goday: None declared