Medication persistence of targeted immunomodulators for plaque psoriasis: A retrospective analysis using a U.S. claims database

Abstract

Purpose Studies of medication persistence in plaque psoriasis have shown inconsistent results, likely due to differing definitions of nonpersistence and of the permissible gap between refills. Also, medication persistence information for two recently approved drugs, apremilast and ixekizumab, is limited. Methods We use the Truven Health MarketScan claims database to assess persistence for six drugs: adalimumab, apremilast, etanercept, ixekizumab, secukinumab, and ustekinumab. We define the permissible gap in three ways: 150 days for ustekinumab and 90 days for all other drugs (150/90 model); 120 days for all drugs (120 model); and twice the days' supply for all drugs (days' supply model). To estimate unadjusted persistence, we use Kaplan‐Meier curves, and a proportional hazards model to estimate the adjusted risk of non‐persistence. Results Ustekinumab is most sensitive to changes in the definition of permissible gap, likely because of its longer maintenance dosing interval. Among targeted drug‐experienced patients using ustekinumab, median persistence is 358 days (95% confidence interval: 343‐371) in the 150/90 model and 189 days (179‐199) in the days' supply model. Among targeted drug‐experienced patients, median persistence in the days' supply model is longest for ixekizumab and secukinumab at 252 (217‐301) and 222 (210‐244) days, respectively. We also find that adjusted risk of nonpersistence increases by approximately 1% per year at treatment start. Conclusion The definition of permissible gap meaningfully changes both absolute and ordinal estimates of medication persistence. Each definition has unique limitations, which should be considered when interpreting persistence data.

Drug survival of ixekizumab, TNF inhibitors, and other IL‐17 inhibitors in real‐world patients with psoriasis: The Corrona Psoriasis Registry

“…Our 12‐month drug‐survival rates among biologic‐experienced patients of 65% for ixekizumab vs 34% for TNFi, and 54% for non‐ixekizumab IL‐17i initiators, are comparable to those recently reported for adalimumab (12 months survival: 55% for ixekizumab vs 47% for adalimumab) 3 and secukinumab (12 months survival: 57% for ixekizumab vs 50% for secukinumab) 25 . The higher drug survival observed among ixekizumab users is consistent despite most users being biologic‐experienced, a subgroup of patients who have been shown to have lower drug survival than biologic‐naïve users 38, 39 . Notably, drug survival for all three groups was similar for approximately 6 months, at which point the survival curves separated and ixekizumab performed better out to 24 months of follow‐up.…”

“…25 The higher drug survival observed among ixekizumab users is consistent despite most users being biologic-experienced, a subgroup of patients who have been shown to have lower drug survival than biologic-naïve users. 38,39 Notably, drug survival for all three groups was similar for approximately 6 months, at which point the survival curves separated and ixekizumab performed better out to 24 months of follow-up.…”

A Retrospective Cohort Analysis of Treatment Patterns Over 1 Year in Patients with Psoriasis Treated with Ixekizumab or Guselkumab

“…Overall, patients with psoriasis in clinical practice settings who were treated with ixekizumab had significantly greater persistence with therapy vs. guselkumab when assessed using 45-day and 60-day allowable gaps, but no difference in persistence was observed between groups in the analysis when using a more generous 90-day allowable gap. Previous studies on persistence in psoriasis have used a range of allowable gaps from 45 to 150 days [16,23,24], and we have previously reported results for comparisons of ixekizumab and adalimumab or secukinumab based on a 60-day gap [17,18]. However, a recent analysis of multiple drugs for psoriasis found that persistence estimates for ustekinumab, which has a 12-week dosing interval, varied more widely depending on the allowable treatment gap than other drugs with shorter dosing and refill intervals [16].…”

“…Previous studies on persistence in psoriasis have used a range of allowable gaps from 45 to 150 days [16,23,24], and we have previously reported results for comparisons of ixekizumab and adalimumab or secukinumab based on a 60-day gap [17,18]. However, a recent analysis of multiple drugs for psoriasis found that persistence estimates for ustekinumab, which has a 12-week dosing interval, varied more widely depending on the allowable treatment gap than other drugs with shorter dosing and refill intervals [16]. Our results are consistent with this finding in that the significance of differences in persistence between ixekizumab, with typical maintenance dosing every 4 weeks, and guselkumab, with typical maintenance dosing every 8 weeks, varied depending upon the length of the allowable gap.…”

“…Ixekizumab, an interleukin (IL)-17A inhibitor approved for use in adult patients with moderate-to-severe psoriasis, has demonstrated long-term efficacy and safety up to 5 years [14,15], and has generally shown drug persistence equal to or greater than that of other biologics for psoriasis [7,9,[16][17][18]. Guselkumab, an IL-23p19 inhibitor also approved for psoriasis, has demonstrated efficacy and safety through 4 years [19].…”