A real-world comparison of drug discontinuation rates between clinical trial eligible and ineligible patients in the British Association of Dermatologists Biologic Interventions Register (BADBIR).

Background: There is preliminary evidence that psoriasis patients eligible for clinical trials of biologics are not representative of real-world patients.
Aim: The aim of the study was to determine whether patients enrolled in BADBIR identified as Eligible or Ineligible for clinical trials differed in drug discontinuation.
Methods: BADBIR is a pharmacovigilance register of psoriasis patients exploring the long-term safety of biologics compared to conventional systemic therapies. Patients with at least 6 months of follow-up who registered on etanercept (Enbrel only; n=1509), adalimumab (n=4000) or ustekinumab (n=1627) were included in the analysis. Eligibility criteria were extracted from phase III trials submitted for licensing. Four eligibility categories were identified: Eligible; Ineligible; insufficient baseline Psoriasis Area and Severity Index (PASI) only; missing baseline PASI only. The cumulative incidence of drug discontinuation at 12 months by stop reason (adverse events; ineffectiveness; other) for Eligible and Ineligible patients per drug was calculated.
Results: 838 (56%) etanercept, 2219 (56%) adalimumab and 754 (46%) ustekinumab registrations were classified as Eligible with 367 (24%), 282 (7%) and 394 (24%) registrations classified as Ineligible, respectively. The proportion of Eligible vs Ineligible patients discontinuing therapy for each stop reason were similar: etanercept adverse events 3% vs 4%, ineffectiveness 11% vs 15% and other 4% vs 2%; adalimumab adverse events 3% vs 5%, ineffectiveness 8% vs 6% and other 2% vs 5%; ustekinumab adverse events 3% vs 2%, ineffectiveness 3% vs 5% and other 2% vs 2%.
Conclusion: Ineligible patients did not discontinue therapy at a higher rate than Eligible patients in the first 12 months of treatment in BADBIR.