In a previous phase 3 trial, patients with the main psoriasis risk allele HLA-C*06:02 have shown a better response to ustekinumab. The present study, presented by Dr Oras Alabas (University of Manchester, UK), aimed to investigate whether HLA-C*06:02 affects the discontinuation of biologics in a large cohort of psoriasis patients in the real world. BADBIR is a UK pharmacovigilance register designed to assess the long-term safety of newer drugs by following a real-world population of psoriasis patients of different sex, age, ethnicity, BMI, and comorbidities.
The population consisted of patients with chronic plaque psoriasis registering to BADBIR from 2007–2020. All patients were treated with adalimumab, etanercept, secukinumab, or ustekinumab, with at least 6 months follow-up. Moreover, HLA-C*06:02 data was available for all patients. Exposure time was calculated from initiation to the discontinuation of therapy and/or was censored at the latest follow-up. Included in the analysis were 3,199 patients, of whom 52% were HLA positive.
Compared with HLA negative psoriasis patients, they had an earlier onset of disease and were less likely to have psoriatic arthritis. “The HLA positive patients showed a better overall drug survival on ustekinumab compared to HLA negative patients. The same pattern was seen in adalimumab treated patients with non-imputed data,” Dr Oras Alabas (University of Manchester, UK) explained. However, only the association with ustekinumab remained significant when using imputed data.
Further, HLA-positive patients had a 38% lower relative risk to stop treatment owing to lack of effectiveness than HLA -negative patients. HLA status did not influence drug survival of patients discontinuing due to adverse events. Thus, Dr Alabas concluded that HLA status is a predictive biomarker of drug survival for ustekinumab and may be for adalimumab but not for etanercept or secukinumab in the management of psoriasis.