Drug survival of biologics in psoriasis: An Australian multicentre retrospective study

Drug survival, which refers to the time from treatment initiation to discontinuation, provides a surrogate measure of the effectiveness of a biologic in a real-world setting (J Invest Dermatol, 2015, 135, 1). The aim of this study was to determine the drug survival of biologics that are currently available in Australia. We also analysed the treatment efficacy of these biologics and reasons for discontinuation.

Retrospective data from outpatient Dermatology biologic clinics in Westmead Hospital and Royal Prince Alfred Hospital (Sydney, Australia) from April 2006 to December 2020 were collected. Kaplan-Meier analysis was used to calculate drug survival.

A total of 306 patients who underwent 566 treatment courses were analysed. Guselkumab was observed to have the longest drug survival, with cumulative drug survival rates of 94.2% ± 4.0 at 1- and 5-years. This was followed by ixekizumab which had a 1-year survival rate of 87.2% ± 4.5 and 5-year survival rate of 59.4% ± 9.5. Ixekizumab and guselkumab were also noted to have superior treatment efficacy compared with other biologics, with PASI-75 rates of 94.9% and 93.8%, respectively. The most common reasons for treatment discontinuation were a lack of initial efficacy to treatment and a loss of efficacy over time despite an initial response, respectively.

To our knowledge, this is the first Australian study to report on outcomes of multiple new biologics that are currently in use for the treatment of chronic plaque psoriasis. Overall, this study provides insight into patterns of care from a local experience that may help guide the management of moderate-to-severe psoriasis.