The IL-23 inhibitor guselkumab has the longest drug survival of any biologic currently available in Australia for psoriasis, followed by the anti-IL-17A antibody ixekizumab, local data show.
The figures follow the first local study to report on outcomes of multiple new biologics currently in use for the treatment of chronic plaque psoriasis, which also revealed wide variance in effectiveness between products.
Drug survival, which refers to the time from treatment initiation to discontinuation, varied significantly between biologics examined, with the anti-TNFs etanercept, adalimumab and the anti-IL-17A secukinumab each having continuation rates below 35% at five years.
By contrast, above 94% of patients prescribed guselkumab were still taking the drug at five years, giving it far and away the best survival over that duration, the researchers said.
“The most common reasons for discontinuation of biologics were a lack of initial efficacy, followed by a loss of efficacy over time,” they reported in Australasian Journal of Dermatology (link here).
The study used retrospective data from outpatient dermatology clinics at two major Sydney hospitals from April 2006 to December 2020 and included a total of 306 patients who underwent a combined 566 treatment courses.
| Cumulative drug survival rates at Years 1, 2, 3 and 5 | ||||
| 1-Year survival % (SE) | 2-Year survival % (SE) | 3-Year survival % (SE) | 5-Year survival % (SE) |
|
| Adalimumab | 70.1 (4.7) | 55.8 (5.3) | 50.6 (5.4) | 32.2 (5.3) |
| Infliximab | 82.6 (4.6) | 69.1 (5.6) | 60.0 (6.0) | 50.4 (6.2) |
| Etanercept | 57.7 (9.7) | 46.2 (9.8) | 34.6 (9.3) | 30.3 (9.1) |
| Ustekinumab | 81.2 (3.3) | 70.7 (4.1) | 61.7 (4.5) | 46.7 (5.0) |
| Secukinumab | 85.7 (3.5) | 70.5 (4.8) | 51.1 (5.5) | 33.1 (6.6) |
| Ixekizumab | 87.2 (4.5) | 74.2 (6.2) | 66.0 (7.9) | 59.4 (9.5) |
| Guselkumab | 94.2 (4.0) | 94.2 (4.0) | 94.2 (4.0) | 94.2 (4.0) |
| Risankizumab | NR | NR | NR | NR |
NR: Not reached
Interestingly, the two biologics with the longest drug survival, 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.
While Australia-specific, the findings were broadly similar to those from international research, with the notable exception of ixekizumab, which seemed to perform better in the present study than elsewhere, according to the researchers.
Possible reasons for the difference were larger population of biologic-naïve patients in the Australian data, but also differing patterns of prescribing compared with other countries, they said.
“Due to the availability of several new biologic therapies and the resultant possibility of complete skin clearance, clinicians may have a lower threshold for switching therapy,” the authors wrote.
“However, given the relatively high rates of skin clearance among patients on ixekizumab in this study, it is more likely that the discrepancy is due to a relatively high proportion of biologic-naïve patients on ixekizumab.”