About one in ten patients with chronic plaque psoriasis can expect to have sustained long term disease control with biologic drugs, experience from a UK dermatology centre suggests.
After eight years of follow up, 12% (68) of 560 patients treated with biologics (17 infliximab, 38 etanercept, 239 adalimumab, 266 ustekinumab) showed enduring improvements in PASI (Psoriasis Area Severity Index) scores, according to a report from a tertiary centre in Manchester.
The patients who showed long term disease control also showed sustained improvements in the Dermatology Life Quality Index (DLQI), said clinicians from the Dermatology Centre, Salford Royal NHS Foundation Trust and the University of Manchester.
Reporting their findings in the British Journal of Dermatology, they noted that previous studies had shown that psoriasis responses with biologic therapies decreased over time from 77% in the first year to 53% in the third year, but there had been few long term follow up studies.
In the long term follow-up cohort, all the patients were on the same biologic for 8 years or longer. In the patients who showed long term sustained disease control the average duration of therapy ranged from 8.1 years with ustekinumab to 9.9 years with infliximab.
Baseline PASI scores had been in the range of 19.4-20.7, but were maintained at between 1.7 (ustekinumab) to 3.1 (etanercept) after eight years on biologic monotherapy in the responders. DLQI scores were 17.0 to 21.7 at baseline and 1.4-4.2 after eight years.
Most patients had psoriasis onset in their twenties, most were obese and there was a higher proportion of men (n = 47, 69%) with a sustained response compared with women (n = 21, 31%).
There were no serious side-effects reported with etanercept, ustekinumab or adalimumab, while patients treated with infliximab had recurrent chest and skin infections as the most common adverse events reported.
The study authors said the mechanism of drug failure with biologics in psoriasis was not fully understood but was believed to involve immunogenicity as well as being affected by drug levels, obesity and compliance.
“There are still unanswered questions as to why biologics fail to sustain an adequate clinical response in all patients. Our data show that in a small proportion of patients (12%) a long-term satisfactory clinical response is possible,” they wrote.
“Further studies … are needed to understand better the determinants of drug failure and persistent response, but these long-term responders evince clues that may allow identification of key reasons for such success. This may ultimately lead to a personalised approach in developing and choosing the ideal biologic for any patient first time.”