When using biologic therapies for psoriasis, it is important to evaluate long-term efficacy (>4 years of follow-up). Biologic drug survival in psoriasis reflects long-term performance in real-life settings. Prior studies have yielded inconsistent results.
Vilarrasa et al (J Am Acad Dermatol. 2016;74:1066-1072) conducted an observational retrospective study called ORBIT (Outcome and Retention Rate of Biologic Treatments for Psoriasis) to determine drug survival (the mean length of time patients remain on a drug) in a cohort of 427 patients (63.5% male; mean age, 50.2 years) with moderate to severe psoriasis vulgaris (mean baseline psoriasis area and severity index [PASI], 16.4). In addition to determining mean drug survival times for etanercept, infliximab, adalimumab, and ustekinumab, investigators searched for variables that positively or negatively affected drug survival times. Data were extracted from clinical records of patients treated with biologic agents over a 4-year period. Drug survival was analyzed using the Kaplan-Meier method and the influence of several covariates was assessed using Cox regression.
The investigators evaluated 703 treatment courses. The overall median drug survival was 31.0 months. Cumulative probability of drug survival was lower in obese patients (23.0 months; 95% CI, 17.4-28.6) than in patients with body mass index less than 30 (37.3 months; 95% CI, 29.4-45.1; P=.001). Drug survival was significantly higher for ustekinumab than for any other biologic agent (log-rank test, P<.001). Multivariate analysis showed that obesity, etanercept treatment, and strict adherence to approved doses were associated with an increased probability of drug withdrawal, whereas ustekinumab treatment and PASI 75 and PASI 90 responses at week 16 prolonged drug survival. Data were collected retrospectively.
What’s the issue?
These results should help to educate patients and to manage expectations about drug efficacy. They should also give guidance to physicians. Patients who respond rapidly to biologics—PASI 70 or PASI 90 clearance during the induction phase—are more likely to enjoy long-term remission. In contrast, those with a high body mass index should be advised that their psoriasis may take longer to respond to treatment and may need combination therapy for optimal clearance.