Clinical consequences of antibody formation, serum concentrations, and HLA-Cw6 status in psoriasis patients on Ustekinumab

Background: Ustekinumab for the treatment of psoriasis is currently administered in a standard dosing regimen. However, some patients tend to benefit from alternative dosing regimens, a step toward personalized medicine. Methods: To investigate the role of ustekinumab serum concentrations, anti-ustekinumab antibodies [AUA] and HLA-Cw6 status as tools for optimizing ustekinumab treatment, a multicenter prospective cohort study was conducted at an academic hospital with affiliated nonacademic hospitals in Belgium (cohort 1) and 2 academic hospitals in the Netherlands (cohort 2 and 3). Patients with plaque-type psoriasis were eligible if treated with ustekinumab for >16 weeks. Serum samples and Psoriasis Area and Severity Index scores were obtained at baseline, week 16, 28, 40, 52, and/or >64 of ustekinumab treatment. Results: A total of 137 patients with 229 observations for serum concentrations and AUA and 61 observations for HLA-Cw6 status were included. Presence of AUA (prevalence of 8.7%) was significantly associated with a diminished clinical response (P = 0.032). The median ustekinumab trough concentration was 0.3 mcg/mL (<0.02-3.80). No differences in serum concentrations were observed between moderate to good responders and nonresponders (P = 0.948). Serum trough concentrations were not affected by methotrexate comedication. Prevalence of HLA-Cw6 positivity was 41% with no statistically significant difference in clinical response between HLA-Cw6-positive and HLA-Cw6-negative patients (P = 0.164). Conclusions: The presence of AUA was associated with treatment failure in this patient population; measurement of AUA may therefore be a candidate marker for personalized pharmacotherapy. The clinical utility of ustekinumab serum trough concentrations or HLA-Cw6 status determination remains less clear. Further exploration on the potential of measuring ustekinumab serum concentrations and other biomarkers in predicting therapy outcomes should be encouraged

Combined use of systemic agents for psoriasis: a systematic review

Combined use of systemic agents may be necessary to achieve disease control in therapy-resistant patients. However, to our knowledge, an overview of evidence, including quality assessments, is not yet available, and no guidance on monitoring, contraindications, and interactions exists. To summarize and critically appraise the evidence on efficacy and safety of combination therapy with systemic agents in plaque-type psoriasis. Through March 2013, an electronic search limited to randomized clinical trials was performed in MEDLINE, EMBASE, The Cochrane Library, and ongoing trial registers. The quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation approach. The initial search retrieved 2583 records, of which 17 met the inclusion criteria. Most studies favored combination therapy, albeit with low significance and low quality of evidence. Etanercept plus methotrexate was the only combination therapy investigated with an adequate sample size (n = 478). In the short term, this combination had superior efficacy with a moderate quality of evidence compared with etanercept monotherapy (Psoriasis Area and Severity Index, 75; relative risk, 1.28; 95% CI, 1.14-1.45). Although this finding coincided with an increase in adverse events (relative risk, 1.25; 95% CI, 1.10-1.42), the overall safety profile remained acceptable. This systematic review provides a comprehensive overview on the validity of different systemic combination therapies. For most combinations, insufficient evidence is available. Initial results indicate that combined therapy with etanercept plus methotrexate may be beneficial in patients that are therapy resistant under intensive follow-up. Dose reductions should be taken into account to minimize adverse effect