Ustekinumab for the treatment of moderate to severe psoriasis

This paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of ustekinumab for the treatment of moderate to severe psoriasis based upon a review of the manufacturer's submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The submission's main evidence came from three randomised controlled trials (RCTs), of reasonable methodological quality and measuring a range of clinically relevant outcomes. Higher proportions of participants treated with ustekinumab (45 mg and 90 mg) than with placebo or etanercept achieved an improvement on the Psoriasis Area and Severity Index (PASI) of at least 75% (PASI 75) after 12 weeks. There were also statistically significant differences in favour of ustekinumab over placebo for PASI 50 and PASI 90 results, and for ustekinumab over etanercept for PASI 90 results. A weight-based subgroup dosing analysis for each trial was presented, but the methodology was poorly described and no statistical analysis to support the chosen weight threshold was presented. The manufacturer carried out a mixed treatment comparison (MTC); however, the appropriateness of some of the methodological aspects of the MTC is uncertain. The incidence of adverse events was similar between groups at 12 weeks and withdrawals due to adverse events were low and less frequent in the ustekinumab than in the placebo or etanercept groups; however, statistical comparisons were not reported. The manufacturer's economic model of treatments for psoriasis compared ustekinumab with other biological therapies. The model used a reasonable approach; however, it is not clear whether the clinical effectiveness estimates from the subgroup analysis, used in the base-case analysis, were methodologically appropriate. The base-case incremental cost-effectiveness ratio for ustekinumab versus supportive care was 29,587 pounds per quality-adjusted life-year (QALY). In one-way sensitivity analysis the model was most sensitive to the number of hospital days associated with supportive care, the cost estimate for intermittent etanercept 25 mg and the utility scores used. In the ERG's scenario analysis the model was most sensitive to the price of ustekinumab 90 mg, the proportion of patients with baseline weight > 100 kg and the relative risk of intermittent versus continuous etanercept 25 mg. In the ERG's probabilistic sensitivity analysis ustekinumab had the highest probability of being cost-effective at conventional NICE thresholds, assuming the same price for the 45-mg and 90-mg doses; however, doubling the price of ustekinumab 90 mg resulted in ustekinumab no longer dominating the comparators. In conclusion, the clinical effectiveness and cost-effectiveness of ustekinumab in relation to other drugs in this class is uncertain. Provisional NICE guidance issued as a result of the STA states that ustekinumab is recommended as a treatment option for adults with plaque psoriasis when a number of criteria are met. Final guidance is anticipated in September 2009.

Developments in psoriasis and psoriatic arthritis

Psoriasis and psoriatic arthritis are common conditions for which treatment options have until recently been extremely limited. Recent advances in our understanding of the immunology and genetics underlying these conditions have been rapid, and have contributed to the development of new therapies for these diseases. This article discusses the current state of the art in our understanding of the aetiopathogenesis of psoriasis and psoriatic arthritis, and current therapies for the diseases.

Anti-TNF antibody-induced psoriasiform skin lesions in patients with inflammatory bowel disease are characterised by interferon-γ-expressing Th1 cells and IL-17A/IL-22-expressing Th17 cells and respond to anti-IL-12/IL-23 antibody treatment

Background We analysed incidence, predictors, histological features and specific treatment options of anti-tumour necrosis factor alpha (TNF-alpha) antibody-induced psoriasiform skin lesions in patients with inflammatory bowel diseases (IBD).

Design Patients with IBD were prospectively screened for anti-TNF-induced psoriasiform skin lesions. Patients were genotyped for IL23R and IL12B variants. Skin lesions were examined for infiltrating Th1 and Th17 cells. Patients with severe lesions were treated with the anti-interleukin (IL)-12/IL-23 p40 antibody ustekinumab.

Results Among 434 anti-TNF-treated patients with IBD, 21 (4.8%) developed psoriasiform skin lesions. Multiple logistic regression revealed smoking (p=0.007; OR 4.24, 95% CI 1.55 to 13.60) and an increased body mass index (p=0.029; OR 1.12, 95% CI 1.01 to 1.24) as main predictors for these lesions. Nine patients with Crohn's disease and with severe psoriasiform lesions and/or anti-TNF antibody-induced alopecia were successfully treated with the anti-p40-IL-12/IL-23 antibody ustekinumab (response rate 100%). Skin lesions were histologically characterised by infiltrates of IL-17A/IL-22-secreting T helper 17 (Th17) cells and interferon (IFN)-gamma-secreting Th1 cells and IFN-alpha-expressing cells. IL-17A expression was significantly stronger in patients requiring ustekinumab than in patients responding to topical therapy (p=0.001). IL23R genotyping suggests disease-modifying effects of rs11209026 (p.Arg381Gln) and rs7530511 (p.Leu310Pro) in patients requiring ustekinumab.

Conclusions New onset psoriasiform skin lesions develop in nearly 5% of anti-TNF-treated patients with IBD. We identified smoking as a main risk factor for developing these lesions. Anti-TNF-induced psoriasiform skin lesions are characterised by Th17 and Th1 cell infiltrates. The number of IL-17A-expressing T cells correlates with the severity of skin lesions. Anti-IL-12/IL23 antibody therapy is a highly effective therapy for these lesions.

Increased expression of heat shock protein 90 in keratinocytes and mast cells in patients with psoriasis.

BACKGROUND Psoriasis is a chronic inflammatory skin disease and various stress factors mediate inflammation. Heat shock protein (HSP) 90 plays an important role in cell survival; cytokine signaling, such as interleukin-17 receptor signaling; and immune responses. OBJECTIVE We sought to elucidate protein expression and distribution of HSP90 in psoriasis. METHODS HSP90 expression and its cellular source were analyzed on normal-appearing, nonlesional, lesional, and ustekinumab-treated psoriatic skin using immunohistochemistry and double immunofluorescence. RESULTS HSP90α, the inducible isoform of HSP90, was significantly up-regulated in epidermal keratinocytes and mast cells of lesional skin and down-regulated after ustekinumab therapy. LIMITATIONS There was a limited sample size. CONCLUSIONS HSP90 from keratinocytes and mast cells is a key regulator of psoriatic inflammation and HSP90 inhibitors may represent a novel therapeutic approach to the disease.