Brodalumab significantly improved plaque psoriasis in this 12-week, phase 2 study. (Funded by Amgen; ClinicalTrials.gov number, NCT00975637.).

SummaryBackground The interleukin-17 cytokine family plays a central role in psoriasis pathogenesis. Objectives To evaluate the efficacy and safety of brodalumab, a human anti-interleukin-17 receptor antibody, in treating patients with moderate-to-severe plaque psoriasis. Methods In this phase III, double-blind, placebo-controlled study (NCT01708590; AMAGINE-1), adult patients in the U.S.A., Canada and Europe were randomized to brodalumab (140 or 210 mg) or placebo every 2 weeks (Q2W), with an additional dose at week 1, for a 12-week induction phase. At week 12, patients receiving brodalumab who achieved static Physician's Global Assessment 0 or 1 (sPGA success) were rerandomized to the placebo or induction dose. After week 16, patients with sPGA ≥ 3 were re-treated with the induction dose. After ≥ 12 weeks of retreatment, patients with sPGA 2 for ≥ 4 weeks or sPGA ≥ 3 were rescued with brodalumab 210 mg Q2W. At week 12, patients randomized to brodalumab with sPGA ≥ 2 or placebo received brodalumab 210 mg Q2W. Coprimary end points were the percentage of patients with ≥ 75% improvement in Psoriasis Area and Severity Index score (PASI 75) and sPGA success at week 12. Results There were 661 patients randomized: 220 placebo, 219 brodalumab 140 mg and 222 brodalumab 210 mg. At week 12, 60% (140 mg) and 83% (210 mg) vs. 3% (placebo) achieved PASI 75, and 54% (140 mg) and 76% (210 mg) vs. 1% (placebo) achieved sPGA success. The safety profile was considered acceptable. Conclusions Brodalumab therapy resulted in significant clinical benefit and an acceptable safety profile in patients with moderate-to-severe plaque psoriasis.

Although the histologic changes seen in psoriasis have long been well characterized, the underlying cellular and molecular mechanisms have only begun to be elucidated over the past 20 years. Proinflammatory factors such as tumor necrosis factor (TNF)-α have a central role in psoriasis pathogenesis, and many T helper 1 (Th1) cytokines and messenger RNAs are elevated in psoriatic lesions. Interleukin-17A (IL-17A), IL-17F, and other Th17 cell–derived cytokines have been shown in murine models to induce features that mimic human psoriasis. This review focuses on the emerging biology of the IL-17 cytokine family in psoriasis, and on the molecular and genetic information gained from animal models and human clinical studies that confirm IL-17 as a crucial proinflammatory cytokine in psoriasis. Expression of IL-17A, IL-17C, and IL-17F is strikingly increased in psoriatic lesions, and successful therapy is associated with restoration of the expression of a wide range of genes (including effector molecules downstream of IL-17 such as cytokines, chemokines, and antimicrobial peptides) to near normal levels. Therapeutic agents in development that target IL-17 are discussed, and an emerging model of the key role of IL-17 in the pathogenesis of psoriasis is presented.

Objective To examine the efficacy of methotrexate monotherapy relative to etanercept monotherapy and the value of combining methotrexate and etanercept for the treatment of patients with psoriatic arthritis (PsA). Methods In this double‐blind study, 851 patients with PsA were randomized to 1 of 3 treatment arms, as follows: oral methotrexate (20 mg) plus subcutaneous placebo given weekly (n = 284), subcutaneous etanercept (50 mg) plus oral placebo given weekly (n = 284), or subcutaneous etanercept (50 mg) plus oral methotrexate (20 mg) given weekly (combination therapy; n = 283). The American College of Rheumatology 20% improvement (ACR20) response and Minimal Disease Activity (MDA) response at week 24 were the primary end point and key secondary end point, respectively. Other measures of inflammatory arthritis, radiographic progression, and nonarticular disease manifestations were also assessed. Results Patients with PsA had a mean ± SD age of 48.4 ± 13.1 years, and the mean ± SD duration of PsA was 3.2 ± 6.3 years (median 0.6 years). ACR20 and MDA response rates at week 24 were significantly greater in patients who received etanercept monotherapy compared with those who received methotrexate monotherapy (ACR20, 60.9% versus 50.7% of patients [P = 0.029]; MDA, 35.9% versus 22.9% of patients [P = 0.005]), and both were significantly greater in the combination therapy group compared with the methotrexate monotherapy group at week 24 (ACR20, 65.0% versus 50.7% of patients [P = 0.005]; MDA, 35.7% versus 22.9% of patients [P = 0.005]). Other secondary outcomes (ACR50 and ACR70 response rates, proportions of patients achieving a Very Low Disease Activity score, and PsA disease activity scores) showed between‐group differences that were consistent with the primary and key secondary end point results. Furthermore, patients in both etanercept treatment arms showed less radiographic progression at week 48 compared with patients who received methotrexate monotherapy. Outcomes were similar in the combination therapy and etanercept monotherapy groups, except for some skin end points. No new safety signals were seen. Conclusion Etanercept monotherapy and combination therapy with etanercept and methotrexate showed greater efficacy than methotrexate monotherapy in patients with PsA, according to the ACR and MDA response rates and extent of radiographic progression at follow‐up. Overall, combining methotrexate and etanercept did not improve the efficacy of etanercept.

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