Brodalumab for the Treatment of Moderate-to-Severe Plaque Psoriasis: An Evidence Review Group Evaluation of a NICE Single Technology Appraisal

Ros Wade, Alessandro Grosso, Emily South, Claire Rothery, Pedro Saramago, Laetitia Schmitt, Kath Wright, Stephen Palmer

As part of the National Institute for Health and Care Excellence single technology appraisal process, brodalumab was assessed to determine the clinical and cost effectiveness of its use in the treatment of moderate-to-severe plaque psoriasis. The Centre for Reviews and Dissemination and the Centre for Health Economics Technology Assessment Group at the University of York were commissioned to act as the independent Evidence Review Group. This article provides a summary of the Evidence Review Group's review of the company's submission, the Evidence Review Group report and the National Institute for Health and Care Excellence Appraisal Committee's subsequent guidance issued in March 2018. The main clinical effectiveness data were derived from three well-conducted, multicentre, double-blind randomised controlled trials. The trials demonstrated that brodalumab statistically significantly reduced the severity of psoriasis and its impact on health-related quality of life, compared with placebo, at 12 weeks. In comparison with ustekinumab, statistically significantly more patients taking brodalumab had reduced psoriasis severity at 12 weeks. Psoriasis severity and quality of life also appeared improved at 52 weeks, although statistical significance was not assessed. Withdrawal rates were comparable to drug survival rates of other biological therapies and rates of adverse events were similar between brodalumab and ustekinumab. A network meta-analysis was presented, comparing brodalumab with other therapies available at the same point in the treatment pathway (i.e. in patients for whom standard systemic therapy or phototherapy is inadequately effective, not tolerated or contraindicated). The network meta-analysis ranked treatments in order of effectiveness, in terms of achieving different levels of Psoriasis Area and Severity Index response. The results indicated that brodalumab had a similar probability of response to ixekizumab, secukinumab and infliximab and a higher probability of response than ustekinumab, adalimumab, etanercept, apremilast, dimethyl fumarate and placebo. The company's economic model compared nine treatment sequences that included three lines of active therapy, consisting of brodalumab and other comparators recommended by the National Institute for Health and Care Excellence, followed by best supportive care. The sequence with brodalumab in the first-line position dominated sequences that started with adalimumab, infliximab, secukinumab and ustekinumab. The incremental cost-effectiveness ratio of the brodalumab sequence compared to less effective and non-dominated sequences ranged from £7145 (vs. the etanercept sequence) to £13,353 (vs. the dimethyl fumarate sequence) per quality-adjusted life-year gained. The incremental cost-effectiveness ratio for the more costly and effective ixekizumab sequence was £894,010 per quality-adjusted life-year gained compared to the brodalumab sequence. At a threshold of £20,000 per quality-adjusted life-year gained, the brodalumab sequence had the highest probability of being cost effective (96%). The main limitation of the company's economic model was the restrictive nature of the sequences compared. Twelve separate scenarios based on key uncertainties were explored by the Evidence Review Group. The only scenarios where brodalumab was ranked lower than first were not considered to be more appropriate or plausible than the assumptions or scenarios included in the company's base case. The treatment rankings identified in the Evidence Review Group's alternative base case were identical to those derived from the company's base case model. At the first National Institute for Health and Care Excellence Appraisal Committee meeting, the Committee concluded that brodalumab appears to be as effective as other anti-interleukin-17 agents and is cost effective, based on the discount agreed in the patient access scheme. Brodalumab is recommended as an option for treating adults with severe plaque psoriasis (defined by a total Psoriasis Area and Severity Index score of 10 or more and a Dermatology Life Quality Index score of more than 10) who have not responded to other systemic non-biological therapies. Brodalumab should be stopped at 12 weeks if the psoriasis has not responded adequately.