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INTRODUCTION: Health technology assessment (HTA) agencies express a clear preference for randomized controlled trials when assessing the comparative efficacy of two or more treatments. However, an indirect treatment comparison (ITC) is often necessary where a direct comparison is unavailable or, in some cases, not possible. Numerous ITC techniques are described in the literature. A systematic literature review (SLR) was conducted to identify all the relevant literature on existing ITC techniques, provide a comprehensive description of each technique and evaluate their strengths and limitations from an HTA perspective in order to develop guidance on the most appropriate method to use in different scenarios. METHODS: Electronic database searches of Embase and PubMed, as well as grey literature searches, were conducted on 15 November 2021. Eligible articles were peer-reviewed papers that specifically described the methods used for different ITC techniques and were written in English. The review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. RESULTS: A total of 73 articles were included in the SLR, reporting on seven different ITC techniques. All reported techniques were forms of adjusted ITC. Network meta-analysis (NMA) was the most frequently described technique (in 79.5% of the included articles), followed by matching-adjusted indirect comparison (MAIC) (30.1%), network meta-regression (24.7%), the Bucher method (23.3%), simulated treatment comparison (STC) (21.9%), propensity score matching (4.1%) and inverse probability of treatment weighting (4.1%). The appropriate choice of ITC technique is critical and should be based on the feasibility of a connected network, the evidence of heterogeneity between and within studies, the overall number of relevant studies and the availability of individual patient-level data (IPD). MAIC and STC were found to be common techniques in the case of single-arm studies, which are increasingly being conducted in oncology and rare diseases, whilst the Bucher method and NMA provide suitable options where no IPD is available. CONCLUSION: ITCs can provide alternative evidence where direct comparative evidence may be missing. ITCs are currently considered by HTA agencies on a case-by-case basis; however, their acceptability remains low. Clearer international consensus and guidance on the methods to use for different ITC techniques is needed to improve the quality of ITCs submitted to HTA agencies. ITC techniques continue to evolve quickly, and more efficient techniques may become available in the future.
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INTRODUCTION: A systematic literature review (SLR) and network meta-analysis (NMA) were conducted to evaluate the comparative efficacy of brolucizumab relative to other anti-vascular endothelial growth factor (VEGF) treatments for neovascular age-related macular degeneration (nAMD) at 1 and 2 years, and overall safety and injection frequency of each treatment. METHODS: An SLR identifying randomized controlled trials (RCTs) published before June 2021 according to a pre-specified protocol was followed by a Bayesian NMA to compare brolucizumab (6 mg q12w/q8w) against sham and all relevant anti-VEGF regimens. Pooled mean injection frequency, serious adverse ocular events, and discontinuation rates were estimated for each treatment regimen. RESULTS: Nineteen RCTs were included in NMA base-case analysis. Brolucizumab (6 mg q12w/q8w) with loading-phase (LP) demonstrated superior best-corrected visual acuity (BCVA) gains to sham both at year 1 (mean difference 16.8 [95%CrI 13.3, 20.4]) and year 2 (mean difference 21.2 [95%CrI 17.4, 25.0]) and was comparable to other anti-VEGFs. Brolucizumab (6 mg q12w/q8w) also showed superior retinal thickness reduction to most comparators including ranibizumab (0.5 mg q4w; year 1 mean difference - 50.1 [95%CrI - 70.3, - 29.8]; year 2 mean difference - 49.5 [95%CrI - 70.8, - 28.6]), aflibercept (2 mg q8w; year 1 mean difference - 39.7 [95%CrI - 52.9, - 26.4]; year 2 mean difference - 35.0 [95%CrI - 49.1, - 21.4]), and faricimab (6 mg q16w/q8w; year 1 mean difference - 27.6 [95%CrI - 42.3, - 12.8]). Brolucizumab (6 mg q12w/q8w) showed similar rates of treatment discontinuation and serious and overall adverse events (both years). At year 2, pooled annualized injection frequency was lowest for brolucizumab (6 mg q12w/q8w) and highest for ranibizumab (0.5 mg q4w) at 5.7 and 11.5 injections annually, respectively. CONCLUSION: Among all licensed anti-VEGF treatments, brolucizumab showed superior reduction in retinal thickness and comparable BCVA gains and discontinuation rates, despite having the lowest injection frequency. The current study provides the most up-to-date, robust comparison of treatments for nAMD.