Introduction: This study sought to estimate the global prevalence of transthyretin familial amyloid polyneuropathy (ATTR‐FAP). Methods: Prevalence estimates and information supporting prevalence calculations was extracted from records yielded by reference‐database searches (2005–2016), conference proceedings, and nonpeer reviewed sources. Prevalence was calculated as prevalence rate multiplied by general population size, then extrapolated to countries without prevalence estimates but with reported cases. Results: Searches returned 3,006 records; 1,001 were fully assessed and 10 retained, yielding prevalence for 10 “core” countries, then extrapolated to 32 additional countries. ATTR‐FAP prevalence in core countries, extrapolated countries, and globally was 3,762 (range 3639–3884), 6424 (range, 1,887–34,584), and 10,186 (range, 5,526–38,468) persons, respectively. Discussion: The mid global prevalence estimate (10,186) approximates the maximum commonly accepted estimate (5,000–10,000). The upper limit (38,468) implies potentially higher prevalence. These estimates should be interpreted carefully because contributing evidence was heterogeneous and carried an overall moderate risk of bias. This highlights the requirement for increasing rare‐disease epidemiological assessment and clinician awareness. Muscle Nerve 57: 829–837, 2018

We describe 542 cases of symptomatic hereditary transthyretin amyloid polyneuropathy (ATTR-PN) identified through a review of the literature published between 2005 and 2016. Approximately 18% of the cases were from countries where ATTR-PN is traditionally considered to be endemic (i.e., Portugal, Japan, and Sweden). East Asia (Japan, China, Taiwan, and South Korea) contributed a sizeable combined proportion (37.0%, n = 200) with Japan (n = 92) and China (n = 71) being the primary contributors. The most common genotypes among the 65 genotypes represented in the sample were Val30Met (47.6%), Ser77Tyr (10%), Ala97Ser (6.5%), and Phe64Leu (4.4%). Cases with genotypes other than the aforementioned four had the lowest ages at onset (mean 49.2 [standard deviation {SD} 21.0; inter-quartile range {IQR}14.7]) and diagnosis (mean 53.4 [SD 21.0; IQR 14.7]). Conversely, Phe64Leu mean age of onset was 67.5 (SD 8.8; IQR 5.2) and mean age of diagnosis was 71.3 (SD 8.8; IQR 5.4). The prevalence of upper and lower limb involvement at the time of diagnosis (67 and 41%) observed across all cases is consistent with the typical presentation of ATTR-PN. Other notable findings at the time of diagnosis included a high rate of impotence among the Ala97Ser cases versus all others (67% vs. 21%) and a high rate of non-motor visual symptoms (i.e., visual opacities and glaucoma) in the Ser77Tyr cases versus all others (93% vs. 16%). Though comparisons were made descriptively and were hindered by inconsistency of reporting across the cases, these findings support the notion that ATTR-PN is a more phenotypically and geographically variable disease than is typically considered.

Conventional cost-effectiveness analysis—i.e., assessing pharmaceuticals through a cost per quality-adjusted life year (QALY) framework—originated from a societal commitment to maximize population health given limited resources. This "extra-welfarist" approach has produced pricing and reimbursement systems that are not well- aligned with the unique considerations of orphan drugs. This framework has been slow to evolve along with our increased understanding of the impact of rare diseases, which in turn has complicated the assessment of orphan drugs meant to treat rare diseases. Herein, we (i) discuss the limitations of conventional cost-effectiveness analysis as applied to assessing access to, as well as the pricing and reimbursement of, orphan drugs, (ii) critically appraise alternative and supplemental approaches, and (iii) offer insights on plausible steps forward.

Objective: To assess concomitant extra-articular manifestation (EAM) rates in patients with ankylosing spondylitis (AS) treated with anti-tumor necrosis factor (anti-TNF) agents and examine the economic burden of uveitis and inflammatory bowel disease (IBD) in French and German AS patients. Methods: Previous analyses of uveitis and IBD in AS patients treated with infliximab, etanercept or adalimumab were identified in PubMed/Medline (January 2000 to August 2011). A supplemental analysis incorporated more recent adalimumab clinical trial data (ATLAS [NCT00085644] and RHAPSODY [NCT00478660]). For resource utilization/costs associated with EAMs, the search was expanded to general spondyloarthritis (SpA) conditions (i.e., AS, reactive or psoriatic arthritis, psoriatic spondylitis, IBD and undifferentiated SpA). Direct and indirect yearly costs associated with AS-associated uveitis and IBD were estimated based on interviews with French and German clinicians and literature review. Results: The pooled average rate of anterior uveitis (AU) flares for patients treated with anti-TNF therapy in two meta-analyses and supplemental adalimumab clinical trials was 4.9/100-patient-years (PYs). AU rates (per 100-PYs) were 3.4, 3.7 and 5.7 for infliximab (p = 0.26 vs etanercept; p = 0.86 vs adalimumab), adalimumab (p = 0.033 vs etanercept) and etanercept, respectively. IBD flares (per 100-PYs) were 0.2 for infliximab (p < 0.001 vs etanercept; p = 0.18 vs adalimumab), 0.63 for adalimumab (p = 0.009 vs etanercept) and 2.2 for etanercept. No studies assessing EAM-associated resource utilization or costs in AS patients were found. Direct medical costs associated with IBD treatment ranged from €483 (Germany) to €6443 (France). Clinician-estimated AS-related uveitis direct medical costs were €1410 (Germany) and €1812 (France). Conclusions: Clinical data synthesis demonstrated significantly lower AU flare rates with adalimumab vs etanercept and significantly lower IBD rates with both adalimumab and infliximab vs etanercept. Economic analysis indicated substantial costs associated with AU and IBD flares secondary to AS in France and Germany. Future economic evaluations of anti-TNF agents should incorporate EAMs and subsequent treatment costs. Limitations include restricted availability of randomized, placebo-controlled clinical trial data, inclusion of data from open-label studies, lack of real-world (i.e., non-trial-based) EAM rates and a lack of EAM-specific direct and indirect costs with which to compare the results presented herein.

Denosumab has been approved in the US for skeletal-related event (SRE) prevention in bone-metastatic prostate cancer on the basis of a phase III clinical trial in which denosumab reduced SREs relative to zoledronic acid. Overall survival, disease progression, and serious adverse events did not differ significantly between groups. This analysis assessed the cost-effectiveness of denosumab vs zoledronic acid in bone-metastatic prostate cancer from a US payer perspective. A literature-based Markov model, wherein inputs were selected to reproduce clinical trial outcomes, was developed to estimate the survival, quality-adjusted life-years (QALYs), number and costs of SREs, and drug and administration costs for patients receiving denosumab or zoledronic acid over 27 months. QALYs were estimated by assigning health-state utilities. SRE-related costs and utilities were literature-based. Outcomes were discounted 3% per annum, and model robustness was tested via scenario, univariate, and probabilistic sensitivity analyses. Denosumab resulted in fewer estimated SREs (−0.241; 1.036 vs 1.277), more QALYs (0.0074; 0.9306 vs 0.9232), and lower SRE-related costs (−$2340; $8824 vs $11,164), but higher drug-related costs ($10,181; $23,144 vs $12,963) and total costs ($7841; $31,968 vs $24,127) vs zoledronic acid. The base case estimated cost per QALY-gained was $1,058,741. This analysis was limited by the restricted availability of clinical data and the need to use projection methods beyond the trial time frame. However, a wide range of scenarios predicted denosumab to have an incremental cost/QALY gained above what may be considered acceptable value for money in the US. This raises important questions regarding the pharmacoeconomic value of denosumab in bone-metastatic prostate cancer.