Predictors of Health Utility in Relapsing-Remitting and Secondary-Progressive Multiple Sclerosis: Implications for Future Economic Models of Disease-Modifying Therapies.

BACKGROUND: Decision-analytic models used in economic evaluations of disease-modifying therapies for relapsing-remitting multiple sclerosis (RRMS) have characterized disease progression and accrue quality-adjusted life-years from utility values based on the Expanded Disability Status Scale (EDSS), the occurrence of relapses, and progression to secondary-progressive multiple sclerosis (SPMS). The EDSS, used to characterize disability progression, has several limitations. If the EDSS is the only disability measure used in economic evaluations, the long-term clinical and economic implications of disease-modifying therapies may not be properly assessed. OBJECTIVE: The objective of this study was to explore if supplementary disability measures including the Timed 25-Foot Walk (T25FW), 9-Hole Peg Test (9HPT), and Paced Auditory Serial Addition Test (PASAT) significantly contribute additional information on health utility in RRMS and SPMS otherwise not captured by the EDSS and relapses and, therefore, should be considered in future economic evaluations of disease-modifying therapies. METHODS: Short-Form Six-Dimension utility scores were derived from the RAND 36-Item Health Survey 1.0 individual-level data available in the Multiple Sclerosis Outcome Assessment Consortium (MSOAC) Placebo Database. Repeated-measures mixed-effects models were conducted to estimate the effects of EDSS, T25FW, 9HPT (dominant and non-dominant hand), PASAT, and relapses on changes in utility over time, controlling for demographics. RESULTS: A higher level of EDSS, longer time to complete the T25FW test, and a recent relapse were significant predictors of lower utility in people with RRMS and SPMS. 9HPT and PASAT were not significant predictors. CONCLUSIONS: This study suggests that in addition to EDSS and recent relapses, T25FW significantly predicts utility in RRMS and SPMS. These findings support the use of T25FW to supplement the EDSS and the occurrence of relapses to characterize the course of disease progression and to more accurately accrue quality-adjusted life-years in future economic evaluations of disease-modifying therapies for the treatment of RRMS.

Modeling Approaches in Cost-Effectiveness Analysis of Disease-Modifying Therapies for Relapsing-Remitting Multiple Sclerosis: An Updated Systematic Review and Recommendations for Future Economic Evaluations.

BACKGROUND: Numerous cost-effectiveness analyses (CEAs) of disease-modifying therapies (DMTs) for relapsing-remitting multiple sclerosis (RRMS) have been published in the last three decades. Literature reviews of the modeling methods and results from these CEAs have also been published. The last literature review that focused on modeling methods, without country or time horizon in the inclusion criteria, included studies published up to 2012. Since then, new DMTs have become available, and new models and data sources have been used to assess their cost effectiveness. OBJECTIVE: The aim of this systematic review was to provide a detailed and comprehensive description of the relevant aspects of economic models used in CEAs of DMTs for RRMS, to understand how these models have progressed from recommendations provided in past reviews, what new approaches have been developed, what issues remain, and how they could be addressed. METHODS: EMBASE, MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), the National Health System (NHS) Economic Evaluations Database, the Health Technology Assessment (HTA) Database, and EconLit were searched for cost-effectiveness studies of DMTs for RRMS that used decision-analytic models, published in English between 1 January 2012 and 24 December 2017. The inclusion criteria were as follows: being a full economic evaluation, a decision-analytic model was used, the target population concerned adult patients with RRMS, and being available in full-text format. Studies were not excluded based on the methodological quality. The background information of the included studies, as well as specific information on the components of the economic models related to the areas of recommendation from previous reviews were extracted. RESULTS: Twenty-three studies from ten countries were included. The model structure of these studies has converged over time, characterizing the course of disease progression in terms of changes in disability and the occurrence of relapses over time. Variations were found in model approach; data sources for the natural course of the disease and comparative efficacy between DMTs; number of lines of treatment modeled; long-term efficacy waning and treatment discontinuation assumptions; type of withdrawal; and criteria for selecting adverse events. Main areas for improvement include using long-term time horizons and societal perspective; reporting relevant health outcomes; conducting scenario analyses using different sources of natural history and utility values; and reporting how the model was validated. CONCLUSION: The structure of economic models used in CEAs of DMTs for RRMS has converged over time. However, variation remains in terms of model approach, inputs, and assumptions. Though some recommendations from previous reviews have been incorporated in later models, areas for improvement remain.

Possible role for cellular karyopherins in regulating polyomavirus and papillomavirus capsid assembly.

Polyomavirus and papillomavirus (papovavirus) capsids are composed of 72 capsomeres of their major capsid proteins, VP1 and L1, respectively. After translation in the cytoplasm, L1 and VP1 pentamerize into capsomeres and are then imported into the nucleus using the cellular alpha and beta karyopherins. Virion assembly only occurs in the nucleus, and cellular mechanisms exist to prevent premature capsid assembly in the cytosol. We have identified the karyopherin family of nuclear import factors as possible "chaperones" in preventing the cytoplasmic assembly of papovavirus capsomeres. Recombinant murine polyomavirus (mPy) VP1 and human papillomavirus type 11 (HPV11) L1 capsomeres bound the karyopherin heterodimer alpha2beta1 in vitro in a nuclear localization signal (NLS)-dependent manner. Because the amino acid sequence comprising the NLS of VP1 and L1 overlaps the previously identified DNA binding domain, we examined the relationship between karyopherin and DNA binding of both mPy VP1 and HPV11 L1. Capsomeres of L1, but not VP1, bound by karyopherin alpha2beta1 or beta1 alone were unable to bind DNA. VP1 and L1 capsomeres could bind both karyopherin alpha2 and DNA simultaneously. Both VP1 and L1 capsomeres bound by karyopherin alpha2beta1 were unable to assemble into capsids, as shown by in vitro assembly reactions. These results support a role for karyopherins as chaperones in the in vivo regulation of viral capsid assembly.