Challenges in Research and Health Technology Assessment of Rare Disease Technologies: Report of the ISPOR Rare Disease Special Interest Group.

BACKGROUND: Successful development of new treatments for rare diseases (RDs) and their sustainable patient access require overcoming a series of challenges related to research and health technology assessment (HTA). These impediments, which may be unique to RDs or also apply to common diseases but are particularly pertinent in RDs, are diverse and interrelated. OBJECTIVE: To develop for the first time a catalog of primary impediments to RD research and HTA, and to describe the cause and effect of individual challenges. METHODS: Challenges were identified by an international 22-person expert working group and qualitative outreach to colleagues with relevant expertise. A broad range of stakeholder perspectives is represented. Draft results were presented at annual European and North American International Society for Pharmacoeconomics and Outcomes Research (ISPOR) congresses, and written comments were received by the 385-strong ISPOR Rare Disease Review Group from two rounds of review. Findings were refined and confirmed via targeted literature search. RESULTS: Research-related challenges linked to the low prevalence of RDs were categorized into those pertaining to disease recognition and diagnosis, evaluation of treatment effect, and patient recruitment for clinical research. HTA-related challenges were classified into issues relating to the lack of a tailored HTA method for RD treatments and uncertainty for HTA agencies and health care payers. CONCLUSIONS: Identifying and highlighting diverse, but interrelated, key challenges in RD research and HTA is an essential first step toward developing implementable and sustainable solutions. A collaborative multistakeholder effort is required to enable faster and less costly development of safe, efficacious, and appropriate new RD therapies that offer value for money.

Patient-Reported Outcome and Observer-Reported Outcome Assessment in Rare Disease Clinical Trials: An ISPOR COA Emerging Good Practices Task Force Report.

BACKGROUND: Rare diseases (RDs) affect a small number of people within a population. About 5000 to 8000 distinct RDs have been identified, with an estimated 6% to 8% of people worldwide suffering from an RD. Approximately 75% of RDs affect children. Frequently, these conditions are heterogeneous; many are progressive. Regulatory incentives have increased orphan drug designations and approvals. OBJECTIVE: To develop emerging good practices for RD outcomes research addressing the challenges inherent in identifying, selecting, developing, adapting, and implementing patient-reported outcome (PRO) and observer-reported outcome (ObsRO) assessments for use in RD clinical trials. GOOD PRACTICES FOR OUTCOMES RESEARCH: This report outlines the challenges and potential solutions in determining clinical outcomes for RD trials. It follows the US Food and Drug Administration Roadmap to Patient-Focused Outcome Measurement in Clinical Trials. The Roadmap consists of three columns: 1) Understanding the Disease or Condition, 2) Conceptualizing Treatment Benefit, and 3) Selecting/Developing the Outcome Measure. Challenges in column 1 include factors such as incomplete natural history data and heterogeneity of disease presentation and patient experience. Solutions include using several information sources, for example, clinical experts and patient advocacy groups, to construct the condition's natural history and understand treatment patterns. Challenges in column 2 include understanding and measuring treatment benefit from the patient's perspective, especially given challenges in defining the context of use such as variations in age or disease severity/progression. Solutions include focusing on common symptoms across patient subgroups, identifying short-term outcomes, and using multiple types of COA instruments to measure the same constructs. Challenges in column 3 center around the small patient population and heterogeneity of the condition or study sample. Few disease-specific instruments for RDs exist. Strategies include adapting existing instruments developed for a similar condition or that contain symptoms of importance to the RD patient population, or using a generic instrument validated for the context of use. CONCLUSIONS: This report provides state-of-the-art solutions to patient-reported outcome (PRO) and observer-reported outcome (ObsRO) assessments challenges in clinical trials of patients with RDs. These recommended solutions are both pragmatic and creative and posed with clear recognition of the global regulatory context used in RD clinical development programs.

Rare Disease Terminology and Definitions-A Systematic Global Review: Report of the ISPOR Rare Disease Special Interest Group.

BACKGROUND: At present, there is no universal definition of rare disease. OBJECTIVE: To provide an overview of rare disease definitions currently used globally. METHODS: We systematically searched for definitions related to rare disease from organizations in 32 international jurisdictions. Descriptive statistics of definitions were generated and prevalence thresholds were calculated. RESULTS: We identified 296 definitions from 1109 organizations. The terms "rare disease(s)" and "orphan drug(s)" were used most frequently (38% and 27% of the definitions, respectively). Qualitative descriptors such as "life-threatening" were used infrequently. A prevalence threshold was specified in at least one definition in 88% of the jurisdictions. The average prevalence threshold across organizations within individual jurisdictions ranged from 5 to 76 cases/100,000 people. Most jurisdictions (66%) had an average prevalence threshold between 40 and 50 cases/100,000 people, with a global average of 40 cases/100,000 people. Prevalence thresholds used by different organizations within individual jurisdictions varied substantially. Across jurisdictions, umbrella patient organizations had the highest (most liberal) average prevalence threshold (47 cases/100,000 people), whereas private payers had the lowest threshold (18 cases/100,000 people). CONCLUSIONS: Despite variation in the terminology and prevalence thresholds used to define rare diseases among different jurisdictions and organizations, the terms "rare disease" and "orphan drug" are used most widely and the average prevalence threshold is between 40 and 50 cases/100,000 people. These findings highlight the existing diversity among definitions of rare diseases, but suggest that any attempts to harmonize rare disease definitions should focus on standardizing objective criteria such as prevalence thresholds and avoid qualitative descriptors.

A survey exploring caregiver burden and health-related quality of life in hereditary transthyretin amyloidosis.

BACKGROUND: Hereditary transthyretin amyloidosis (ATTRv) is an ultra-rare, life-shortening disease with a high unmet need. This study examined ATTRv caregiver health-related quality of life (HRQoL) and productivity. METHODS: A cross-sectional online survey, including EQ-5D-3L, Hospital anxiety and depression scale (HADS), and caregiver and patient characteristics questions, was developed to assess ATTRv caregiver burden. A companion general population survey collected EQ-5D-3L, HADS and chronic health conditions data. Caregiver-control group differences in HRQoL were assessed using t-tests and chi-square tests. Ordinary Least Squares regression was used to estimate the disutility of being a caregiver compared to controls stratified by patient ambulatory status. RESULTS: Thirty-six caregivers and matched controls completed the survey (n = 72). The disease severity of patients they cared for was varied: 33% required no assistance walking, 58% required assistance with walking and 9% required a wheelchair/were bedridden. On average, caregivers spent 6 h daily on practical care and 4 h daily on emotional support. Fifty-six percent indicated that they had changed their employment due to providing ATTRv care. Caregivers reported lower HRQoL, as indicated by lower EQ-5D 3L utility scores (M = 0.772, SD = 0.178 vs. M = 0.849, SD = 0.218) and higher HADS anxiety (9.3 vs. 6.1, p < 0.01) and depression (7.6 vs. 4.4, p < 0.01) scores, compared with matched controls. Caregivers were also more likely to report sleep problems (33% vs. 8%, p < 0.01) and stress (42% vs. 0%, p < 0.001) as chronic conditions than controls. CONCLUSIONS: The study results indicate that caring for a person with ATTRv can have a considerable negative impact on caregivers' HRQoL and productivity. The study findings provide important information for economic evaluations of ATTRv treatments.