Using a meta-narrative literature review and focus groups with key stakeholders to identify perceived challenges and solutions for generating robust evidence on the effectiveness of treatments for rare diseases

INTRODUCTION

For many rare diseases, strong analytic study designs for evaluating the efficacy and effectiveness of interventions are challenging to implement because of small, geographically dispersed patient populations and underlying clinical heterogeneity. The objective of this study was to integrate perspectives from published literature and key rare disease stakeholders to better understand the perceived challenges and proposed methodological approaches to research on clinical interventions for rare diseases.

METHODS

We used a meta-narrative literature review and focus group interviews with key rare disease stakeholders to better understand the perceived challenges in generating and synthesizing treatment effectiveness evidence, and to describe various research methods for mitigating these identified challenges. Data from both components of this study were synthesized narratively according to research paradigms that emerged from our data.

RESULTS

Results from our meta-narrative literature review and focus group interviews revealed three fundamental challenges in generating robust treatment effectiveness evidence for rare diseases: i) limitations in recruiting a sufficient sample size to achieve planned statistical power; ii) inability to account for clinical heterogeneity and assess treatment effects across a clinical spectrum; and iii) reliance on short-term, surrogate outcomes whose clinical relevance is often unclear. We mapped these challenges and associated solutions to three interrelated research paradigms: i) explanatory evidence generation; ii) comparative effectiveness/pragmatic evidence generation; and iii) patient-oriented evidence generation. Within each research paradigm, numerous criticisms and potential solutions have been described with respect to overcoming these challenges from a research study design perspective.

CONCLUSIONS

Over time, discussions about clinical research for interventions for rare diseases have moved beyond methodological approaches to overcome challenges related to explanatory evidence generation, with increased recognition of the importance of pragmatic and patient-oriented evidence. Future directions for our work include developing a framework to expand current evidence synthesis practices to take into consideration many of the concepts discussed in this paper.

Evaluation and validation of diagnostic tests for guiding therapeutic decisions

The term "theranostics" characterizes a particular combination of the coupled use of a drug therapy with a diagnostic test (called "companion diagnostics"). The diagnostic test marks out the technical means used to identify a biomarker which allows for adjusting the use of the new drug.Theranostics promise a significant step forward for the use of personalized medicine, better tailored for patients in terms of efficacy and tolerance. The development process of theranostics is complex since it requires a proper phasing from development to reimbursement, through a collaborative and controlled approach.The task force's recommendations should form the basis for reflection and action amongst the different players in the field of the development of theranostics.All stages of the system meeting heterogeneous and asynchronous rules should be harmonized to allow for simultaneous availability of, and access to the drug and test. Nevertheless, it is necessary to simplify the regulations to enable a better adaptation of theranostics to the speed of innovation.