Optimizing the Design of Clinical Trials to Evaluate the Efficacy of Function-Promoting Therapies.

Background: Several candidate molecules that may have application in treating physical limitations associated with aging and chronic diseases are in development. Challenges in the framing of indications, eligibility criteria, and endpoints and the lack of regulatory guidance have hindered the development of function-promoting therapies.

Methods: Experts from academia, pharmaceutical industry, National Institutes of Health (NIH), and Food and Drug Administration (FDA) discussed optimization of trial design including the framing of indications, eligibility criteria, and endpoints.

Results: Mobility disability associated with aging and chronic diseases is an attractive indication because it is recognized by geriatricians as a common condition associated with adverse outcomes, and it can be ascertained reliably. Other conditions associated with functional limitation in older adults include hospitalization for acute illnesses, cancer cachexia, and fall injuries. Efforts are underway to harmonize definitions of sarcopenia and frailty. Eligibility criteria should reconcile the goals of selecting participants with the condition and ensuring generalizability and ease of recruitment. An accurate measure of muscle mass (eg, D3 creatine dilution) could be a good biomarker in early-phase trials. Performance-based and patient-reported measures of physical function are needed to demonstrate whether treatment improves how a person lives, functions, or feels. Multicomponent functional training that integrates training in balance, stability, strength, and functional tasks with cognitive and behavioral strategies may be needed to translate drug-induced muscle mass gains into functional improvements.

Conclusions: Collaborations among academic investigators, NIH, FDA, pharmaceutical industry, patients, and professional societies are needed to conduct well-designed trials of function-promoting pharmacological agents with and without multicomponent functional training.