Analyzing HTAs: Surrogate Endpoints in The Respiratory Domain and Applied in Ophthalmology

OBJECTIVES: This study aimed to evaluate historic HTAs for therapeutic products analogous to the IPF/ILD therapeutic domain. The objective was to elucidate the application and HTA body critique of SEs in clinical and economic evidence packages, facilitating insights for refining the validation of SEs in IPF and ILD.

METHODS: Analogous therapeutic products were selected based on pre-defined criteria, with five identified for review. Publicly available HTA reports and methodological guidelines for these analogues were searched and evaluated, including from Canada, England, France, Germany, Netherlands, Scotland, Spain, Sweden, USA, Wales. Key information was extracted into a data extraction table, detailing the outcome, primary decision drivers, and role of SEs in informing the decision. Thematic learnings were then derived from each HTA submission and methodological review. The findings were subsequently tested for feasibility through a systematic literature review-supported surrogacy endpoint validation in glaucoma and diabetic macular oedema.

RESULTS: The review of HTAs revealed considerable variations in the application of SEs and their subsequent critique by HTA agencies. Both Germany and the UK offered comprehensive details regarding the acceptance of SEs. In contrast, other markets provided comparatively limited guidance. Notably, Germany did not approve the use of SEs for any of the drugs evaluated, owing to an absence of validation. The surrogacy validation exercise undertaken in glaucoma and diabetic macular oedema was determined to be feasible and resulted in intuitive outcomes.

CONCLUSIONS: This study underscores the potential role of SEs in HTA submissions and highlights the necessity for their meticulous validation in the IPF/ILD therapeutic domain and beyond. The successful feasibility test further signifies the potential for broadening the application of these findings across other disease areas.