Aggregation and analysis of 25 years of prion disease natural history extracted from published literature

Background and Objectives. Prion disease is an untreatable, typically rapidly progressive dementia. New drug candidates designed to lower prion protein are now entering clinical trials. To support future pivotal trials, we sought to assemble and analyze a public dataset of natural history data characterizing the symptomatic course of prion disease in order to provide a quantitative basis for modelling and rational trial design. Methods. We extracted data from medical publications between 2000 and 2024 reporting on n[≥]5 prion disease patients. Information about demographics, ascertainment, and clinical milestones, such as time from onset to death, akinetic mutism, diagnostic testing and outcomes, were extracted for aggregate cohorts of [≥]2 patients and individual patient-level data (PLD). We computed summary statistics of cohorts and PLD, visualized survival through forest plots and Kaplan-Meier curves, analyzed covariates regarding survival, and identified biases and heterogeneity within the literature. Results. From 245 included publications we extracted 418 aggregate cohort medians and 1,400 rows of individual PLD. 90% of cohorts and 91% of individual patients had symptom-to-death milestones, while only 7% and 11% had a time interval from a clinical presentation milestone to death, respectively. Symptom-to-death intervals varied as much as 3.2-fold even between cohorts of the same histopathologic subtype, and akinetic mutism occurred 73% sooner than death when both endpoints were reported (N=53). Indicators of disease severity, such as a cognitive test, were rarely present in either aggregate data (11%) or PLD (6%). Discussion. Data routinely reported in publications can quantify diagnostic delay and covariates affecting survival time, but are limited in ability to inform pivotal trial design because most such data are aggregated, cross-sectional, lack indicators of disease severity, and present timelines beginning with onset rather than more relevant clinical milestones, such as diagnosis, that may better reflect the moment of potential for trial enrollment. There is a need for clinical data to report milestones such as intervals from diagnosis to death, for longitudinal cognitive and functional scores, and for deposition of publicly accessible PLD.