Background MODEL-HD is a collaborative effort involving CHDI, FDA and the HD research community to develop a disease progression model for Huntington's Disease. Disease progression models like the one here envisaged are considered good tools to plan clinical research and to help to simulate clinical trials.

Methods/techniques Competing models (based on nonlinear mixed effects and other modelling techniques) are being fit to a combined data set using data from observational studies (REGISTRY, COHORT, PREDICT, TRACK and ENROLL) and selected clinical trials (CARE, Horizon, and others as they become available). These models are being developed by a team of experienced modellers (the MODEL-HD working group) and are under review by an advisory committee made up of HD scientists and clinical experts.

Results/outcome We present our current base model for the age at first appearance and rate of progression of selected signs and symptoms of HD as functions of age and CAG length fit to data from REGISTRY, COHORT and other studies (as appropriate).

Discussion We will discuss opportunities for future work that will be built upon this base model by attempting to include genetic, environmental, and life-style related variables that explain variability in disease progression and by attempting to characterise the diverse patterns of disease progression that appear in the study populations.