📣 New manuscript published from the Medicus Economics, LLC team!
📑 Aromatic L-amino acid decarboxylase deficiency (AADCd) is an ultra-rare genetic disorder characterized by movement disorders, motor and autonomic dysfunction, and developmental delays. Eladocagene exuparvovec-tneq (KEBILIDI), approved for treatment of AADCd by the US FDA in November 2024, has demonstrated long-term improvement in motor function in clinical studies that enrolled N=30 patients without head control at baseline. The primary endpoint in two of the studies was a five-level classification of motor milestones (no motor function, full head control, sitting unassisted, standing with support, and walking with assistance), based on 5 items of a 241-item modified version of the Peabody Developmental Motor Scales-Second Edition (PDMS-2) collected in the studies. The endpoint was selected based on feedback from the FDA and EMA, concerning uncertainty in the meaningful score difference (MSD - aka minimal clinically important difference [MCID]) of the Total PDMS-2 score in AADCd.
📊 In a recent Orphanet publication, Medicus Economics, LLC colleagues Jon Woolley, Marjorie Crowell, and Thomas O'Connell worked with co-authors and PTC Therapeutics to estimate the MSD of the Total PDMS-2 score in AADCd, applying anchor-based methods as recommended in current US FDA guidance on incorporating clinical outcome assessments (COAs) into endpoints for regulatory decision-making.
📍 THE MAIN POINTS: Anchoring against the five-level motor-milestone classification suggested to be clinically meaningful by FDA and EMA communications, the difference in mean Total PDMS-2 scores between levels was ~45 points. Further, receiver operating characteristic curve (ROC) analysis reflected that a 40-point improvement in Total PDMS-2 score had specificity >0.95 for prediction of motor-milestone improvement, suggesting it may be a conservative estimate of the MSD. Cumulative incidence analyses of achievement of the 40-point MSD vs. of the full head control milestone reflected that the MSD may allow greater responsiveness and earlier detection of change, by capturing a broad range of both gross and fine motor domains.
💡 WHY THIS MATTERS: This research illustrates methods that may help characterize evidence from novel endpoints collected in clinical studies of treatments for ultra-rare diseases.
📖 Check out the manuscript here: https://lnkd.in/gvaKXSeN