PROJECT SUMMARY.
Down syndrome (DS), the genetic condition caused by trisomy 21 (T21), is a leading cause of intellectual and
developmental disability, with an estimated prevalence of 1 in 700 live births. Individuals with DS display
increased risk of numerous co-occurring neurological conditions including autism, seizure disorders, and
Alzheimer’s disease (AD). Recently, an increasing number of reports have documented individuals with DS
displaying a condition known as Down Syndrome Regression Disorder (DSRD), which include symptoms such
as catatonia, mutism, depersonalization, loss of ability to perform activities of daily living, hallucinations,
delusions, and aggression. The etiology of DSRD is unclear, with affected individuals being subjected to highly
heterogenous diagnostic work ups and disparate therapeutic interventions, including psychiatric medications
(e.g., Lorazepam), electroconvulsive therapy (ECT), and intravenous immunoglobulin (IVIG). Therefore,
additional research into the etiology of DSRD and the relative efficacy of different therapies is clearly needed.
We propose here a comprehensive clinical research program that will not only advance our understanding of
DSRD etiology, but which would also provide important information about the relative safety and efficacy of three
different therapeutic approaches. Importantly, we hypothesize that many DSRD cases are driven by immune
dysregulation affecting the central nervous system (CNS) and that these cases will benefit from immune-
based therapies. Therefore, we propose to complete a comparative mechanistic investigation of three potential
DSRD therapies: the benzodiazepine Lorazepam, IVIG, and the JAK inhibitor Tofacitinib. Our Specific Aims are:
1. To define the relative safety profile of Lorazepam, IVIG, and Tofacitinib in DSRD. We will complete a
randomized, open-label, Phase II clinical trial for Lorazepam, IVIG, and Tofacitinib in individuals with DSRD with
the primary endpoint being safety.
2. To compare the efficacy of Lorazepam, IVIG, and Tofacitinib in DSRD. Using key metrics for the evaluation
of individuals with DSRD, a suite of secondary and tertiary endpoints will assess improvements in overall
neurological health, activities of daily living, and quality of life, as well as domain-specific improvements in
catatonia, movement and motor function, speech, sleep, and cognition.
3. To investigate potential mechanisms underlying DSRD and its response to therapies. Using
biospecimens from individuals affected by DSRD collected during the trial and control samples from a companion
active cohort study of individuals with DS, we will define biosignatures associated with DSRD diagnosis and the
impact of each treatment modality on these biosignatures.
Results from this phase II trial will generate much needed insights into DSRD etiology and treatment, paving the
road for future larger trials to fulfill an unmet need in the DS community.