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Condition (MeSH)

Down Syndrome

ClinicalTrials.gov lists 431 trials for Down Syndrome or a narrower condition beneath it.

MeSH D004314 Nervous System Diseases C10 C16 Listed by Orphanet as a rare disease
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Phase 1 Phase 1 12 Phase 1/2 Phase 1/2 4 Phase 2 Phase 2 33 Phase 2/3 Phase 2/3 2 Phase 3 Phase 3 15 Phase 4 Phase 4 6 Not applicable Not applicable 216 Observational Observational 143 Phase 1 Phase 1 12 Phase 1/2 Phase 1/2 4 Phase 2 Phase 2 33 Phase 2/3 Phase 2/3 2 Phase 3 Phase 3 15 Phase 4 Phase 4 6 Not applicable Not applicable 216 Observational Observational 143

Trials per phase (log scale)

431 of the 431 trials are tagged with Down Syndrome itself; the rest are tagged with a narrower condition beneath it.

Get the Down Syndrome report as a PDF

The PDF carries up to 50 rows of each section, where the page shows the first few, with the sources listed. Enter a work email and confirm it from the message we send, and the report follows by email.

When did Down Syndrome trials start? (27)

Shown in this order: most recent first, 1990 onwards. 2026 is partial: trials registered with a 2026 start date so far, not a full year.

Trials over time, by phase

  • Phase 1
  • Phase 1/2
  • Phase 2
  • Phase 2/3
  • Phase 3
  • Phase 4
  • Not applicable
  • Observational

Top of scale: 49

2000: 2 trials (Phase 3 1, Phase 2/3 1) 2001: 2 trials (Observational 1, Not applicable 1) 2002: 1 trials (Phase 3 1) 2003: 1 trials (Observational 1) 2004: 2 trials (Observational 2) 2005: 4 trials (Observational 1, Not applicable 2, Phase 2 1) 2006: 6 trials (Observational 2, Not applicable 4) 2007: 5 trials (Observational 1, Not applicable 2, Phase 2 1, Phase 1 1) 2008: 8 trials (Observational 3, Not applicable 1, Phase 4 1, Phase 3 2, Phase 2 1) 2009: 13 trials (Observational 11, Phase 2 1, Phase 1/2 1) 2010: 11 trials (Observational 3, Not applicable 5, Phase 3 1, Phase 2 1, Phase 1 1) 2011: 6 trials (Observational 4, Phase 3 1, Phase 1 1) 2012: 16 trials (Observational 8, Not applicable 4, Phase 3 1, Phase 2 2, Phase 1 1) 2013: 19 trials (Observational 10, Not applicable 6, Phase 2 2, Phase 1/2 1) 2014: 13 trials (Observational 7, Not applicable 4, Phase 2 2) 2015: 18 trials (Observational 7, Not applicable 7, Phase 3 1, Phase 2 1, Phase 1 2) 2016: 13 trials (Observational 4, Not applicable 6, Phase 2 2, Phase 1 1) 2017: 14 trials (Observational 6, Not applicable 7, Phase 2 1) 2018: 25 trials (Observational 9, Not applicable 15, Phase 2 1) 2019: 24 trials (Observational 8, Not applicable 15, Phase 3 1) 2020: 17 trials (Observational 5, Not applicable 7, Phase 4 1, Phase 2/3 1, Phase 2 3) 2021: 33 trials (Observational 14, Not applicable 16, Phase 4 1, Phase 2 2) 2022: 19 trials (Observational 4, Not applicable 10, Phase 4 1, Phase 3 1, Phase 2 1, Phase 1/2 2) 2023: 40 trials (Observational 5, Not applicable 28, Phase 3 1, Phase 2 5, Phase 1 1) 2024: 32 trials (Observational 5, Not applicable 25, Phase 1 2) 2025: 49 trials (Observational 10, Not applicable 35, Phase 3 3, Phase 2 1)

Trials registered with a start date in each year, 1990 onward, stacked by phase (complete years only; the current partial year is in the table's notes). The table below lists the same counts, most recent years first.

Trials started per year
Year Trials started
2026 (partial year) 33
2025 49
2024 32
2023 40
2022 19
2021 33
2020 17
2019 24
2018 25
2017 14

Showing 10 of 27 earlier years.

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Forecast of the full-year count, planned starts included, not rows of this table: about 43 trials starting in 2026 and about 44 in 2027, the average of the 24 months through September, counted as registered and carried forward, with about 0.7 times the starts already registered for the rest of 2026 added. The rows of this table count trials registered so far with a start date in the year, planned starts included; the forecast looks ahead to the count for the whole year, so it is not the same measure. In backtests on conditions of this size, forecasts made part-way through the year were typically off by about 15 percent and ran about 1 percent high against the count later registered; forecasts made before the year began were off by about 26 percent and ran about 20 percent low against the count later registered. The part-way figures are from forecasts that used a multiple fitted only on earlier years. These figures rest on a few years of history (target years from 2018 to 2025, varying by figure), place each condition as it is mapped today rather than as it was then, and score against a count for the newest year that was still being revised. Only condition series were scored.

Prediction, not a registry value: median of 36 months from start to primary completion across 42 trials still running at the 2026-10-09 snapshot; registered median of 19 months across 267 trials with a primary completion typed Actual. Source: ClinicalTrials.gov / AACT (CTTI), public domain.

What phase are Down Syndrome trials in? (8)

Shown in this order: phase order.

Show the trials by phase as a table
Trials by phase
Phase Trials
Phase 1 12
Phase 1/2 4
Phase 2 33
Phase 2/3 2
Phase 3 15
Phase 4 6
Not applicable 216
Observational 143

How many Down Syndrome trials are recruiting? (8)

Shown in this order: the order a trial moves through, from not yet recruiting to unknown.

Trials by recruitment status
Status Trials
Not yet recruiting 18
Recruiting 73
Enrolling by invitation 6
Active, not recruiting 15
Completed 246

Showing 5 of 8 statuses.

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Status as registered on ClinicalTrials.gov. Each trial is counted once.

Which lead sponsors run the most Down Syndrome trials? (3)

Shown in this order: most trials first. Lead sponsors the registry classes as industry, NIH, US federal, other government or network. A hospital or university the registry files as government can appear here. Sponsors it classes as academic or other are shown on the full page, because that class cannot separate an institution from a named investigator.

Lead sponsors
Sponsor Trials
Natera, Inc. 8
Sequenom, Inc. 8
Hoffmann-La Roche 7

Which drugs are being tested for Down Syndrome? (5)

Shown in this order: most trials first. One row per drug, matched to a single molecule under all its names, ranked by number of trials.

Drugs tested
Drug Trials
RG1662 4
MERCAPTOPURINE 4
(CP-6890,550) Tofacitinib 3
Cytoxan 3
Asparaginase Erwinia Chrysanthemi 3

Interventions as named in the registry (10)

Shown in this order: most trials first.

Interventions as named in the registry
Drug Trials
Cytarabine IT 5
Donepezil HCI (drug) 5
Conventional Therapy 5
memantine ER 4
HD- Methotrexate (MTX) 4

Showing 5 of 10 interventions.

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These are the names sponsors entered on ClinicalTrials.gov that we have not matched to a single molecule. Some are drugs under a brand or code name; others are procedures, doses or arm labels.

Which serious adverse events do Down Syndrome trials report? (10)

Shown in this order: most subjects affected first. Subjects affected summed across trials, a cross-trial signal, not a rate.

Serious adverse events in this condition's trials
Adverse event Subjects affected Trials
Sepsis 35 3
Respiratory failure 18 3
Death NOS 16 1
Infections and infestations 14 1
Respiratory, thoracic and mediastinal disorders 11 1

Showing 5 of 10 adverse events.

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Which publications cover Down Syndrome? (582)

Shown in this order: major-topic papers first, then newest, then most linked to trials.

Publications
Publication Journal Year Major topic
Caregiver Interviews Regarding Health in Down Syndrome. American journal of medical genetics. Part A 2026 Yes
Antibody concentration and function following SARS-CoV-2 vaccination decrease with age in adults and children with Down syndrome. Vaccine 2026 Yes
Blunted Exercise Pressor Response to Isometric Knee Extension and Post-Exercise Ischemia in Individuals with Down Syndrome. Medicine and science in sports and exercise 2025 Yes
Successful (and Unsuccessful) Recruitment Approaches and Participant Loss in a Down Syndrome Survey. American journal on intellectual and developmental disabilities 2025 Yes
Babble Boot Camp for Infants With Down Syndrome: Piloting a Proactive, Caregiver-Led Intervention Designed to Boost Earliest Speech and Language Skills. American journal of speech-language pathology 2025 Yes

Showing 5 of 582 publications.

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Prevalence (72)

Shown in this order: jurisdiction, then disease name. Orphanet observation for the mapped ORPHA concept; the mapping relation column says whether that concept is exactly this condition or broader or narrower.

Prevalence
Orphanet disease Type Class Geography Jurisdiction Mapping relation
Down syndrome Point prevalence 6-9 / 10 000 United Kingdom GB Unspecified
Down syndrome Point prevalence 6-9 / 10 000 United Kingdom GB Exact
Down syndrome Prevalence at birth 6-9 / 10 000 United Kingdom GB Exact
Down syndrome Prevalence at birth 6-9 / 10 000 United Kingdom GB Unspecified
Down syndrome Point prevalence 6-9 / 10 000 United Kingdom GB Exact

Showing 5 of 72 prevalence observations.

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Rare-disease identity (2)

Shown in this order: exact, broader, narrower, other.

Rare-disease identity
Orphanet disease ORPHA code Relation Source
Down syndrome 870 Exact Orphadata Science knowledge files, Product 1
Down syndrome 870 Exact Orphanet Rare Disease Ontology (ORDO)

Not on this page

Not measured: delivery record.

Checked, with nothing recorded for this condition: sub-conditions in mesh.

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