integrating-clinical-trials

SOP: integrating clinical trial data from ClinicalTrials.gov

Use this SOP to populate clinical-trials-active: counts on compound and intervention pages, to write “Clinical trials” sections, and to link out to specific NCT studies. All data comes from the ClinicalTrials.gov v2 API (launched 2023, replacing the deprecated v1/classic API).

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When to use this SOP

• Filling the clinical-trials-active: frontmatter field on type: compound or type: intervention pages.
• Checking whether a preclinical compound has entered human trials.
• Writing or updating the “Clinical evidence” / “Clinical trials” section on any compound, intervention, or protein page.
• Periodic refresh (lint pass recommends every ~6 months) to catch new trial registrations.

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ClinicalTrials.gov v2 API

Base URL: https://clinicaltrials.gov/api/v2/ Format: JSON (default) or CSV Authentication: None required for read access. Documentation: https://clinicaltrials.gov/data-api/api

The v2 API replaces the deprecated classic API (/api/query/full_studies). Always use v2.

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Endpoint: search studies

GET https://clinicaltrials.gov/api/v2/studies

Key query parameters:

Parameter	Description	Example
query.cond	Condition/disease keyword	aging
query.intr	Intervention keyword	rapamycin
query.term	Full-text search	mTOR+inhibitor
filter.overallStatus	Status filter	RECRUITING,ACTIVE_NOT_RECRUITING
filter.phase	Phase filter	PHASE2,PHASE3
filter.studyType	Study type	INTERVENTIONAL
pageSize	Results per page (max 1000)	50
nextPageToken	Pagination	from prior response
format	Response format	json

Status values:

• RECRUITING — actively enrolling
• ACTIVE_NOT_RECRUITING — enrolled; data collection ongoing
• COMPLETED — finished
• TERMINATED — stopped early
• WITHDRAWN — registered but never started
• ENROLLING_BY_INVITATION — restricted enrollment

“Active” definition for clinical-trials-active:: Count only RECRUITING + ACTIVE_NOT_RECRUITING trials. Do not count COMPLETED, TERMINATED, or WITHDRAWN.

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Example queries

Count active trials for a compound

curl -s "https://clinicaltrials.gov/api/v2/studies?query.intr=rapamycin&filter.overallStatus=RECRUITING,ACTIVE_NOT_RECRUITING&pageSize=1&format=json" | python3 -c "import sys,json; d=json.load(sys.stdin); print(d.get('totalCount', 'no totalCount field'))"

Note: the v2 API does not return a totalCount field in the standard response — pagination is via nextPageToken. To count results, iterate pages or use a larger pageSize and count the studies array.

Practical approach for a quick count:

# Fetch up to 200 results (typical for a single compound) and count
curl -s "https://clinicaltrials.gov/api/v2/studies?query.intr=rapamycin&filter.overallStatus=RECRUITING,ACTIVE_NOT_RECRUITING&pageSize=200&format=json" | python3 -c "import sys,json; d=json.load(sys.stdin); print(len(d.get('studies', [])))"

Get structured data for the first 3 active trials

curl -s "https://clinicaltrials.gov/api/v2/studies?query.intr=rapamycin&filter.overallStatus=RECRUITING,ACTIVE_NOT_RECRUITING&pageSize=3&format=json"

The confirmed response structure (validated 2026-05-05):

{
  "studies": [
    {
      "protocolSection": {
        "identificationModule": {
          "nctId": "NCT05949658",
          "briefTitle": "Rapalog Pharmacology (RAP PAC) Study",
          "officialTitle": "Safer mTOR Inhibition for Human Geroprotection"
        },
        "statusModule": {
          "overallStatus": "RECRUITING",
          "startDateStruct": {"date": "2024-05-15"},
          "primaryCompletionDateStruct": {"date": "2027-03"}
        },
        "designModule": {
          "studyType": "INTERVENTIONAL",
          "phases": ["PHASE1"],
          "enrollmentInfo": {"count": 72}
        },
        "eligibilityModule": {
          "minimumAge": "55 Years",
          "maximumAge": "89 Years"
        }
      }
    }
  ],
  "nextPageToken": "..."
}

Search by condition + intervention (aging-specific)

# All active longevity/aging-focused trials
curl -s "https://clinicaltrials.gov/api/v2/studies?query.cond=aging&query.intr=rapamycin&filter.overallStatus=RECRUITING,ACTIVE_NOT_RECRUITING&pageSize=20&format=json"
 
# Senolytic trials
curl -s "https://clinicaltrials.gov/api/v2/studies?query.term=senolytic&filter.overallStatus=RECRUITING,ACTIVE_NOT_RECRUITING&pageSize=20&format=json"
 
# Trials targeting a specific gene/pathway via MeSH term
curl -s "https://clinicaltrials.gov/api/v2/studies?query.term=mTOR+inhibitor+aging&filter.studyType=INTERVENTIONAL&pageSize=20&format=json"

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What to record per trial

For any specific trial cited on a wiki page, record in a table or list:

Field	Source in API	Example
NCT ID	identificationModule.nctId	NCT05949658
Phase	designModule.phases	Phase 1
Status	statusModule.overallStatus	Recruiting
Title	identificationModule.briefTitle	Rapalog PAC Study
N	designModule.enrollmentInfo.count	72
Completion	statusModule.primaryCompletionDateStruct.date	2027-03
Sponsor	sponsorCollaboratorsModule.leadSponsor.name	UW-Madison
Age range	eligibilityModule.minimumAge/maximumAge	55–89 years
Primary outcome	outcomesModule.primaryOutcomes[0].measure	pharmacokinetics

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Populating clinical-trials-active: frontmatter

This R22 schema field on type: compound pages is an integer count:

clinical-trials-active: 3   # active trials as of 2026-05-05

Procedure:

1. Query the v2 API with query.intr=<compound name> + filter.overallStatus=RECRUITING,ACTIVE_NOT_RECRUITING.
2. Also try common synonyms (e.g., for rapamycin: sirolimus, rapamycin, eRapa).
3. Sum the unique NCT IDs across synonym searches (deduplicate).
4. Set the field to the total count.
5. Add a comment in the page body: <!-- clinical-trials-active: queried YYYY-MM-DD; recheck in ~6 months -->.

Zero is a valid value. If no active trials are found, set clinical-trials-active: 0 and note the query date.

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Writing a “Clinical trials” section

For compound or intervention pages that have trials, add a section:

## Clinical trials
 
As of YYYY-MM-DD, N active interventional trials are registered (ClinicalTrials.gov,
`filter.overallStatus=RECRUITING,ACTIVE_NOT_RECRUITING`, query: `<search term>`).
 
Selected trials:
 
| NCT ID | Phase | Title (brief) | N | Status | Estimated completion |
|---|---|---|---|---|---|
| NCT05949658 | Phase 1 | Safer mTOR Inhibition for Human Geroprotection | 72 | Recruiting | 2027-03 |
|... |... |... |... |... |... |
 
#gap/long-term-unknown — no Phase 3 or Phase 4 trials registered as of query date.

For pages where trials exist but have not been searched recently, add:

<!-- TODO: re-query ClinicalTrials.gov v2 API; last checked YYYY-MM-DD -->

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Periodic refresh discipline

The clinical-trials-active: field decays over time. The lint pass (sops/lint-pass.md) should flag pages where:

• The <!-- clinical-trials-active: queried... --> comment is older than 6 months.
• The field value differs from a fresh API query result.

Lint check rule: Any compound or intervention page with clinical-trials-active: set should have a query-date comment. Missing comments should be flagged as #gap/trial-count-stale.

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EU Clinical Trials Register (supplementary)

Endpoint: https://www.clinicaltrialsregister.eu/ctr-search/rest/

Some European trials are registered here but not on ClinicalTrials.gov. For geroprotector trials, this matters — European institutions may register EU-CTA without a corresponding ClinicalTrials.gov record.

# Search EU registry by keyword
curl "https://www.clinicaltrialsregister.eu/ctr-search/rest/results?query=rapamycin&page=1"

Note: EU CTA register also hosts completed results data at the per-trial level.

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See also

• finding-aging-specific — DrugAge and ClinicalTrials.gov for intervention context
• finding-compound-data — PubChem, DrugBank, ChEMBL for compound identity
• finding-druggability — Open Targets clinical advance data (complementary trial count source)
• sops/adding-a-claim.md — footnote format for clinical claims