Clinical Trials Search — ClinicalTrials.gov API

ClinicalTrials.gov is the NIH NLM registry of ~500K clinical studies worldwide — interventional trials, observational studies, expanded-access records. This clinical trials search actor queries the public v2 API by condition, intervention, sponsor, location, status, and date range and returns one structured record per study (NCT ID, phase, sponsor, locations, dates, summary).

Fully keyless. No auth, no proxy, no captcha. Polite-pool only — a 150ms inter-page delay is baked in.

What it returns

One record per clinical trial. Real sample from a 2026-09-01 smoke run on input {"condition":"cancer","intervention":"pembrolizumab","overallStatus":["RECRUITING"],"maxItems":2} (run id qoYyrUpCqXDhPT2cx, dataset gAGapZOQTdW1TXlQ7):

{
  "nctId": "NCT06557889",
  "briefTitle": "Reduction in the Number of Chemotherapy Cycles in Combination With Pembrolizumab in First-line Treatment of PD-L1-positive Recurrent or Metastatic Head and Neck Squamous Cell Carcinomas",
  "officialTitle": "Reduction in the Number of Chemotherapy Cycles in Combination With Pembrolizumab in First-line Treatment of PD-L1-positive Recurrent or Metastatic Head and Neck Squamous Cell Carcinomas",
  "overallStatus": "RECRUITING",
  "phase": "PHASE2",
  "studyType": "INTERVENTIONAL",
  "conditions": "Squamous Cell Carcinoma of Head and Neck",
  "interventions": "DRUG: Pembrolizumab + Cisplatin/Carboplatin + 5-FU",
  "sponsor": "Institut Claudius Regaud",
  "collaborators": "",
  "locations": "CHU Amiens, Amiens, France; Institut Sainte Catherine, Avignon, France; Chu Bordeaux - Hopital Saint André, Bordeaux, France; Centre Jean Perrin, Clermont-Ferrand, France; Centre Oscar Lambret, Lille, France; Chu Limoges, Limoges, France; Centre Hospitalier Regional de Marseille, Marseille, France; CHU de Nantes, Nantes, France; Centre Antoine Lacassagne, Nice, France; Chu de Nimes, Nîmes, France; CHU Poitiers, Poitiers, France; Centre Eugène Marquis, Rennes, France; Clinique Pasteur, Toulouse, France; IUCT-O, Toulouse, France",
  "startDate": "2024-10-21",
  "completionDate": "2030-09",
  "lastUpdatePostDate": "2026-02-11",
  "briefSummary": "This is a phase II, prospective, non-randomized, single-arm, multicentric study to evaluate the activity and safety of treatment with 4 cycles (instead of 6) of chemotherapy (platinum (cisplatin or carboplatin) and 5-Fluorouracil) in combination with pembrolizumab for the first-line treatment of CPS PD-L1 positive recurrent or metastatic head and neck squamous cell carcinoma. A total of 86 patients will have to be enrolled in this study.",
  "url": "https://clinicaltrials.gov/study/NCT06557889",
  "fetchedAt": "2026-09-01T23:47:14.000Z"
}

Input

Matches the actor's INPUT_SCHEMA.json exactly:

Field	Type	Required	Default	Description
condition	string	one of four	"cancer"	Condition or disease (query.cond). E.g. lung cancer, diabetes, asthma.
intervention	string	optional	""	Drug, procedure, device (query.intr). E.g. pembrolizumab, aspirin.
sponsor	string	optional	""	Lead sponsor or collaborator (query.spons). E.g. NIH, Pfizer.
location	string	optional	""	Geographic filter (query.locn). E.g. California, Tokyo, Brazil.
overallStatus	string[]	optional	["RECRUITING"]	Status filter (filter.overallStatus). Allowed: RECRUITING, ACTIVE_NOT_RECRUITING, COMPLETED, NOT_YET_RECRUITING, TERMINATED, WITHDRAWN, SUSPENDED, ENROLLING_BY_INVITATION, NOT_YET_AVAILABLE.
maxItems	integer	optional	25	Maximum records across all pages (1–250). API page size is 50.

At least one of condition / intervention / sponsor / location must be non-empty; otherwise the actor fails fast.

Example input:

{
  "condition": "lung cancer",
  "intervention": "pembrolizumab",
  "overallStatus": ["RECRUITING", "ACTIVE_NOT_RECRUITING"],
  "location": "California",
  "maxItems": 10
}

How it works

A paginated async loop over https://clinicaltrials.gov/api/v2/studies. Up to 50 studies per API page; the actor walks nextPageToken until maxItems is reached or the token disappears. A 150ms delay sits between paginated calls. Each study is projected to a flat record and pushed to the dataset.

Run

make install
make run        # local smoke against INPUT_SCHEMA.json
make push       # build + push to Apify
make run-prod   # cloud smoke on the published build

Limits and gotchas

• Polite use only. ClinicalTrials.gov guidance is ~50 requests/min/IP. The actor is single-call-per-run by design; paginating beyond maxItems=250 requires an external loop.
• overallStatus values are filtered. Unknown enum values are silently dropped; if every value is dropped, the field defaults back to ["RECRUITING"].
• Field joins. interventions, conditions, collaborators, and locations are semicolon-joined strings; each list element keeps the API's compound shape (e.g. DRUG: Pembrolizumab + Cisplatin/Carboplatin + 5-FU).
• Dates. startDate and completionDate are YYYY-MM-DD if known, else YYYY-MM. lastUpdatePostDate is the last time the record was amended.

License

ClinicalTrials.gov is a US NIH NLM public service; metadata is in the public domain.