LCFA Next Breath · Developer API

Build on the LCFA trial database

A public REST API over 14,500+ lung cancer clinical trials — sourced from ClinicalTrials.gov and 19 pharmaceutical registries, enriched with structured biomarkers and geocoded sites. Free for non-commercial use; request a key below.

Quickstart

Every request (except this page and /api/v1/docs) needs an API key. Pass it as a bearer token:

curl -H "Authorization: Bearer lcfa_pk_..." \
  "https://lcfa-trial-finder.vercel.app/api/v1/trials?limit=5"

Successful responses use a consistent envelope:

json

{
  "data": [ /* array of trial objects */ ],
  "meta": {
    "total": 14534,
    "limit": 50,
    "offset": 0,
    "quota_used": 17,
    "quota_limit": 1000
  }
}

Check X-RateLimit-Limit and X-RateLimit-Remaining response headers, or hit /api/v1/meta for a quota snapshot without spending a call.

Rate limits

Daily quotas reset at UTC midnight. When you hit the limit you'll get a 429 with Retry-After set to seconds until reset. Tiers:

Tier	Daily quota	Who it's for
Free	100 requests/day	For personal or evaluation use. Any researcher or individual developer.
Standard	1,000 requests/day	For patient-advocacy apps, research dashboards, and production nonprofit tools.
Partner	10,000 requests/day	Negotiated. For high-volume integrators and LCFA partner organizations.

Error responses: 401 missing/invalid key · 403 revoked · 429 quota exceeded.

Endpoints

GET/api/v1/trials

Search trials. Supports diagnosis, location, biomarker, mutation, phase, status, age/gender, and ZIP-radius filters. Paginated. Returns a 5-location sample per trial.

Query parameters (16)

diagnosisType: nsclc | sclc | unknown (default: unknown)
cancerStage: SCLC only: limited | extensive — restricts results to that stage. Inclusive: rows that mention the chosen stage OR have no stage signal at all are included; rows that explicitly mention the opposite stage are excluded.
country: us | international
state: Two-letter US state code (e.g. CA)
gender: male | female
age: Integer (years)
trialPhase: Phase I | Phase II | Phase III | Phase IV | Interventional | Observational | All Phases
trialStatus: Recruiting | Enrolling | Active | Completed | Closed
statusBuckets: Comma-separated: recruiting,active,completed,unknown (default: recruiting,active,unknown)
biomarkers: Comma-separated: EGFR, ALK, ROS1, KRAS, BRAF, MET, RET, NTRK, HER2, PD-L1
mutations: biomarker:mutationId pairs, e.g. EGFR:L858R,KRAS:G12C
firstPostedAfter: ISO date (YYYY-MM-DD) — only trials first posted on/after this date
zip: US ZIP code (5 digits) — requires radius
radius: Miles (max 500) — requires zip
limit: Integer 1-200 (default 50)
offset: Integer (default 0)

GET/api/v1/trials/:nct_id

Full detail for a single trial, including inclusion/exclusion criteria, outcomes, all locations with lat/lng, and structured biomarker requirements.

GET/api/v1/sources

List of data sources (ClinicalTrials.gov + 19 pharma registries) with approximate trial counts.

GET/api/v1/meta

Returns the calling key's label, tier, and today's quota usage. Does NOT count against the quota — safe to poll.

GET/api/v1/docs

Machine-readable JSON version of this documentation. Unauthenticated.

Examples

Save your key to an env var first (export LCFA_KEY=lcfa_pk_...), then:

Recruiting EGFR-L858R trials in California

Most common concrete use-case — biomarker + location filter.

curl -H "Authorization: Bearer $LCFA_KEY" \
  "https://lcfa-trial-finder.vercel.app/api/v1/trials?trialStatus=Recruiting&biomarkers=EGFR&mutations=EGFR:L858R&state=CA&limit=10"

Trials within 50 miles of ZIP 94103

ZIP-radius search. US only; 97.7% of trial sites are geocoded.

curl -H "Authorization: Bearer $LCFA_KEY" \
  "https://lcfa-trial-finder.vercel.app/api/v1/trials?zip=94103&radius=50&limit=20"

Full detail for one trial

Includes inclusion/exclusion criteria, all sites with lat/lng, and biomarkers.

curl -H "Authorization: Bearer $LCFA_KEY" \
  "https://lcfa-trial-finder.vercel.app/api/v1/trials/NCT02193282"

Check your remaining quota

Does NOT count against your daily quota. Safe to poll.

curl -H "Authorization: Bearer $LCFA_KEY" \
  "https://lcfa-trial-finder.vercel.app/api/v1/meta"

Response fields

List endpoint

GET /api/v1/trials returns each trial with these fields:

nct_idofficial_titlebrief_summaryphasestatussponsorconditionsurlpharma_urlpharma_source_slugstudy_typestudy_startfirst_postedprimary_completionlast_updatedlocation_countlocations_sample

Detail endpoint

GET /api/v1/trials/:nct_id adds these on top of the list fields:

detailed_descriptionconditions_arrinterventionenrollmentage_minage_maxsexes_eligibleinclusion_criteriaexclusion_criteriamesh_termskeywordsstudy_completionsourceplain_language_summaryprimary_outcomessecondary_outcomesstudy_documentspublicationslocationsbiomarkers

Data sources + freshness

Trial records come from ClinicalTrials.gov (NIH) plus 19 pharmaceutical sponsor registries (AstraZeneca, Genentech/Roche, Pfizer, Merck/Daiichi, Novartis, and others). The dataset is refreshed monthly via an orchestrated pipeline (CT.gov API sync → pharma CSV import → HTTP + Firecrawl scrape → GPT-4o biomarker extraction → Nominatim geocoding → auto-flag).

Current coverage: 14,534 trials, 376K trial sites (97.7% geocoded), 7,704 structured biomarker requirements across 3,383 trials, with mutation-level granularity for EGFR, KRAS, BRAF, MET, ALK/ROS1/RET fusions, and PD-L1 expression.

Fetch GET /api/v1/sources for a live list of sources with per-source trial counts.

Terms of use

Attribution is required: “Trial data via LCFA Next Breath (lcfa-trial-finder.vercel.app)” on any public surface using this data.
Do not present API output as medical advice. Always link patients back to ClinicalTrials.gov or the original sponsor page (we include the url field on every trial).
Don't re-host the full dataset as a competing database. Building search, decision support, notification, and analytics tools is encouraged.
Respect your quota. If you need more, request a Partner tier.

Request a key

Ready to build? Email us.

We manually provision every key — this keeps the service focused on legitimate patient-advocacy, research, and nonprofit use. Tell us who you are and what you're building, and we'll usually respond within a few business days.

Email trials@lungcancerfoundation.org →

Include: organization name, what you're building, and expected daily request volume.

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