Query ClinicalTrials.gov API v2 for studies by condition and intervention with cursor-based pagination

Steps

1. Construct GET request to https://clinicaltrials.gov/api/v2/studies with query parameters: query.cond (condition/disease), query.intr (intervention), pageSize (max 1000), and optional sort field
2. Parse the JSON response envelope: studies array contains objects with protocolSection, derivedSection, and hasResults boolean; capture nextPageToken from the response root
3. Iterate pages by passing the nextPageToken value as the pageToken parameter in subsequent requests until nextPageToken is absent
4. Extract nested fields from protocolSection (identificationModule for NCT ID and title, statusModule for overall status and phase, eligibilityModule for criteria text) using the published study data structure schema at clinicaltrials.gov/data-api/about-api/study-data-structure
5. For a single full record, call GET https://clinicaltrials.gov/api/v2/studies/{nctId} to retrieve resultsSection including participant flow and adverse events when hasResults is true
6. Validate enumerated status values (RECRUITING, COMPLETED, TERMINATED, etc.) against the API schema rather than hardcoding strings, as the v2 schema enforces controlled vocabulary