Response to Regulatory Questions (RTQ), published by HL7 International. This guide is not an authorized publication; it is the continuous build for version 0.1.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/HL7/rtq-ig/ and changes regularly. See the Directory of published versions

Use Case

The Response to Regulatory Questions (RTQ) Implementation Guide defines structured FHIR profiles on Questionnaire and QuestionnaireResponse that turn regulatory questions and answers into fully machine-readable, interoperable data. By embedding CTD codes, due dates, sender/recipient information, and rich metadata directly into the resources, RTQ replaces unstructured PDF/Word/email exchanges with a standardized format that enables end-to-end automation, predictive analytics, and global harmonization.

This structured approach delivers transformative benefits for both health authorities and industry, dramatically reducing manual effort, and enabling proactive regulatory strategies.

Visual Workflow: The RTQ Loop

sequenceDiagram
    autonumber
    participant Regulator as Health Authority
    participant Gateway as Regulatory Gateway
    participant SponsorSys as Sponsor RIM/Safety System
    participant Admin as Triage Agent (AI/Human)
    participant Expert as SME (CMC/Clinical)

    Note over Regulator, SponsorSys: Standardized Question

    Regulator->>Gateway: Issue Question (Questionnaire)
    Gateway->>SponsorSys: Forward via API/Message
    SponsorSys->>SponsorSys: Parse CTD Codes & Metadata

    rect rgb(240, 248, 255)
    Note over SponsorSys, Expert: Automated Triage & Draughting
    SponsorSys->>Admin: Alert: New Priority Question
    Admin->>SponsorSys: Search Knowledge Base
    SponsorSys-->>Admin: Suggest Similar Past Responses (95% Match)
    Admin->>Expert: Assign Task with Draft
    end

    Expert->>Expert: Review & Finalize Response
    Expert->>SponsorSys: Approve Response (QuestionnaireResponse)

    Note over Regulator, SponsorSys: Structured Reply

    SponsorSys->>Gateway: Submit Response (QuestionnaireResponse)
    Gateway->>Regulator: Ingest & Route to Assessor

Real-World Scenarios

Scenario A: The 24-Hour Clarification (Speed)

Context: During a Type II variation review, the EMA reviewer notices a minor discrepancy in the reported batch numbers for a stability study.

• Old Way: Reviewer drafts an email/PDF. EMA admin sends it. Sponsor admin receives it next day, manually logs it, emails CMC lead. CMC lead checks data, drafts email reply. Sponsor admin formats to PDF, sends back. Total time: 3-5 days.
• RTQ Way: Reviewer types question into a FHIR-compliant structured authoring system. RTQ Questionnaire is generated, added to an APIX Task (refer to APIX IG for detail), and sent to the sponsor via API. Sponsor system receives it instantly, reads CTD code 3.2.P.8, and auto-assigns to the Stability Lead via Teams/Slack. Lead confirms batch number in the system, clicks "Approve" on the auto-drafted correction. Response sent. Total time: < 2 hours.
  Note: Regulators can also send the RTQ Questionnaire via email if they do not yet have an APIX-compliant system.

Scenario B: The Complex Clinical Query (Reuse)

Context: The FDA asks a complex question about efficacy in a specific elderly sub-population for a new oncology drug.

• Old Way: Clinical team treats it as a new request. Starts analysis from scratch. Weeks of work. Risk of inconsistency with answers given to PMDA (Japan) last month.
• RTQ Way: When the question arrives, the Sponsor's AI agent scans the Questionnaire text and semantic meaning against the global RTQ repository. It finds a 92% match with a response sent to PMDA 4 weeks ago. The system presents this previous answer to the Clinical Lead. One minor edit for US-specific context, and the response is ready. Result: Consistent global regulatory position and 90% effort reduction.

Key Benefits and Use Cases