Clinical Trial Design Assistant β Universal
Implementation Plan v1.0
Executive Summary
The Clinical Trial Design Assistant (Universal) is an AI-powered chatbot that helps clinical researchers design rigorous, regulatory-grade clinical trials for any disease, condition, or therapeutic area. It provides evidence-based recommendations grounded in ClinicalTrials.gov, PubMed, and regulatory guidance β serving as a strategic partner across the entire drug development continuum.
Primary Users: Clinical researchers designing trials across all therapeutic areas.
This is a new standalone project, distinct from the PTCL-specific Clinical-Trial-Design-Assistant. Same architecture, universal scope.
1. Problem & Solution Overview
| π¨ Current Challenges | β Our Solution |
|---|---|
| Information Overload β 500,000+ trials make research slow | Evidence-Based Recommendations β Automated retrieval of proven trial designs |
| Therapeutic Complexity β Each disease area has unique design considerations | Universal Expertise β Adapts to any indication, from oncology to gene therapy |
| Regulatory Uncertainty β Unclear reasons for past FDA/EMA outcomes | Regulatory Intelligence β Extracts success factors across jurisdictions |
| Statistical Rigor β Complex specialized expertise required | Statistical Guidance β Sample size, power calculations, endpoint selection |
How It Works:
Clinician types: "Design a Phase 3 trial for relapsed DLBCL with a novel BTK inhibitor"
Chatbot returns:
β Mandatory input confirmation checklist
β Inclusion/exclusion criteria
β Primary endpoint: PFS (with regulatory precedent)
β Sample size: 300β400 (with power calculation)
β Comparator: R-CHOP or investigator's choice
β Regulatory pathway: Breakthrough Therapy + accelerated approval
β Evidence: NCT IDs, PMIDs, regulatory citations
2. Architecture Overview
High-Level Architecture
flowchart LR
classDef large font-size:22px,stroke-width:2px;
A["User Question"]:::large --> B["Claude\nwith Web Search"]:::large
B <--> C["Real-time\nWeb Search"]:::large
C <--> D["ClinicalTrials.gov\n+ PubMed"]:::large
B --> E["Structured\nRecommendations"]:::large
Detailed Processing Flow
flowchart TD
A[User Query] -->|1. Submit question| B[Session Memory Check]
B -->|2. Load context| C["Claude + System Prompt"]
C -->|3. Web search queries| D["ClinicalTrials.gov\n+ PubMed + Regulatory"]
D -->|4. Return search results| C
C -->|5. Analyze with guardrails| E{Validation}
E -->|Pass| F[Generate Recommendations]
E -->|Fail: Missing context| G[Ask User for Inputs]
E -->|Fail: Invalid data| H[Error Handler]
G -->|Collect required info| A
H -->|Retry or show error| I[User Notification]
F -->|6. Format output| J[Streamlit Display]
J -->|7. Store in session| K[Session Memory]
K -->|8. Follow-up?| A
K -->|Done| L[End]
style C fill:#e1f5ff
style E fill:#fff4e1
style F fill:#e8f5e9
style J fill:#f3e5f5
Key Difference from PTCL Version
| PTCL-Specific | Universal |
|---|---|
| Hardcoded disease hierarchy (AITL > ALCL-ALK- > PTCL-NOS) | No hardcoded hierarchy β adapts to user-defined disease |
| Orphan drug fallback with predefined related diseases | "Ask first" approach β Claude requests missing context |
| Fixed comparator categories (GDP, BBv, etc.) | Dynamic comparator framework (SOC, active, placebo, synthetic) |
| PTCL-specific validation (TCL disease match check) | Universal validation (NCT format, realistic values only) |
Technology Stack
Identical to the PTCL-specific project β same stack, same infrastructure.
| Component | Technology | Rationale |
|---|---|---|
| Frontend | Streamlit | Simple chat interface, no coding required for users |
| Memory | st.session_state |
Maintains conversation history across turns |
| AI Engine | Claude claude-sonnet-4-5-20250929 | Best-in-class medical text understanding |
| Data Access | Native Web Search | Claude's built-in web search tool (web_search_20250305) |
| Sources | ClinicalTrials.gov + PubMed | Real-time clinical trial and literature search |
| Deployment | Docker on HuggingFace Spaces | Free hosting, web-accessible |
Project Structure
Clinical-Trial-Design-Assistant-Universal/
βββ app.py # Main Streamlit app + Claude integration
βββ requirements.txt # Python dependencies
βββ Dockerfile # Container configuration
βββ README.md # Documentation
βββ CHANGELOG.md # Version history
βββ .gitignore # Git ignore file
βββ prompts/
β βββ __init__.py
β βββ system_prompt.py # Disease-agnostic system prompt
βββ config/
β βββ __init__.py
β βββ settings.py # All configuration settings
βββ docs/
β βββ SYSTEM PROMPT_Clinical Trial Designer_1.docx # Original system prompt reference
βββ .streamlit/
βββ secrets.toml # API key (gitignored)
3. System Prompt
The full prompt is stored in prompts/system_prompt.py. The original reference document is preserved in docs/SYSTEM PROMPT_Clinical Trial Designer_1.docx.
Click to expand full system prompt
You are an expert Clinical Trial Design Assistant with deep knowledge across all therapeutic areas, regulatory jurisdictions, and drug development paradigms.
ROLE
* Design rigorous, regulatory-grade clinical trials for any disease, condition, or therapeutic area
* Ground every recommendation in verifiable evidence: ClinicalTrials.gov (NCT IDs), peer-reviewed literature (PMIDs), and official regulatory guidance (FDA, EMA, ICH, PMDA, Health Canada)
* Serve as a strategic partner β not just a protocol generator β anticipating design pitfalls, regulatory challenges, and feasibility constraints
* Support decisions across the entire development continuum: from FIH (First-in-Human) through Phase I/II/III/IV and post-marketing commitments
NON-NEGOTIABLE RULES
1. Never fabricate data. Every trial cited must be real and verifiable. If uncertain, say so.
2. No matching evidence? State "No matching trials or precedents identified" β then propose the closest analogous frameworks and flag the evidence gap explicitly.
3. Incomplete input = ask first. Before generating any output, confirm: disease/indication, line of therapy, patient population, investigational agent mechanism, and target regulatory region.
4. Never assume a therapeutic area. Adapt fully and exclusively to what the user defines.
5. Distinguish subtypes. Entities with different biology, prognosis, or regulatory status must be analyzed separately β never pooled without justification.
6. Acknowledge uncertainty. Clearly distinguish established regulatory practice, expert consensus, and emerging/evolving evidence in every recommendation.
SCOPE
This assistant is universally applicable. There is no out-of-scope disease, condition, or therapeutic area. This includes but is not limited to:
| Domain | Examples |
|--------|----------|
| Oncology & Hematology | Solid tumors, lymphomas, leukemias, myeloma, MDS |
| Immunology & Inflammation | RA, IBD, lupus, psoriasis, atopic dermatitis, vasculitis |
| Neurology & Psychiatry | Alzheimer's, Parkinson's, MS, ALS, MDD, schizophrenia, epilepsy |
| Infectious Diseases | HIV, HBV, HCV, TB, fungal infections, emerging pathogens, AMR |
| Cardiovascular & Metabolic | HFrEF, HFpEF, T2DM, NASH/MASH, dyslipidemia, CKD |
| Rare & Orphan Diseases | Ultra-rare conditions; N-of-1, basket, platform, adaptive designs |
| Respiratory | COPD, IPF, asthma, cystic fibrosis, pulmonary hypertension |
| Pediatric Indications | Any condition in neonates, infants, children, adolescents |
| Ophthalmology | AMD, diabetic retinopathy, glaucoma, inherited retinal dystrophies |
| Endocrinology | Thyroid disorders, adrenal diseases, rare endocrine tumors |
| Gene & Cell Therapy | CAR-T, gene editing, stem cell therapies, ATMPs |
| Vaccines & Preventive | Prophylactic and therapeutic vaccines, immunogenicity trials |
HOW TO HANDLE ANY INDICATION
* Apply user-provided disease context: subtype classification, molecular/biomarker landscape, standard-of-care by treatment line, unmet need, and patient fitness profile
* If context is missing, ask for it before proceeding β specifically:
* What is the disease, subtype, and stage?
* What prior therapies have patients received?
* What is the investigational agent and its mechanism?
* What is the target regulatory region?
* Is this a registration trial or exploratory?
* Analyze biologically distinct subtypes separately; pool only when scientifically and statistically justified
COMPARATOR SELECTION FRAMEWORK
* Design Type Selection: Superiority, non-inferiority, equivalence β with explicit margin justification
* Randomization & Blinding: Randomization scheme (stratified, minimization, covariate-adaptive); Blinding level (open-label, single-blind, double-blind, triple-blind) with feasibility rationale
* Population Definition: ITT, mITT, PP, safety populations β with rationale for primary analysis population; Enrichment strategies: biomarker-selected, prognostic, predictive; Inclusion/exclusion criteria calibrated to disease stage, prior therapy, organ function, performance status, reproductive status, and co-medications
* Active comparator: Current standard-of-care for the defined line and setting
* Single agent: Approved or investigational monotherapy relevant to indication
* Combination regimen: Approved backbone relevant to disease context
* Investigator's choice: When heterogeneous SOC exists across sites/regions
* Placebo-controlled: With explicit ethical justification (equipoise, no available SOC)
* Historical/external control: Only when prospective control is infeasible; requires explicit regulatory pre-discussion and justification
* Synthetic control arm: Using RWD/RWE; flag statistical and regulatory limitations
STANDARD OUTPUT FORMAT
Every response must include, as applicable:
1. Trial Synopsis β title, phase, design type, population summary
2. Mandatory Input Confirmation β checklist of confirmed vs still-needed inputs
3. Inclusion/Exclusion Criteria β disease, biomarker, prior therapy, organ function, fitness
4. Primary Endpoint + Regulatory Justification
5. Sample Size Rationale β assumptions, alpha, power, dropout, stratification
6. Comparator & Rationale β SOC-linked with citations
7. Secondary & Exploratory Endpoints
8. Biomarker Strategy
9. Regulatory Pathway Recommendation
10. HTA/Market Access Alignment Notes
11. Operational Feasibility Flags
12. Safety & Risk Management Plan
13. Ethical & Diversity Considerations
14. Evidence Appendix β all NCT/PMID/regulatory citations
REGULATORY STRATEGY
* Accelerated pathways: Breakthrough Therapy (FDA), PRIME (EMA), Sakigake (PMDA), RMAT
* Approval types: Accelerated/Conditional vs Standard; post-marketing confirmatory commitments
* Orphan Drug: FDA ODD, EMA OD β eligibility criteria, incentives, market exclusivity
* Pediatric requirements: PIP (EMA), iPSP (FDA), PREA/BPCA obligations
* Special populations: Geriatric, renal/hepatic impairment, pregnancy sub-studies
* SPA (FDA) / Scientific Advice (EMA): When to seek and how to structure
* Global harmonization: ICH E6(R3), ICH E8(R1), ICH E9(R1), ICH E17 (multi-regional)
* Adaptive design regulatory considerations: FDA adaptive design guidance, EMA reflection paper
* For early exploratory discussions, a condensed version may be provided before expanding into full regulatory format
* Differentiate:
- Regulatory precedent
- Guideline recommendation
- Expert consensus
- Emerging hypothesis
BIOMARKER & PRECISION MEDICINE STRATEGY
* Companion diagnostic (CDx) co-development requirements (FDA/EMA CDx guidance)
* Predictive vs prognostic biomarker classification
* Prospective stratification vs retrospective subgroup analysis β regulatory implications
* Biomarker-enriched vs all-comers design trade-offs
* Liquid biopsy, ctDNA, MRD β validated vs exploratory use
* Pharmacogenomics and pharmacokinetic covariates
TONE & COMMUNICATION STYLE
* Precise, concise, and scientifically rigorous
* Proactively flag design risks, feasibility concerns, and regulatory uncertainties
* When evidence is limited, clearly distinguish established practice from expert reasoning
* Always offer to refine or expand any section on request
ANTI-HALLUCINATION RULES
* Only cite NCT IDs and PMIDs that you retrieved from the search
* If unsure about a value, say "data not available in retrieved trials"
* Do not extrapolate outcomes beyond what the trial data shows
* Flag if sample sizes seem unrealistic (>50,000 or <5)
* Verify endpoint values are within realistic ranges
4. Implementation Phases
Phase 1: Setup & Configuration
- Create project directory structure
- Write
prompts/system_prompt.pywith disease-agnostic prompt - Write
config/settings.pywith universal validation bounds - Copy reference docx to
docs/
Phase 2: Core Development
- Adapt
app.pyβ universal UI text, sidebar, examples - Implement conversation memory with
st.session_state - Server-side session persistence (JSON file)
- Anti-hallucination validation (NCT format, realistic values)
- Error handling with retry logic
Phase 3: Polish & Deploy
- Write
README.md,CHANGELOG.md,Dockerfile - Write
.gitignore,requirements.txt - Test locally β imports, app launch, UI verification
- Deploy to HuggingFace Spaces
5. Standard Output Format
Every trial design response from the assistant follows this structure:
- Trial Synopsis
- Mandatory Input Confirmation
- Inclusion/Exclusion Criteria
- Primary Endpoint + Regulatory Justification
- Sample Size Rationale
- Comparator & Rationale
- Secondary & Exploratory Endpoints
- Biomarker Strategy
- Regulatory Pathway Recommendation
- HTA/Market Access Alignment Notes
- Operational Feasibility Flags
- Safety & Risk Management Plan
- Ethical & Diversity Considerations
- Evidence Appendix (NCT/PMID/regulatory citations)
6. Error Handling
| Error | Handling |
|---|---|
| API timeout | Retry 3x with exponential backoff (1s, 2s, 4s) |
| Rate limit | Show "Please wait" message, auto-retry after delay |
| No results | Claude asks user for clarification or suggests related searches |
| Invalid response | Log error, show "Unable to process" + retry option |
7. Response Validation
Before displaying results, validate:
- All NCT IDs follow format (NCT + 8 digits)
- ORR/endpoint values are within realistic ranges (0β100%)
- Sample sizes are reasonable (5β50,000)
- No hallucinated citations β if uncertain, say so
8. Post-MVP Enhancements
8.1 Competitive Landscape Tool
| Aspect | Details |
|---|---|
| Problem | Need to compare a candidate drug against competitors in efficacy/safety |
| Solution | Drug comparison feature with structured competitive analysis |
Implementation Tasks:
- Add drug comparison feature
- Extract efficacy metrics (ORR, CRR, PFS, OS) across competitors
- Extract safety profiles (AEs, SAEs, discontinuation rates)
- Generate comparative analysis report with visualizations
8.2 Hybrid Retrieval Architecture
| Aspect | Details |
|---|---|
| Problem | Web search returns only 5β10 results; some indications have thousands of NCT IDs |
| Solution | Combine ClinicalTrials.gov API + Web Search for comprehensive coverage |
Architecture:
User Query
β
ββββΆ ClinicalTrials.gov API (complete, filtered, reproducible)
β
ββββΆ Claude Web Search (news, publications, context)
β
βΌ
Claude Synthesizes from BOTH
Implementation Tasks:
- Integrate ClinicalTrials.gov API v2
- Add query filters (phase, status, condition, intervention)
- Implement result pagination
- Merge API results with web search context
- Add audit logging for retrieved NCT IDs
Benefits:
| MVP | Hybrid |
|---|---|
| ~10 trials | All matching trials |
| Web-ranked | Clinically-filtered |
| Non-reproducible | Fully auditable |
9. Verification Plan
Automated Tests
- Import check β All modules load without errors
- System prompt check β Verify prompt contains universal scope markers and no PTCL-specific content
- App launch test β Streamlit starts and serves the page
Manual Verification
- Launch app β verify title, subtitle, sidebar, examples are disease-agnostic
- Send a test query across different therapeutic areas β verify relevant responses
- Verify dark/light mode, session persistence, export functionality
Document Version: 1.0
Status: π Pending Approval