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SKILL.md
Drug Research Strategy
Comprehensive drug investigation using 50+ ToolUniverse tools across chemical databases, clinical trials, adverse events, pharmacogenomics, and literature.
KEY PRINCIPLES:
Report-first approach - Create report file FIRST, then populate progressively
Compound disambiguation FIRST - Resolve identifiers before research
Citation requirements - Every fact must have inline source attribution
Evidence grading - Grade claims by evidence strength
Mandatory completeness - All sections must exist, even if "data unavailable"
English-first queries - Always use English drug/compound names in tool calls, even if the user writes in another language. Only try original-language terms as a fallback. Respond in the user's language
Critical Workflow Requirements
1. Report-First Approach (MANDATORY)
DO NOT show the search process or tool outputs to the user. Instead:
Create the report file FIRST - Before any data collection, create a markdown file:
Then progressively replace [Researching...] with actual findings as you query each tool.
FDA Label Core Fields Bundle
For approved drugs, ALWAYS retrieve these FDA label sections early (after getting set_id from DailyMed_search_spls):
Critical Label Sections
Call DailyMed_get_spl_sections_by_setid(setid=set_id, sections=[...]) with these sections:
Phase 1 (Mechanism & Chemistry):
mechanism_of_action → Section 3.1
pharmacodynamics → Section 3.1
chemistry → Section 2.4
Phase 2 (ADMET & PK):
clinical_pharmacology → Section 4
pharmacokinetics → Section 4.1-4.4
drug_interactions → Section 4.3, 6.5
Phase 3 (Safety & Dosing):
warnings_and_cautions → Section 6.3
adverse_reactions → Section 6.1
dosage_and_administration → Section 6.6, 8.2
Phase 4 (PGx & Clinical):
pharmacogenomics → Section 7
clinical_studies → Section 5.5
description → Section 2.5 (formulation)
inactive_ingredients → Section 2.5
Label Extraction Strategy
1. Get set_id: DailyMed_search_spls(drug_name)
2. Batch call for all core sections (or 3-4 calls with 4-5 sections each):
DailyMed_get_spl_sections_by_setid(setid=set_id, sections=["mechanism_of_action", "pharmacodynamics", ...])
3. Extract and populate report sections as you retrieve data
This ensures you have authoritative FDA-approved information even if prediction tools fail.
Compound Disambiguation (Phase 1)
CRITICAL: Establish compound identity before any research.
Objective: Comprehensive regulatory and intellectual property landscape
Multi-Step Chain:
1. DailyMed_search_spls(drug_name=drug_name)
└─ Extract: SetID for regulatory label data
2. FDA_OrangeBook_search_drug(brand_name=drug_name)
└─ Extract: Application number, approval dates [★★★]
3. FDA_OrangeBook_get_approval_history(appl_no=app_number)
└─ Extract: Original approval date, supplements, label changes [★★★]
4. FDA_OrangeBook_get_exclusivity(brand_name=drug_name)
└─ Extract: Exclusivity types (NCE, Pediatric, Orphan), expiration dates [★★★]
5. FDA_OrangeBook_get_patent_info(brand_name=drug_name)
└─ Extract: Patent numbers, substance/formulation claims [★★★]
6. FDA_OrangeBook_check_generic_availability(brand_name=drug_name)
└─ Extract: Generic entries, TE codes (AB rating), first generic date [★★★]
7. DailyMed_get_spl_sections_by_setid(setid=set_id, sections=["indications_and_usage"])
└─ Parse for: breakthrough designation, priority review, orphan status [★★★]
8. DailyMed_get_spl_by_setid(setid=set_id)
└─ Extract special populations sections (Section 8.5):
└─ pediatric_use (LOINC 34076-0): age groups, dosing, safety
└─ geriatric_use (LOINC 34082-8): efficacy, safety in elderly
└─ pregnancy (LOINC 42228-7): risk summary, animal data, recommendations
└─ nursing_mothers (LOINC 34080-2): lactation risk, recommendations
└─ Extract: renal/hepatic dosing from dosage section [★★★]
9. Parse DailyMed SPL revision history for regulatory timeline (Section 8.6):
└─ Initial approval date
└─ Major label changes (safety updates, indication expansions)
└─ PMR/PMC commitments from label [★★★]
10. Combine FDA_OrangeBook_get_approval_history + label data:
└─ Create regulatory timeline table
└─ Document approval pathway (priority, breakthrough, orphan)
└─ Note limitation: US-only data [★★★]
CRITICAL:
Orange Book data is US-only; document limitation for EMA/PMDA
Patent expiration dates may not be directly available; calculate from approval + exclusivity periods
Document workaround: "Exact patent dates require Orange Book file download"
Special populations require XML parsing from full SPL (DailyMed_get_spl_by_setid)
Look for LOINC section codes to reliably extract special population data
Output for Section 8.3:
### 8.3 Patents & Exclusivity
#### US Regulatory Status
**Application Number**: NDA 213869
**Original Approval**: May 12, 2023
**Approval Pathway**:
- Priority Review ✓
- Breakthrough Therapy Designation ✓
- Orphan Drug Status ✓
*Source: FDA Orange Book via `FDA_OrangeBook_get_approval_history`*
#### Exclusivity Periods
| Type | Code | Expiration Date | Protections |
|------|------|-----------------|-------------|
| New Chemical Entity (NCE) | N | May 2028 | Blocks ANDA filing for 5 years |
| Orphan Drug | O | May 2030 | Market exclusivity for indication |
| Pediatric | P | November 2030 | +6 months extension |
*Source: `FDA_OrangeBook_get_exclusivity`*
**Estimated Patent Cliff**: ~2030 (based on NCE + Orphan + Pediatric exclusivity)
#### Patent Information
| Patent Number | Substance/Formulation | Use Code | Expiration |
|---------------|----------------------|----------|------------|
| 10,689,356 | Substance | U-1 | 2037 |
| 11,123,456 | Crystal form | U-2 | 2039 |
*Source: `FDA_OrangeBook_get_patent_info`*
**Note**: Exact patent expiration dates require FDA Orange Book download; dates shown are estimates.
#### Generic Availability
**Generic Approved**: No
**First Generic Date**: Not applicable
**ANDA Applications**: None approved
*Source: `FDA_OrangeBook_check_generic_availability`*
**Market Protection Summary**: Drug is protected by NCE exclusivity until 2028, orphan exclusivity until 2030, and substance patents until 2037+. No generic competition expected before 2030.
**Limitation**: EMA and PMDA approval/patent data not available via public API.
### 8.5 Special Populations
#### Pediatric Use
**Age Groups Studied**: Not established in pediatric patients
**Dosing**: No pediatric dosing recommendations available
**Safety**: Safety and efficacy not established in patients <18 years
*Source: DailyMed SPL pediatric_use section (LOINC 34076-0)*
#### Geriatric Use (≥65 years)
**Population**: 20% of clinical trial participants were ≥65 years
**Efficacy**: No overall differences in efficacy observed
**Safety**: Similar adverse event profile to younger adults
**Dosing**: No dose adjustment required
*Source: DailyMed SPL geriatric_use section (LOINC 34082-8)*
#### Pregnancy (Category D / Pregnancy Class)
**Risk Summary**: Based on animal studies and mechanism of action, may cause fetal harm. Advise pregnant women of potential risk to fetus.
**Animal Data**:
- Rats: Fetal toxicity observed at exposures ≥0.03× human dose
- Rabbits: Embryo-fetal toxicity at ≥0.01× human dose
**Human Data**: No adequate and well-controlled studies in pregnant women
**Recommendation**: Verify pregnancy status prior to initiation. Advise use of effective contraception during treatment and for 1 week after final dose.
*Source: DailyMed SPL pregnancy section (LOINC 42228-7)*
#### Lactation
**Risk Summary**: No data on presence in human milk, effects on breastfed infant, or milk production
**Recommendation**: Advise women not to breastfeed during treatment and for 1 week after final dose due to potential for serious adverse reactions in breastfed infants.
*Source: DailyMed SPL nursing_mothers section (LOINC 34080-2)*
#### Renal Impairment
| eGFR (mL/min/1.73m²) | Dosing Recommendation |
|----------------------|----------------------|
| ≥30 (mild-moderate) | No dose adjustment required |
| <30 (severe) | Not studied; use with caution |
| ESRD on dialysis | Not recommended |
#### Hepatic Impairment
| Child-Pugh Class | Dosing Recommendation |
|------------------|----------------------|
| A (mild) | No dose adjustment required |
| B (moderate) | Reduce dose to 258 mg once daily |
| C (severe) | Not recommended |
*Source: DailyMed SPL dosage_and_administration section*
### 8.6 Regulatory Timeline & History
#### US FDA Timeline
| Date | Milestone | Notes |
|------|-----------|-------|
| 2018-03 | IND filed | Phase 1 initiated |
| 2019-11 | Breakthrough Therapy Designation | For ER+/HER2- mBC with ESR1 mutation |
| 2020-02 | Phase 3 (EMERALD) initiated | vs fulvestrant |
| 2022-08 | NDA submitted | Priority Review granted |
| 2023-01-27 | FDA approval | Accelerated approval pathway |
**Application Number**: NDA 213869
**Review Classification**: Priority Review (6-month timeline)
**Approval Pathway**: Accelerated approval under Subpart H
**Designation**: Breakthrough Therapy, Orphan Drug
*Source: FDA Orange Book + DailyMed label history*
#### Post-Marketing Requirements (PMRs)
| PMR | Description | Due Date | Status |
|-----|-------------|----------|--------|
| PMR 1 | Confirmatory Phase 3 trial (EMERALD) | 2025-12 | Completed |
| PMR 2 | Pediatric assessment | 2028-06 | Ongoing |
#### Major Label Changes
| Date | Change Type | Summary |
|------|-------------|---------|
| 2023-01-27 | Initial approval | ER+/HER2- mBC, ESR1 mutation |
| 2023-06-15 | Safety update | Added hepatotoxicity monitoring |
| 2024-02-01 | Indication expansion | Added post-CDK4/6i language |
*Source: DailyMed SPL revision history*
**Regulatory Pathway Summary**: Received Breakthrough Therapy Designation (2019), Priority Review, and Accelerated Approval (2023). Confirmatory trial (EMERALD) successfully completed in 2025, converting to full approval.
**Limitation**: EMA and PMDA approval data not available via public API. US data only.
PATH 8: Real-World Evidence
Objective: Complement clinical trial efficacy with real-world effectiveness data
Multi-Step Chain:
1. search_clinical_trials(study_type="OBSERVATIONAL", intervention=drug_name, pageSize=50)
└─ Extract: RWE studies, registry trials, observational cohorts [★★★]
2. PubMed_search_articles(query=f"{drug_name} (real-world OR observational OR effectiveness)", max_results=20)
└─ Extract: RWE publications, adherence studies, off-label use [★★☆]
3. PubMed_search_articles(query=f"{drug_name} (registry OR post-marketing OR surveillance)", max_results=10)
└─ Extract: Post-marketing surveillance, long-term outcomes [★★☆]
4. Compare efficacy vs effectiveness:
└─ Clinical trial primary outcomes vs real-world outcomes
└─ Trial inclusion criteria vs real-world patient demographics
└─ Adherence rates in trials vs clinical practice
Output for Section 9.4:
### 9.4 Real-World Evidence
#### Observational Studies
**Registry Trials**: 12 ongoing, 8 completed
**Key Studies**:
- **ELEVATE Registry** (NCT04857528): Real-world safety/effectiveness in 500+ ER+ breast cancer patients
- **Post-Marketing Surveillance**: European Drug Monitoring (PASS required through 2027)
*Source: ClinicalTrials.gov via `search_clinical_trials` (study_type="OBSERVATIONAL")*
#### Real-World Effectiveness
| Outcome | Clinical Trial (Pivotal) | Real-World Study | Difference |
|---------|-------------------------|------------------|------------|
| PFS (months) | 3.8 (EMERALD, N=478) | 3.2 (ELEVATE, N=312) | -0.6 mo |
| Response rate | 19.2% | 16.5% | -2.7% |
| Treatment duration | 5.4 mo | 4.1 mo | -1.3 mo |
**Effectiveness Gap Analysis**: Real-world PFS ~16% shorter than trial efficacy, likely due to:
- Broader patient population (less restrictive than trial inclusion)
- Higher discontinuation rates (AE intolerance, cost issues)
- Sequential therapy effects (more prior lines than trial allowed)
*Sources: PMID:34567890 (ELEVATE interim), PMID:35678901 (comparative effectiveness)*
#### Adherence & Persistence
**Mean Treatment Duration**: 4.1 months (RWE) vs 5.4 months (trial)
**Discontinuation Reasons** (RWE cohort, N=312):
- Progression: 58%
- Adverse events: 28%
- Patient preference/cost: 9%
- Death: 5%
**Adherence Rate**: 73% (defined as MPR ≥0.8) in community oncology setting
*Source: PMID:36789012 (US claims database analysis)*
#### Off-Label Use
**Documented Off-Label Indications**:
- ER+ metastatic breast cancer, no prior endocrine therapy: 12% of prescriptions
- Male breast cancer: 3% of prescriptions
- Early breast cancer (neoadjuvant): < 1% (investigational)
*Source: PubMed literature review*
**RWE Insights**: Real-world data shows slightly lower effectiveness than pivotal trials but confirms benefit in broader patient population. Adherence challenges highlight need for AE management strategies.
PATH 9: Comparative Analysis
Objective: Position drug within therapeutic class with head-to-head and indirect comparisons
Multi-Step Chain:
1. Identify comparator drugs:
└─ User provides OR infer from indication + mechanism
└─ Example: For elacestrant (ER degrader), comparators = fulvestrant, other SERDs
2. For each comparator, run abbreviated tool chain:
a. PubChem_get_CID_by_compound_name(compound=comparator)
b. ChEMBL_search_activities(chemblid=comparator_chemblid, target="ESR1", max_results=20)
└─ Extract: Potency vs primary target
c. search_clinical_trials(intervention=comparator, condition=indication, pageSize=20)
└─ Extract: Phase 3 trial counts, approval status
d. FAERS_count_reactions_by_drug_event(medicinalproduct=comparator)
└─ Extract: Top 5 adverse events, seriousness ratio
3. Search for head-to-head trials:
search_clinical_trials(intervention=f"{drug_name} AND {comparator}")
└─ Extract: Direct comparison trials [★★★]
4. PubMed_search_articles(query=f"{drug_name} vs {comparator}", max_results=10)
└─ Extract: Network meta-analyses, indirect comparisons [★★☆]
5. Create comparison tables across dimensions:
└─ Potency, selectivity, ADMET, efficacy, safety, cost (if available)
Output for Section 10.5:
### 10.5 Comparative Analysis
#### Drug Class: Selective Estrogen Receptor Degraders (SERDs)
**Primary Comparators**: Fulvestrant (approved), AZD9833 (investigational), GDC-9545 (investigational)
#### Potency Comparison
| Drug | ESR1 WT IC50 | ESR1 Y537S IC50 | Selectivity | Source |
|------|-------------|-----------------|-------------|--------|
| **Elacestrant** | 48 nM | 77 nM | > 100x vs other NRs | ChEMBL |
| Fulvestrant | 9 nM | ~50 nM (est) | > 100x | ChEMBL |
| AZD9833 | 0.7 nM | 1.2 nM | > 1000x | Literature |
**Potency Ranking**: AZD9833 > Fulvestrant ≈ Elacestrant for WT; all active against Y537S
*Sources: ChEMBL via `ChEMBL_search_activities`, PMID:33445678*
#### Clinical Trial Landscape
| Drug | Phase 3 Trials | Primary Indication | Approval Status |
|------|----------------|-------------------|-----------------|
| Elacestrant | 2 completed, 1 ongoing | ER+/HER2- mBC | Approved (US, 2023) |
| Fulvestrant | 15+ completed | ER+/HER2- mBC | Approved (2002) |
| AZD9833 | 3 ongoing | ER+/HER2- mBC | Investigational |
| GDC-9545 | 2 ongoing | ER+/HER2- mBC | Investigational |
*Source: ClinicalTrials.gov*
#### Safety Profile Comparison
| Drug | Top AE (% patients) | Serious AE Rate | Fatal Outcomes |
|------|---------------------|-----------------|----------------|
| Elacestrant | Nausea (35%), Fatigue (30%) | 51.8% | 4.7% (FAERS) |
| Fulvestrant | Injection site reaction (40%), Hot flash (28%) | 48.2% | 3.9% (FAERS) |
**Safety Differentiation**: Elacestrant oral administration avoids injection site reactions but has higher GI AE rate.
*Sources: FAERS via `FAERS_count_reactions_by_drug_event`, product labels*
#### Head-to-Head Trials
**EMERALD vs Fulvestrant**:
- Trial: NCT03778931 (Phase 3, N=478, completed)
- PFS: 3.8 mo (elacestrant) vs 1.9 mo (fulvestrant) in ESR1-mutated subgroup (HR 0.55, p<0.001)
- PFS: 2.2 mo vs 1.9 mo in overall population (HR 0.84, p=0.05)
*Source: `extract_clinical_trial_outcomes` (NCT03778931)*
#### Differentiation Factors
| Factor | Elacestrant Advantage | Fulvestrant Advantage |
|--------|----------------------|----------------------|
| **Route** | Oral (QD) | IM injection (Q4W after loading) |
| **ESR1 mutant efficacy** | +100% PFS improvement | Less data |
| **Brain metastases** | BBB penetration (preclinical) | Poor CNS penetration |
| **Approval** | Biomarker-selected (ESR1 mut) | Broader indication |
| **Experience** | Limited (1 yr post-approval) | Extensive (20+ yrs) |
**Positioning**: Elacestrant fills unmet need for oral SERD with superior efficacy in ESR1-mutated disease. Fulvestrant remains standard for ESR1 WT due to longer track record.
Type Normalization & Error Prevention
Common Validation Errors
Many ToolUniverse tools require string inputs but may return integers or floats. Always convert IDs to strings.
Problem Examples:
ChEMBL target IDs: 12345 (int) → should be "12345" (str)
PubMed IDs: 23456789 (int) → should be "23456789" (str)
Clinical trial NCT IDs: sometimes parsed as numbers
Type Normalization Helper
Before calling any tool with ID parameters:
# Convert all IDs to strings
chembl_ids = [str(id) for id in chembl_ids]
nct_ids = [str(id) for id in nct_ids]
pmids = [str(id) for id in pmids]
Include evidence quality summary for each major section:
### 5. Clinical Development
**Evidence Quality**: Strong (156 Phase 3 trials, 203 Phase 2, 67 Phase 1)
**Data Confidence**: High - mature clinical program with decades of data
Section Completeness Checklist
Before finalizing any report, verify each section meets minimum requirements:
Section 1 (Identity) - Minimum Requirements
PubChem CID with link
ChEMBL ID with link (or "Not in ChEMBL")
Canonical SMILES
Molecular formula and weight
At least 3 brand names OR "Generic only"
Salt forms identified (or "Parent compound only")
Section 2 (Chemistry) - Minimum Requirements
6+ physicochemical properties in table format (including pKa if available)
Lipinski rule assessment with pass/fail
QED score with interpretation
Solubility data (predicted or label-based)
Salt forms documented (or "Parent compound only")
2D structure image embedded (PubChem link)
Formulation details if available (dosage forms, excipients)
Section 3 (Mechanism) - Minimum Requirements
FDA label MOA text quoted (if approved drug) OR literature MOA summary
Primary mechanism described in 2-3 sentences
At least 1 primary target with UniProt ID
Activity type and potency (IC50/EC50/Ki) with assay count
Target selectivity table (including mutant forms if relevant, e.g., ESR1 Y537S for endocrine drugs)