support

**TREM2/Microglial Druggability Assessment:**

**Chemical Matter & Programs:**
- **AL002** (Alector): TREM2 agonist antibody - Phase 2 trials
- **Sargramostim** (GM-CSF): Microglial activation - completed Phase 2
- **Anti-CD33 antibodies**: Multiple programs (discontinued due to toxicity)

**Competitive Landscape:**
- **Alector** (NASDAQ: ALEC): Leading TREM2 programs
- **Denali Therapeutics**: Transport vehicle technology
- **Genentech/Roche**: Anti-Tau programs with microglial components

**Current Status:**
- AL002 in Phase 2 for AD (results pending)
- Multiple microglial imaging studies ongoing
- Population-specific approaches **completely unexplored**

## PRACTICAL FEASIBILITY RANKING:

### **1. MOST FEASIBLE: Mitochondrial Rescue (Hypothesis 6)**
- **Rationale**: Established drug classes, some population-specific evidence exists
- **Immediate path**: Stratify existing NAD+/antioxidant trials by mitochondrial haplogroup
- **Investment needed**: $15-25M for proof-of-concept study
- **Timeline**: 3-5 years to population-stratified Phase 2

### **2. MODERATE FEASIBILITY: TREM2 Modulation (Hypothesis 5)**
- **Rationale**: Hot clinical area, but zero population data
- **Immediate path**: Add population genetics to existing TREM2 trials
- **Investment needed**: $30-50M for new population-stratified trial
- **Timeline**: 5-7 years for dedicated population study

### **3. LOWEST FEASIBILITY: All Others**
- **Major barriers**: Safety concerns (estrogen), lack of chemical matter (autophagy), or insufficient mechanistic foundation

## RECOMMENDED DEVELOPMENT STRATEGY:

**Phase 1 (Years 1-2): $5-10M**
- Large-scale genomic study of mitochondrial haplogroups in SEA-AD cohorts
- Validate haplogroup-specific mitochondrial dysfunction markers
- Screen existing mitochondrial compounds in haplogroup-stratified cell models

**Phase 2 (Years 3-5): $15-25M**  
- Population-stratified trial of lead mitochondrial compound
- Partner with existing Asian AD cohorts/biobanks
- Primary endpoint: population-specific biomarker responses

**Success Criteria:**
- >30% difference in treatment response between haplogroups
- Regulatory pathway discussion with FDA/PMDA for population-specific indication

**Key Risk**: All hypotheses fundamentally lack the foundational population genetics data needed for therapeutic development. Consider this a high-risk research program rather than near-term therapeutic opportunity.