---
title: "EFFICACY BIOTECH MASTER FUND LTD. — Ownership Dossier"
canonical: https://whiteintel.dev/entity/3d7b4357-dcf2-5c48-b79b-6973788d6c08
json: https://whiteintel.dev/api/public/dossier/3d7b4357-dcf2-5c48-b79b-6973788d6c08
identifier: sec:0001366070
jurisdiction: US
risk: Low
source: WhiteIntel corporate-ownership graph
---

# EFFICACY BIOTECH MASTER FUND LTD.

**Type:** Company  
**Jurisdiction:** US  
**Identifier:** `sec:0001366070`  
**Risk level:** Low  
**Canonical dossier:** https://whiteintel.dev/entity/3d7b4357-dcf2-5c48-b79b-6973788d6c08  
**Structured JSON / MCP:** https://whiteintel.dev/api/public/dossier/3d7b4357-dcf2-5c48-b79b-6973788d6c08  

## Ownership & control

### Holdings / subsidiaries

- **AEOLUS PHARMACEUTICALS, INC.** (tenpercentowner) — https://whiteintel.dev/entity/519998d9-2ce7-59e5-b7ac-34784ff68e61
- **REPROS THERAPEUTICS INC** (tenpercentowner) — https://whiteintel.dev/entity/ef95e20f-545a-5660-8655-f28f01c3dab0

---

_This is the markdown-for-agents view of the WhiteIntel dossier for **EFFICACY BIOTECH MASTER FUND LTD.**. Human view: https://whiteintel.dev/entity/3d7b4357-dcf2-5c48-b79b-6973788d6c08 · Structured JSON: https://whiteintel.dev/api/public/dossier/3d7b4357-dcf2-5c48-b79b-6973788d6c08._

_Risk levels are heuristic investigative leads, not legal determinations of beneficial ownership. Every claim carries a source; an absent edge means "not yet observed in current sources", not "does not exist"._