Exhibit 5.1 828,571 SHARES HALOZYME THERAPEUTICS, INC. SHARES OF COMMON STOCK ($0.001 PAR VALUE) PLACEMENT AGENT AGREEMENTHalozyme Therapeutics Inc • December 14th, 2005 • Biological products, (no disgnostic substances) • New York
Company FiledDecember 14th, 2005 Industry Jurisdiction