Original: The X-37's aerodynamic design was derived from the Space Shuttle, hence the X-37 has a similar lift-to-drag ratio, and a lower cross range at high altitudes and Mach numbers than DARPA's Hypersonic Technology Vehicle.
Simplified: The X-37's aerodynamic design was derived from the Space Shuttle, hence the X-37 has a similar lift-to-drag ratio, and a lower cross range at high altitudes and mach numbers than the Hypersonic Technology Vehicle.