Drug developer Bind Therapeutics said it ended a partnership with Amgen Inc. to develop targeted cancer therapy due to unsatisfactory results.

Bind's shares fell 15 percent to $10.95 in extended trading on Wednesday. Amgen's shares were little changed from their close of $121.03.

"Despite achieving the objective of high tumor concentrations, the results were not sufficiently compelling to proceed forward and both collaborators have agreed that the program will not be continued," Bind's Chief Executive Scott Minick said in a statement.

The company had entered into a twelve-month collaboration agreement with Amgen in January 2013 to develop cancer treatments using Bind's nanotechnology platform and an Amgen compound.