 NEW YORK--BUSINESS WIRE--Halper Sadeh LLP, a global investor rights law firm, is investigating whether the sale of Five Prime Therapeutics, Inc. NASDAQ: FPRX to Amgen Inc. for 38.00 per share in cash is fair to Five Prime shareholders. Halper Sadeh encourages Five Prime shareholders to click here to learn more about their legal rights and options or contact Daniel Sadeh or Zachary Halper at 212 763-0060 or or The investigation concerns wheth 