
Shares of drugmaker Vanda Pharmaceuticals VNDA.O fall 12.65% to $7.46 premarket
Co says it received a letter from the U.S. FDA declining to approve the use of its sleep drug Hetlioz to treat jet lag
FDA noted trials used simulated time shifts, not real air travel - VNDA
Co says it disagrees with FDA decision and plans further talks with agency
Hetlioz is already approved for two rare sleep disorders
As of last close, stock down ~3% over the past year