Shares of Voyager Therapeutics Inc. and its partner, Neurocrine Biosciences Inc., fell in early trading Dec. 23 after Voyager announced an FDA clinical hold on the phase II Restore-1 trial of VY-AADC, an adeno-associated virus-based gene therapy Neurocrine is developing as NBIb-1817 for the treatment of Parkinson's disease. The trial had been paused since at least November as its data safety monitoring board reviewed MRI abnormalities in some study participants.