Statements of Comprehensive Loss - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating expenses:
General and administrative	$ 2,087,000	$ 2,223,000
Research and development	4,977,000	5,280,000
Total operating expenses	7,064,000	7,503,000
Loss from operations	(7,064,000)	(7,503,000)
Interest (expense) income	(160,000)	12,000
Other expense		(5,000)
Loss before income taxes	(7,224,000)	(7,496,000)
Provision (benefit) for income taxes	0	0
Net loss	(7,224,000)	(7,496,000)
Comprehensive loss	$ (7,224,000)	$ (7,496,000)
Net loss per share:
Basic and diluted (Note 9)	$ (0.58)	$ (0.79)
Number of shares used in per share calculations:
Basic and diluted	12,439,591	9,521,224