Consolidated Statements of Operations - USD ($) shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue
Net product sales	$ 10,056,000	$ 0	$ 0
Contract revenue - related party	0	0	616,000
Total revenue	10,056,000	0	616,000
Operating expenses
Cost of product sales	1,643,000	0	0
Research and development	117,302,000	84,575,000	62,288,000
Selling, general and administrative	85,162,000	30,852,000	16,700,000
Total operating expenses	204,107,000	115,427,000	78,988,000
Loss from operations	(194,051,000)	(115,427,000)	(78,372,000)
Interest expense	(7,303,000)	0	0
Interest income	1,885,000	624,000	187,000
Interest income	(5,418,000)	624,000	187,000
Net loss	$ (199,469,000)	$ (114,803,000)	$ (78,185,000)
Basic and diluted net loss per share (usd per share)	$ (7.85)	$ (5.41)	$ (4.54)
Weighted-average common shares outstanding - basic and diluted (in shares)	25,422	21,215	17,228