Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Total Revenues	$ 227,547	$ 148,364	$ 0
Operating expenses:
Cost of goods sold	2,392	0	0
Research and development	146,936	175,611	171,488
Selling, general and administrative	199,615	65,854	33,097
Total operating expenses	348,943	241,465	204,585
Loss from operations	(121,396)	(93,101)	(204,585)
Interest expense	(22,670)	(8,120)	(28)
Other income, net	515	4,056	2,803
Net loss	$ (143,551)	$ (97,165)	$ (201,810)
Net loss per common share - basic and diluted (in dollars per share)	$ (5.23)	$ (3.59)	$ (7.54)
Weighted-average shares outstanding (basic and diluted) (in shares)	27,473,873	27,090,284	26,754,308
Other comprehensive (loss) gain:
Unrealized (loss) gain on investments	$ (23)	$ 342	$ 526
Total comprehensive loss	(143,574)	(96,823)	(201,284)
Product
Revenues:
Total Revenues	12,965	0	0
Collaboration Revenue
Revenues:
Total Revenues	$ 214,582	$ 148,364	$ 0