Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenues:
Product, net	$ 35,011,000		$ 51,353,000
Total revenues	35,011,000		51,353,000
Costs and expenses:
Cost of sales	534,000		786,000
Research and development	58,908,000	$ 44,348,000	88,027,000	$ 83,174,000
Selling, general and administrative	36,069,000	17,752,000	62,285,000	38,628,000
EXONDYS 51 litigation and license charges	2,839,000		2,839,000
Total cost and expenses	98,350,000	62,100,000	153,937,000	121,802,000
Operating loss	(63,339,000)	(62,100,000)	(102,584,000)	(121,802,000)
Other income (loss):
Gain from sale of Priority Review Voucher			125,000,000
Interest income (expense) and other, net	184,000	(201,000)	519,000	(269,000)
Total other income (loss)	184,000	(201,000)	125,519,000	(269,000)
(Loss) income before income tax (benefit) expense	(63,155,000)	(62,301,000)	22,935,000	(122,071,000)
Income tax (benefit) expense	(109,000)	0	1,891,000	0
Net (loss) income	(63,046,000)	(62,301,000)	21,044,000	(122,071,000)
Other comprehensive income:
Unrealized gain on short-term securities - available-for-sale	17,000	6,000	82,000	112,000
Total other comprehensive income	17,000	6,000	82,000	112,000
Comprehensive (loss) income	$ (63,029,000)	$ (62,295,000)	$ 21,126,000	$ (121,959,000)
Net income (loss) per share:
Basic (loss) earnings per share	$ (1.15)	$ (1.35)	$ 0.38	$ (2.66)
Diluted (loss) earnings per share	$ (1.15)	$ (1.35)	$ 0.37	$ (2.66)
Weighted average number of shares of common stock used in calculating:
Basic (loss) earnings per share	54,976	46,157	54,913	45,927
Diluted (loss) earnings per share	54,976	46,157	56,176	45,927