Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues:
Net U.S. Auryxia product sales	$ 24,105	$ 14,116	$ 44,727	$ 24,621
License revenue	1,644	1,028	2,773	2,343
Total revenues	25,749	15,144	47,500	26,964
Costs and expenses:
Cost of goods sold	7,428	4,379	17,029	8,653
License expense	987	617	1,664	1,406
Research and development	8,774	9,012	17,162	15,776
Selling, general and administrative	28,711	24,986	54,548	48,089
Total costs and expenses	45,900	38,994	90,403	73,924
Operating loss	(20,151)	(23,850)	(42,903)	(46,960)
Other income (expense):
Amortization of debt discount	(1,316)	(62,965)	(1,316)	(62,965)
Other income (expense), net	(51)	338	171	452
Total other income (expense)	(1,367)	(62,627)	(1,145)	(62,513)
Loss before income taxes	(21,518)	(86,477)	(44,048)	(109,473)
Income tax (benefit) expense	0	20	(634)	40
Net loss	$ (21,518)	$ (86,497)	$ (43,414)	$ (109,513)
Basic and diluted net loss per common share (in dollars per share)	$ (0.18)	$ (0.77)	$ (0.36)	$ (1.00)
Weighted average shares used in computing basic and diluted net loss per common share (in shares)	120,451,534	112,590,188	120,149,604	109,846,152