Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 33,099	$ 68,454
Marketable securities	221,865	445,733
Prepaid expenses	9,108	6,718
Acquisition holdback amount placed in escrow	25,000	0
Other current assets	3,202	11,825
Total current assets	292,274	532,730
Property and equipment, net	9,782	2,870
Operating lease right-of-use assets	8,134
Intangible assets	102,500	102,500
Goodwill	6,234	6,234
Other noncurrent assets	1,442	3,997
Total assets	420,366	648,331
Current liabilities:
Accounts payable	7,553	7,989
Accrued and other current liabilities	23,125	18,086
Acquisition holdback liability	24,444	0
Deferred revenue, noncurrent	5,688	0
Current portion of operating lease liabilities	1,431
Current portion of contingent consideration	35,200	32,300
Total current liabilities	97,441	58,375
Deferred revenue, noncurrent	8,113	0
Operating lease liabilities, net of current portion	11,095
Contingent consideration, net of current portion	35,700	45,900
Deferred income taxes	17,425	17,425
Other long-term liabilities	0	3,830
Total liabilities	169,774	125,530
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value; 10,000 shares authorized; none issued and outstanding	0	0
Common stock, $0.001 par value; 100,000 and 50,000 shares authorized and 44,251 and 42,078 shares issued and outstanding at September 30, 2019 and December 31, 2018, respectively	44	42
Additional paid-in capital	1,309,523	1,218,710
Accumulated deficit	(1,059,397)	(695,954)
Accumulated other comprehensive income	422	3
Total stockholders’ equity	250,592	522,801
Total liabilities and stockholders’ equity	$ 420,366	$ 648,331