CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 104,735	$ 58,064
Short-term marketable securities	333,605	222,767
Receivables from collaborative arrangements	11,413	11,996
Receivables from licensing arrangements		10,000
Amounts due from TRC, LLC	35,509	28,574
Other prepaid and current assets	13,124	7,087
Total current assets	498,386	338,488
Property and equipment, net	14,433	12,644
Long-term marketable securities		4,985
Operating lease assets	45,184	46,604
Tax receivable	3,986	3,682
Restricted cash	833	833
Other assets	1,508	1,590
Total assets	564,330	408,826
Current liabilities:
Accounts payable	10,065	4,758
Accrued personnel-related expenses	26,757	28,180
Accrued clinical and development expenses	25,229	17,587
Accrued interest payable	3,702	5,659
Non-recourse notes due 2033, net		9,851
Operating lease liabilities	8,741	7,762
Deferred revenue	25,062	31,575
Other accrued liabilities	7,018	6,331
Total current liabilities	106,574	111,703
Convertible senior notes due 2023, net	226,427	225,890
Non-recourse notes due 2035, net	375,266
Non-recourse notes due 2033, net		219,300
Long-term operating lease liabilities	47,631	47,725
Long-term deferred revenue	1,154	6,761
Other long-term liabilities	9,614	21,287
Commitments and contingencies
Shareholders' Deficit
Preferred shares, $0.00001 par value: 230 shares authorized, no shares issued or outstanding	0	0
Ordinary shares, $0.00001 par value: 200,000 shares authorized; 63,515 and 57,015 shares issued and outstanding at June 30, 2020 and December 31, 2019, respectively	1	1
Additional paid-in capital	1,191,923	1,024,614
Accumulated other comprehensive income	280	145
Accumulated deficit	(1,394,540)	(1,248,600)
Total shareholders' deficit	(202,336)	(223,840)
Total liabilities and shareholders' deficit	$ 564,330	$ 408,826