CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 93,282	$ 58,064
Short-term marketable securities	265,065	222,767
Receivables from collaborative arrangements	12,399	11,996
Receivables from licensing arrangements		10,000
Amounts due from TRC, LLC	48,909	28,574
Prepaid clinical and development services	20,761	2,736
Other prepaid and current assets	10,308	4,351
Total current assets	450,724	338,488
Property and equipment, net	15,430	12,644
Long-term marketable securities		4,985
Operating lease assets	44,391	46,604
Tax receivable		3,682
Restricted cash	833	833
Other assets	810	1,590
Total assets	512,188	408,826
Current liabilities:
Accounts payable	6,442	4,758
Accrued personnel-related expenses	30,472	28,180
Accrued clinical and development expenses	26,944	17,587
Accrued interest payable	5,791	5,659
Non-recourse notes due 2033, net		9,851
Operating lease liabilities	9,685	7,762
Deferred revenue	18,204	31,575
Other accrued liabilities	6,732	6,331
Total current liabilities	104,270	111,703
Convertible senior notes due 2023, net	226,695	225,890
Non-recourse notes due 2035, net	384,482
Non-recourse notes due 2033, net		219,300
Long-term operating lease liabilities	47,823	47,725
Long-term deferred revenue	750	6,761
Other long-term liabilities	9,704	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; 63,956 and 57,015 shares issued and outstanding at September 30, 2020 and December 31, 2019, respectively	1	1
Additional paid-in capital	1,206,524	1,024,614
Accumulated other comprehensive income	122	145
Accumulated deficit	(1,468,183)	(1,248,600)
Total shareholders' deficit	(261,536)	(223,840)
Total liabilities and shareholders' deficit	$ 512,188	$ 408,826