CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 58,064	$ 378,021
Short-term marketable securities	222,767	127,255
Accounts receivable, net of allowances of $0 at December 31, 2019 and 2018, respectively		620
Receivables from collaborative arrangements	11,996	10,053
Receivables from licensing arrangements	10,000
Amounts due from TRC, LLC	28,574	5,422
Other prepaid and current assets	7,087	11,452
Total current assets	338,488	532,823
Property and equipment, net	12,644	13,176
Long-term marketable securities	4,985	11,869
Operating lease assets	46,604
Tax receivable	3,682
Restricted cash	833	833
Other assets	1,590	1,534
Total assets	408,826	560,235
Current liabilities:
Accounts payable	4,758	9,028
Accrued personnel-related expenses	28,180	23,803
Accrued clinical and development expenses	17,587	11,876
Accrued interest payable	5,659	3,086
Non-recourse notes due 2033, net	9,851
Operating lease liabilities	7,762
Deferred revenue	31,575	43,402
Other accrued liabilities	6,331	7,359
Total current liabilities	111,703	98,554
Convertible senior notes due 2023, net	225,890	224,818
Non-recourse notes due 2033, net	219,300	229,535
Deferred rent		7,976
Long-term operating lease liabilities	47,725
Long-term deferred revenue	6,761	26,179
Other long-term liabilities	21,287	24,762
Commitments and contingencies (Notes 11 and 13)
Shareholders' Deficit
Preferred shares, $0.00001 par value: 230 shares authorized, no shares issued or outstanding
Ordinary shares, $0.00001 par value: 200,000 shares authorized; 57,015 and 55,681 shares issued and outstanding at December 31, 2019 and 2018, respectively	1	1
Additional paid-in capital	1,024,614	960,721
Accumulated other comprehensive income (loss)	145	(166)
Accumulated deficit	(1,248,600)	(1,012,145)
Total shareholders' deficit	(223,840)	(51,589)
Total liabilities and shareholders' deficit	$ 408,826	$ 560,235