CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 314,265	$ 377,793
Accounts receivable and accrued income from related party	222	947
Prepaid expenses	4,082	4,718
Other current assets	1,066	748
Total current assets	319,635	384,206
Non-current assets
Property, plant and equipment, net of accumulated depreciation of $31.3 million as of June 30, 2020 and $28.6 million as of December 31, 2019 respectively	29,301	28,771
Operating lease right-of-use assets	26,139	26,797
Intangible assets, net	7,087	5,427
Goodwill	496	496
Restricted cash	2,683	2,933
Total non-current assets	65,706	64,424
Total assets	385,341	448,630
Current liabilities
Accounts payable	4,942	5,681
Accrued expenses and other current liabilities	13,250	12,457
Current portion of operating lease liabilities	5,495	5,865
Current portion of deferred revenue	6,153	7,627
Total current liabilities	29,840	31,630
Non-current liabilities
Long-term debt	35,373	36,062
Operating lease liabilities, net of current portion	30,279	31,133
Deferred revenue, net of current portion	23,048	23,138
Derivative financial instruments related party	832	3,075
Other non-current liabilities	464	534
Total non-current liabilities	89,996	93,942
Total liabilities	119,836	125,572
Commitments and contingencies
Shareholders' equity
Ordinary shares, 0.05 par value: 60,000,000 shares authorized at June 30, 2020 and December 31, 2019 and 44,444,405 and 43,711,954 ordinary shares issued and outstanding at June 30, 2020 and December 31, 2019, respectively.	2,692	2,651
Additional paid-in-capital	1,000,389	986,803
Accumulated other comprehensive loss	(7,319)	(6,689)
Accumulated deficit	(730,257)	(659,707)
Total shareholders' equity	265,505	323,058
Total liabilities and shareholders' equity	$ 385,341	$ 448,630