Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
CURRENT ASSETS:
Cash and cash equivalents	$ 228,628	$ 220,198
Restricted cash	389	440
Prepaid expenses and other current assets	36,076	40,658
Total current assets	265,093	261,296
NON-CURRENT ASSETS:
Operating lease right-of-use assets	3,179	4,306
Deferred tax assets	4,022	3,336
Long-term prepaid expenses and other assets	6,239	7,049
Total assets	278,533	275,987
CURRENT LIABILITIES:
Accounts payable	8,195	5,892
Accrued expenses and other liabilities	11,447	11,301
Operating lease liabilities - current	2,385	2,411
Total current liabilities	22,027	19,604
NON-CURRENT LIABILITIES
Long-term debt	29,434	28,757
Operating lease liabilities - non-current	799	1,882
Total liabilities	52,260	50,243
Commitments and contingencies (Note 8)
SHAREHOLDERS' EQUITY:
Ordinary shares, £0.008 par value; 68,387,469 and 61,943,471 shares authorized, issued and outstanding at June 30, 2024 and December 31, 2023, respectively	699	635
Additional paid-in capital	695,353	621,645
Accumulated other comprehensive loss	(16,881)	(16,926)
Accumulated deficit	(452,898)	(379,610)
Total shareholders' equity	226,273	225,744
Total liabilities and shareholders' equity	$ 278,533	$ 275,987