Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating activities:
Net income (loss)	$ 36,316	$ (117,391)
Reconciliation of net income (loss) to net cash used in operating activities:
Depreciation and amortization	3,293	2,574
Equity-based compensation	32,200	21,960
Loss from equity method investment	5,467	3,256
Expense related to ViaCyte transaction		15,109
Other income, non-cash		(169)
Changes in:
Accounts receivable	49	2,074
Prepaid expenses and other assets	(25,342)	(2,502)
Accounts payable and accrued expenses	420	7,982
Deferred revenue	1,714	(270)
Deferred rent		(528)
Operating lease assets and liabilities	(689)
Other liabilities, net	(127)	38
Net cash provided by (used in) operating activities	53,301	(67,867)
Investing activities:
Purchase of property and equipment	(5,732)	(1,773)
Net cash used in investing activities	(5,732)	(1,773)
Financing activities:
Proceeds from issuance of common shares, net of issuance costs	121,216	309,019
Proceeds from exercise of options	5,049	8,241
Repurchase of treasury shares		(57)
Net cash provided by financing activities	126,265	317,203
Effect of exchange rate changes on cash	(14)	(15)
Increase in cash	173,820	247,548
Cash, cash equivalents and restricted cash, beginning of period	459,812	242,912
Cash, cash equivalents and restricted cash, end of period	633,632	490,460
Supplemental disclosure of non-cash investing and financing activities
Property and equipment purchases in accounts payable and accrued expenses	428
Equity issuance costs in accounts payable and accrued expenses	$ 739	$ 1,980