Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (20,428)	$ (16,731)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation for property, plant and equipment	307	276
Loss on disposal of property, plant and equipment	65
Amortization of intangible assets	674	763
Reduction in the carrying amount of the right-of-use assets	687	627
Gain on disposal of intangible assets	0	(450)
Impairment of intangible assets		1,537
Stock-based compensation expense	3,038	3,892
Acquired in-process research and development	6,555	1,081
Change in fair value of investments	(3,482)	(309)
Impairment loss of long-term investment	865
Changes in operating assets and liabilities:
Accounts receivable	(1,122)	(1,311)
Inventories	(2,119)	4,112
Prepaid expenses and other assets	352	(33)
Accounts payable	884	(3,277)
Accrued liabilities and other liabilities	(1,592)	(1,190)
Deferred income	(25)	(11)
Net cash used in operating activities	(15,341)	(11,024)
CASH FLOWS FROM INVESTING ACTIVITIES
Proceeds from disposal of intangible assets		450
Purchases of property, plant and equipment	(1,208)	(103)
Loan to a related party		(4,265)
Cash paid to acquire in-process research and development	(6,250)	(1,081)
Receipt of government grants related to land use right		2,264
Net cash used in investing activities	(13,044)	(2,735)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from notes payable		466
Proceeds from bank borrowings	709
Stock issuance costs	(2,019)	(42)
Proceeds from sale of common stock	32,500	1,399
Proceeds from exercise of stock options		3,852
Repurchase of stock options to satisfy tax withholding obligations		(251)
Net cash provided by financing activities	31,190	5,424
Effect of exchange rate change on cash and cash equivalents	488	(398)
Net increase in cash and cash equivalents	3,293	(8,733)
Cash and cash equivalents at beginning of period	57,064	53,621
Cash and cash equivalents at end of period	60,357	44,888
Supplemental disclosure of cash flow information:
Interest paid	0	0
Income taxes paid	0	$ 0
Non-cash investing activity:
Accrual for acquisition of in-process research and development	305
Black Belt Tx Limited
CASH FLOWS FROM INVESTING ACTIVITIES
Cash paid to acquire convertible loan	(86)
Cleave Therapeutics, Inc
CASH FLOWS FROM INVESTING ACTIVITIES
Cash paid to acquire convertible loan	$ (5,500)