Consolidated Statements of Cash Flows $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Operating activities
Net loss	$ (39,421)	$ (116,508)
Adjustments to reconcile net loss to net cash used for operating activities:
Share-based compensation expense	6,207	23,733
Depreciation expense	2,188	4,552
Non-cash interest expense	6,379	8,775
Inventory fair value step-up adjustment included in cost of product sales	2,458
Amortization of intangible assets	647
Change in fair value of contingent value rights	(800)
Amortization of right-of-use lease assets	1,249	1,307
Loss on short-term investments	502
Loss on disposal of property and equipment, net of gain on lease termination	10	24
Changes in operating assets and liabilities:
Accounts receivable, net	(1,687)	(1,579)
Inventory, net	(1,493)	(191)
Prepaid expenses and other current assets	2,297	644
Accounts payable	(2,815)	(4,395)
Accrued expenses	(5,781)	395
Accrued payroll and related expenses	(5,454)	823
Lease liabilities	(2,126)	(2,530)
Net cash used for operating activities	(37,640)	(84,950)
Investing activities
Acquisition of Tetraphase, net of cash, cash equivalents and restricted cash acquired	(33,513)
Purchases of short-term investments	(2,999)
Purchases of property and equipment		(698)
Proceeds from the sale of property and equipment	3,070
Proceeds from the sale of short-term investments	2,497
Net cash used for investing activities	(30,945)	(698)
Financing activities
Net proceeds from issuance of common stock under 2013 Equity Plan	605	31
Net proceeds from issuance of common stock under ESPP	512	833
Net cash provided by financing activities	1,117	864
Net decrease in cash, cash equivalents and restricted cash	(67,468)	(84,784)
Cash, cash equivalents and restricted cash, beginning of period	88,729	173,513
Cash, cash equivalents and restricted cash, end of period	21,261	88,729
Supplemental disclosure of non-cash investing and financing activities
Initial recognition of right-of-use lease asset	536	16,798
Conversion of Series F Convertible Preferred Stock into common stock		2,737
Cumulative-effect adjustment from adoption of ASU 2018-07		(160)
Reconciliation of cash, cash equivalents and restricted cash to the consolidated balance sheets
Cash and cash equivalents	21,221	87,820
Restricted cash	40	909
Cash, cash equivalents and restricted cash, end of period	$ 21,261	$ 88,729