Condensed Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities
Net loss	$ (26,817)	$ (24,201)
Adjustments to reconcile net loss to net cash, cash equivalents, and restricted cash used in operating activities
Depreciation and amortization	2,174	2,080
Amortization of convertible notes debt discount	4,389
Stock‑based compensation expense	155	125
Change in fair value of warrant liability	31
Change in contingent consideration	957	3,188
Accrued interest on notes payable and convertible notes payable	1,025	415
Amortization of debt issuance costs	109	109
Provision for doubtful accounts	113
Write off of assets		16
Changes in operating assets and liabilities, net of assets acquired and liabilities assumed in acquisitions:
Accounts receivable	(217)	17
Other current assets	(4,283)	14
Other long-term assets	(5)	10
Accounts payable and other accrued liabilities	5,369	1,722
Deferred revenue	4,390	508
Net cash and cash equivalents and restricted cash used in operating activities	(12,610)	(15,997)
Cash flows from investing activities
Purchase of property and equipment	(1,483)	(915)
Patent costs and intangible asset acquisition, net	(151)	(79)
Payments to acquire Oncimmune	(750)
Net cash and cash equivalents and restricted cash used in investing activities	(2,384)	(994)
Cash flows from financing activities
Proceeds from issuance of series H preferred stock		10,000
Proceeds from issuance of convertible notes payable	12,955	10,000
Proceeds from exercise of common stock options	25	45
Proceeds from Paycheck protection program note payable	3,085
Other	(10)	(14)
Net cash and cash equivalents and restricted cash provided by financing activities	16,055	20,031
Net increase in cash and cash equivalents and restricted cash	1,061	3,040
Cash, cash equivalents, and restricted cash ‑ beginning of period	5,469	6,094
Cash, cash equivalents, and restricted cash ‑ end of period	6,530	$ 9,134
Supplemental disclosure of non cash activity
Value of put option recorded at issuance of convertible notes payable	$ 3,389