CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net loss	$ (9,709)	$ (9,884)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	25	35
Non-cash lease expense	149	240
Stock-based compensation expense	625	651
Amortization of debt issuance costs	0	8
Non-cash imputed interest expense related to the sale of future royalties	235	131
Non-cash interest expense on investments	25	4
Loss on extinguishment of debt	0	3,495
Loss on disposal of fixed assets	0	5
Changes in operating assets and liabilities:
Accounts receivable	737	1,078
Prepaid expenses, and other assets	(248)	146
Accounts payable and accrued and other liabilities	(689)	(2,895)
Operating lease liability	(166)	(247)
Total adjustments	693	2,651
Net cash used in operating activities	(9,016)	(7,233)
Cash flows from investing activities:
Sales and maturities of investments	5,082	600
Purchase of property and equipment	(241)	0
Net cash provided by investing activities	4,841	600
Cash flows from financing activities:
Sale of common stock	3,000	0
Proceeds from royalty interest purchase agreement with Oberland Capital Management, LLC	0	65,000
Payment of issuance costs on royalty interest purchase agreement	0	(250)
Payment of liability of future royalties, net of imputed interest	(1,723)	0
Payment on termination of credit agreement with HealthCare Royalty Partners, III, L.P.	0	(37,162)
Payments on Curis Royalty’s debt	0	(1,825)
Net cash provided by financing activities	1,277	25,763
Net decrease in cash and cash equivalents and restricted cash	(2,898)	19,130
Cash and cash equivalents and restricted cash, beginning of period	16,399	23,789
Cash and cash equivalents and restricted cash, end of period	13,501	42,919
Accrued issuance costs	274	334
Property and equipment purchases in accounts payable	26	0
Cash paid for interest	1,062	948
Non-cash commitment shares issued to Aspire Capital	$ 900	$ 0