CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net loss	$ (23,533)	$ (26,634)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	97	139
Non-cash lease expense	673	0
Stock based compensation expense	1,966	3,309
Amortization of debt issuance costs	8	25
Non-cash imputed interest expense related to the sale of future royalties	267	0
Non-cash interest income on investments	(51)	(131)
Non-cash interest expense on operating lease liability	50	0
Loss on extinguishment of debt	3,495	0
Loss on disposal of fixed assets	8	0
Changes in operating assets and liabilities:
Accounts receivable	(33)	218
Prepaid expenses, and other assets	(798)	(138)
Accounts payable and accrued and other liabilities	(2,006)	(1,913)
Operating lease liability	(749)	0
Total adjustments	2,927	1,509
Net cash used in operating activities	(20,606)	(25,125)
Cash flows from investing activities:
Purchase of investments	(10,914)	(26,145)
Sales and maturities of investments	4,950	42,950
Purchase of property and equipment	(41)	(85)
Net cash (used in) provided by investing activities	(6,005)	16,720
Cash flows from financing activities:
Proceeds from royalty interest purchase agreement with Oberland Capital Management, LLC	65,000	0
Payment of issuance costs on royalty interest purchase agreement	(584)	0
Proceeds from issuance of common stock under the Company's share-based compensation plan.	42	112
Payment of liability of future royalties, net of imputed interest	(1,139)	0
Payment on termination of credit agreement with HealthCare Royalty Partners, III, L.P.	(37,162)	0
Payments on Curis Royalty’s debt	(1,825)	(4,434)
Net cash provided by (used in) financing activities	24,332	(4,322)
Net decrease in cash and cash equivalents	(2,279)	(12,727)
Cash and cash equivalents, beginning of period	23,636	38,288
Cash and cash equivalents, end of period	$ 21,357	$ 25,561