Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 35,247	$ 9,808
Prepaid expenses and other current assets	293	311
Total current assets	35,540	10,119
Property and equipment, net	284	237
Operating lease right-of-use asset	2,963	3,182
Restricted cash	329	329
Deferred offering costs	1,650	1,096
Total assets	40,766	14,963
Current liabilities:
Accounts payable	1,358	1,069
Accrued expenses and other current liabilities	2,881	3,240
Operating lease liability	919	899
Total current liabilities	5,158	5,208
Operating lease liability, net of current portion	2,192	2,427
Total liabilities	7,350	7,635
Commitments and contingencies (Note 11)
Total redeemable convertible preferred stock	160,197	130,666
Stockholders’ deficit:
Additional paid-in capital	5,208	4,419
Accumulated deficit	(131,989)	(127,757)
Total stockholders’ deficit	(126,781)	(123,338)
Total liabilities, redeemable convertible preferred stock and stockholders’ deficit	40,766	14,963
Series A-1 Redeemable Convertible Preferred Stock
Current liabilities:
Total redeemable convertible preferred stock	39,742	39,742
Series A-2 Redeemable Convertible Preferred Stock
Current liabilities:
Total redeemable convertible preferred stock	18,393	18,393
Series A-3 Redeemable Convertible Preferred Stock
Current liabilities:
Total redeemable convertible preferred stock	38,114	38,114
Series A-4 Redeemable Convertible Preferred Stock
Current liabilities:
Total redeemable convertible preferred stock	6,000	6,000
Series B Redeemable Convertible Preferred Stock
Current liabilities:
Total redeemable convertible preferred stock	28,496	$ 28,417
Series C Redeemable Convertible Preferred Stock
Current liabilities:
Total redeemable convertible preferred stock	$ 29,452