Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
CURRENT ASSETS
Cash and cash equivalents	$ 19,253	$ 22,461
Marketable securities	52,696	52,052
Prepaid expenses and other current assets	2,556	2,158
Total current assets	74,505	76,671
Restricted cash	1,500
Property and equipment, net	2,385	1,018
Operating lease right-of-use assets	4,726
Other non-current assets	67	50
TOTAL ASSETS	83,183	77,739
CURRENT LIABILITIES
Accounts payable	3,154	663
Operating lease liabilities	351
Accrued and other current liabilities	14,854	9,576
Total current liabilities	18,359	10,239
Non-current operating lease liabilities	4,712
Other non-current liabilities	31	72
TOTAL LIABILITIES	23,102	10,311
Commitments and Contingencies (Note 14)
STOCKHOLDERS’ EQUITY
Preferred stock, $0.0001 par value; 10,000,000 shares authorized as of December 31, 2019 and 2018; no shares issued and outstanding as of December 31, 2019 and 2018
Common stock, $0.0001 par value; 500,000,000 shares authorized as of December 31, 2019 and 2018, 29,084,437 shares and 24,140,097 shares issued and outstanding as of December 31, 2019 and 2018, respectively	3	2
Additional paid-in capital	255,142	184,314
Accumulated other comprehensive income (loss)	51	(27)
Accumulated deficit	(195,115)	(116,861)
TOTAL STOCKHOLDERS’ EQUITY	60,081	67,428
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 83,183	$ 77,739