Condensed Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
CURRENT ASSETS:
Cash and cash equivalents	$ 13,065	$ 18,748
Prepaid expenses and other current assets	4,080	1,498
Investments	19,889
Total current assets	37,034	20,246
Other assets	230
TOTAL ASSETS	37,264	20,246
CURRENT LIABILITIES:
Accounts payable	1,688	3,015
Accrued expenses and other current liabilities	4,829	1,413
Total current liabilities	6,517	4,428
Total liabilities	6,517	4,428
Convertible preferred stock		35,410
STOCKHOLDERS’ EQUITY (DEFICIT):
Common stock, $0.0001 par value; 100,000,000 and 20,441,982 shares authorized as of September 30, 2019 and December 31, 2018, respectively; 17,134,190 shares and 5,513,531 shares issued and outstanding as of September 30, 2019 and December 31, 2018, respectively	1
Additional paid-in capital	79,872	1,665
Accumulated other comprehensive loss	11
Accumulated deficit	(49,137)	(21,257)
Total stockholders' equity (deficit)	30,747	(19,592)
TOTAL LIABILITIES, CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ EQUITY (DEFICIT)	$ 37,264	20,246
Series A Convertible Preferred Stock
CURRENT LIABILITIES:
Convertible preferred stock		6,254
Series B Convertible Preferred Stock
CURRENT LIABILITIES:
Convertible preferred stock		$ 29,156