Condensed Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 78,527	$ 10,206
Short‑term investments	77,310	49,295
Accounts receivable	234	786
Prepaid expenses and other current assets	3,587	3,574
Total current assets	159,658	63,861
Long‑term investments	20,713	2,978
Property and equipment, net	25	28
Other long‑term assets	83	0
Total assets	180,479	66,867
Current liabilities:
Accounts payable	3,501	2,462
Accrued expenses and other current liabilities	3,174	3,559
Deferred revenue, current	1,796	1,796
Total current liabilities	8,471	7,817
Deferred revenue, long‑term	6,286	6,735
Other non‑current liabilities	20	22
Total liabilities	14,777	14,574
Commitments and contingencies (see Note 7)
Stockholders’ deficit:
Preferred stock: $0.0001 par value; 20,000,000 shares and no shares authorized at March 31, 2018 and December 2017, respectively; no shares issued and outstanding at March 31, 2018 and December 31, 2017	0	0
Common stock: $0.0001 par value; 300,000,000 shares and 55,000,000 shares authorized at March 31, 2018 and December 31, 2017, respectively; 22,977,998 and 5,298,593 shares issued and outstanding at March 31, 2018 and December 31, 2017, respectively	3	1
Additional paid‑in capital	237,749	2,207
Accumulated other comprehensive loss	(202)	(51)
Accumulated deficit	(71,848)	(59,191)
Total stockholders’ deficit	165,702	(57,034)
Total liabilities, convertible preferred stock and stockholders’ deficit	180,479	66,867
Series A Convertible Preferred Stock
Current liabilities:
Convertible preferred stock	0	14,183
Series B Convertible Preferred Stock
Current liabilities:
Convertible preferred stock	0	44,820
Series C Convertible Preferred Stock
Current liabilities:
Convertible preferred stock	$ 0	$ 50,324