CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 86,745	$ 91,032
Short-term investments	85,064	95,452
Prepaid expenses and other current assets	14,683	8,202
Total current assets	186,492	194,686
Property and equipment, net	2,666	1,936
Long-term investments	0	2,114
Right-of-use assets, net	14,519	2,274
Other assets	1,305	552
Total assets	204,982	201,562
Current liabilities:
Accounts payable	2,587	5,626
Accrued compensation and benefits	5,939	5,672
Current portion of operating lease liability	3,184	2,117
Loan payable, current portion	36,111	4,167
Deferred revenue	1,412	4,177
Accrued expenses and other current liabilities	8,552	6,657
Total current liabilities	57,785	28,416
Operating lease liability, net of current portion	11,548	413
Loan payable, net of current portion	15,133	46,621
Deferred revenue, non-current	2,947	0
Total liabilities	87,413	75,450
Commitments and contingencies (Note 11)
Stockholders’ equity:
Preferred stock, $0.0001 par value; 5,000,000 shares authorized; no shares issued and outstanding as of June 30, 2021 and December 31, 2020, respectively.	0	0
Common stock, $0.0001 par value; 300,000,000 shares authorized; 102,967,017 and 93,599,975 shares issued and outstanding as of June 30, 2021 and December 31, 2020, respectively.	10	9
Additional paid-in capital	750,664	680,872
Accumulated deficit	(633,109)	(554,765)
Accumulated other comprehensive income (loss)	4	(4)
Total stockholders’ equity	117,569	126,112
Total liabilities and stockholders’ equity	$ 204,982	$ 201,562