CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 49,542	$ 34,236
Short-term investments	202,519	113,846
Prepaid expenses and other current assets	6,628	2,589
Total current assets	258,689	150,671
Property, plant and equipment, net	1,120	840
Restricted cash	401	225
Total assets	260,210	151,736
Current liabilities:
Accounts payable	7,640	2,427
Deferred rent		83
Accrued expenses and other current liabilities	5,942	4,210
Total current liabilities	13,582	6,720
Long-term liabilities:
Deferred rent	372	228
Total liabilities	13,954	6,948
Commitments and contingencies
Stockholders’ equity:
Common stock, $0.001 par value: 120,000,000 shares authorized; 34,410,725 and 27,284,140 shares issued and outstanding December 31, 2018 and December 31, 2017, respectively	34	27
Additional paid-in capital	430,824	255,013
Accumulated deficit	(184,602)	(110,252)
Total stockholders’ equity	246,256	144,788
Total liabilities, convertible preferred stock and stockholders’ equity	$ 260,210	$ 151,736

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).