Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2020

Accounting Policies [Abstract]

Schedule of Restricted Cash

Restricted Cash—

(in thousands)	As of December 31, 2020		As of December 31, 2019
Letter of credit security: Cambridge lease	$	264	$	264
Letter of credit security: Waltham lease	250		250
Letter of credit security: Vienna Austria lease	336		94
Letter of credit security: Boston lease	1,144		1,144
Corporate credit card collateral	—		150
Total restricted cash	$	1,994	$	1,902
Restricted cash included in prepaid expenses and other current assets	$	264	$	—
Restricted cash included in other assets	$	1,730	$	1,902

Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash to Cash Flows

The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the consolidated balance sheets to the sum to the total of amounts shown in the Company’s consolidated statements of cash flows as of December 31, 2020, 2019 and 2018:

(in thousands)	December 31, 2020		December 31, 2019		December 31, 2018		December 31, 2017
Cash and cash equivalents	$	78,708	$	126,184	$	8,134	$	26,684
Restricted cash, current (included within prepaid expenses and other current assets)	264		—		—		—
Restricted cash, non-current (included within other assets)	1,730		1,902		364		364
Total cash, cash equivalents and restricted cash	$	80,702	$	128,086	$	8,498	$	27,048

Property and Equipment Useful Life

Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization expense is recognized using the straight-line method over the estimated useful life of each asset, as follows:

	Estimated Useful Life
Office furniture	3 to 7 years
Computer equipment	3 years
Laboratory equipment	3 to 10 years
Leasehold improvements	Shorter of lease term or 10 years