Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

Income Tax Disclosure [Abstract]

Schedule of Reconciliation of the Federal Statutory Income Tax Rate and the Company's Effective Income Tax Rate

A reconciliation of the federal statutory income tax rate and the Company’s effective income tax rate is as follows:

	Year Ended December 31,
	2019			2018			2017
Federal statutory income tax rate		(21.0	)%		(21.0	)%		(34.0	)%
State income taxes		(8.9	)		(8.6	)		(6.9	)
Research and development tax credits		(5.1	)		(4.7	)		(3.4	)
Stock-based compensation		1.2			(0.6	)		3.6
Change in U.S. tax rate		-			-			18.7
Change in valuation allowance		33.8			34.9			22.0
Effective income tax rate		-	%		-	%		-	%

Summary of Company's Net Deferred Tax Assets (Liabilities)

The Company’s net deferred tax assets (liabilities) consisted of the following:

	December 31,
	2019			2018
	(in thousands)
Deferred tax assets:
Intangibles, including acquired in-process    research and development	$	1,091		$	1,201
Capitalized start-up costs		421			463
Net operating loss carryforwards		63,245			34,234
Research and development credit carryforwards		19,417			11,766
Operating lease liability		5,008			-
Deferred revenue		7,843			12,199
Equity-based compensation		7,092			4,064
Accruals and allowances		1,245			1,359
Gross deferred tax assets		105,362			65,286
Deferred tax asset valuation allowance		(98,513	)		(64,046	)
Total deferred tax assets		6,849			1,240
Deferred tax liabilities:
Fixed assets		(1,633	)		(1,240	)
Operating lease right-of-use assets		(5,216	)		-
Total deferred tax liabilities		(6,849	)		(1,240	)
Net deferred tax asset (liability)	$	-		$	-