v3.23.2
Income Taxes (Tables)
 12 Months Ended
Dec. 31, 2022
Income Tax Disclosure [Abstract]  
Effective Income Tax Rate Differs From Statutory Federal Income Tax Rate Our effective income tax rate differs from the statutory federal income tax rate as follows for the years ended December 31, 2022, 2021 and 2020:
 Year ended December 31,
 202220212020
Federal tax at statutory rate21.0 %21.0 %21.0 %
State and local tax at statutory rate2.5 3.0 3.1 
Research and development tax credits— — 0.1 
Change in valuation allowance(19.3)(22.7)(21.5)
Other permanent differences(1.0)(1.0)(0.4)
Stock option cancellations(2.5)— — 
Stock option shortfalls(1.6)— — 
Effect of rate changes0.6 0.3 0.7 
Provision to return adjustment0.3 0.3 (1.5)
Prior period adjustment to State NOL DTA— — (1.5)
Other— (0.9)— 
Effective tax rate— %— %— %
Significant Components of Deferred Tax Assets and Liabilities Significant components of the Company’s deferred tax assets and liabilities are as follows (in thousands):
 December 31,
 20222021
Deferred tax assets:  
Accrued expenses and other current liabilities$2,924 $3,306 
Deferred revenue1,250 9,725 
Sale of royalty13,291 12,037 
Stock-based compensation 8,317 9,194 
Research and development credits4,827 5,034 
Capitalized research and development costs13,825 — 
Other non-current liabilities2,754 20,424 
Net operating loss carryforward288,842 287,194 
ASC 842 lease liability8,032 9,096 
Inventories reserve17,411 10,281 
Refund liability9,478 — 
Other13,159 10,483 
Total deferred tax assets384,110 376,774 
Less: valuation allowance(360,621)(342,408)
Total deferred tax assets, net of valuation allowance23,489 34,366 
Deferred tax liabilities:
Intangible asset(15,981)(25,598)
ASC 842 ROU asset(7,426)(8,486)
Other(82)(282)
Total deferred tax liabilities(23,489)(34,366)
Net deferred tax liability$— $— 
Unrecognized Tax Benefits Roll Forward
A reconciliation of the beginning and ending amounts of unrecognized tax benefits for the years ending December 31, 2022 and 2021 are as follows (in thousands):

Balance at December 31, 2020$2,352 
Additions based on tax positions of current years161 
Balance at December 31, 2021$2,513 
Additions based on tax positions of current years184 
Balance at December 31, 2022$2,697