Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Reconciliation of Cash, Cash Equivalents, and Restricted Cash

The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported in the consolidated balance sheet that sum to the total of the amounts reported in the consolidated statement of cash flows (in thousands):

	December 31, 2021		December 31, 2020		December 31, 2019
Cash and cash equivalents	$	149,800	$	228,698	$	147,449
Prepaid expenses and other current assets	—		395		263
Other assets	2,039		2,039		2,092
Total cash, cash equivalents, and restricted cash shown    in the statement of cash flows	$	151,839	$	231,132	$	149,804

Revenue and Gross Accounts Receivable By Major Customer

Gross revenues and accounts receivable from each of the Company’s Customers or collaboration partners who individually accounted for 10% or more of total gross revenues and/or 10% or more of total gross accounts receivable consisted of the following:

	Percent of Total Gross Revenues
	Years Ended December 31,
	2021		2020		2019
Fresenius Medical Care Rx	33	%	29	%	21	%
AmerisourceBergen Drug Corporation	16	%	12	%	10	%
Otsuka Pharmaceutical Co. Ltd.	14	%	29	%	45	%
McKesson Corporation	13	%	11	%	—	%
Cardinal Health, Inc.	11	%	—	%	—	%

	Percent of Gross Accounts Receivable
	As of December 31,
	2021		2020
Otsuka Pharmaceutical Co. Ltd.	22	%	—	%
MTPC	20	%	—	%
Fresenius Medical Care Rx	16	%	19	%
AmerisourceBergen Drug Corporation	15	%	29	%
Cardinal Health, Inc.	10	%	14	%
McKesson Corporation	—	%	12	%

Summary of Property and Equipment and Related Accumulated Depreciation

The following is the summary of property and equipment and related accumulated depreciation as of December 31, 2021 and 2020.

	Useful Life			December 31, 2021		December 31, 2020
				(in thousands)
Computer equipment and software	3			$	1,010	$	1,010
Furniture and fixtures	5	-	7	2,086		2,086
Equipment	7			2,750		2,692
Leasehold improvements	Shorter of the useful life or remaining lease term			8,573		8,573
				14,419		14,361
Less accumulated depreciation				(7,665)		(5,739)
Net property and equipment				$	6,754	$	8,622