Collaborations (Tables)

3 Months Ended

Mar. 31, 2021

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Change in Accounts Receivable, Contract Asset and Liabilities

The following table presents the changes in accounts receivable, contract assets and liabilities for the three months ended March 31, 2021 (in thousands):

	Balance at December 31, 2020		Additions		Deductions			Balance at March 31, 2021
Accounts receivable and contract assets:
Billed receivables - Sanofi	$	577	$	856	$	(577	)	$	856
Unbilled receivables - Sanofi		856		878		(856	)		878
Total accounts receivable and contract assets	$	1,433	$	1,734	$	(1,433	)	$	1,734
Contract liabilities:
Deferred revenue - Vertex	$	37,748	$	—	$	(7,138	)	$	30,610
Deferred revenue - Sanofi		132,642		878		(11,564	)		121,956
Total contract liabilities	$	170,390	$	878	$	(18,702	)	$	152,566