Collaboration Agreements (Tables)

9 Months Ended

Sep. 30, 2019

Collaboration agreements

Schedule of changes in the balances of our contract assets and liabilities and recognized revenue

The following table presents changes in the balances of our contract assets and liabilities during the nine months ended September 30, 2019 and 2018:

	Balance at
	Beginning						Balance at
	of Period		Additions		Deductions		End of Period
Nine months ended September 30, 2019
Contract assets	$	—	$	—	$	—	$	—
Contract liabilities:
Deferred revenue	$	46,196	$	—	$	41,550	$	4,646
	Balance at
	Beginning						Balance at
	of Period		Additions		Deductions		End of Period
Nine months ended September 30, 2018
Contract assets	$	—	$	—	$	—	$	—
Contract liabilities:
Deferred revenue	$	52,439	$	2,373	$	7,906	$	46,906

During the three months ended September 30, 2019 and 2018 and the nine months ended September 30, 2019 and 2018, the Company recognized the following revenues as a result of changes in the contract asset and the contract liability balances in the respective periods:

	Three months ended				Nine months ended
	September 30,				September 30,
	2019		2018		2019		2018
Revenue recognized in the period from:
Amounts included in the contract liability at the beginning of the period	$	834	$	1,760	$	41,550	$	7,515
Performance obligations satisfied in previous periods	$	—	$	—	$	—	$	—