Collaborative arrangements (Tables)

12 Months Ended

Dec. 31, 2019

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Summary of Total Transaction Price, Allocation of Total Transaction Price to Identified Performance Obligations Under Arrangement and Amount of Transaction Price Unsatisfied

The following tables summarize the total transaction price, the allocation of the total transaction price to the identified performance obligations under the arrangement, and the amount of the transaction price unsatisfied as of December 31, 2019 (in thousands):

	Ide-cel transaction price as of December 31, 2019
Up-front non-refundable payment - BMS Collaboration Agreement	$	75,000
Up-front non-refundable payment - Amended BMS Collaboration Agreement	25,000
Ide-cel license fee - Ide-cel License Agreement	10,000
Ide-cel development milestone	10,000
Estimated variable consideration	87,189
	$	207,189

	Allocation of transaction price to performance obligations		Transaction price unsatisfied as of December 31, 2019
Ide-cel research and development services	$	40,912	$	—
Ide-cel license and manufacturing services	166,277		17,815
	$	207,189	$	17,815

The following table summarizes the net collaboration revenue recognized or expense incurred for the joint ide-cel development efforts in the U.S. under ASC 808, including revenue or expense related to the combined performance obligation for the license and vector manufacturing of ide-cel in the U.S. for the years ended December 31, 2019, 2018, and 2017 (in thousands):

	For the years ended December 31,
	2019		2018		2017 (2)
ASC 808 ide-cel revenue - U.S. (1)	$	—	$	6,255	$	4,905
ASC 808 ide-cel research and development expense - U.S. (1)	$	32,415	$	8,689	$	3,037

⁽¹⁾As noted above, the calculation of collaboration revenue or research and development expense to be recognized for joint ide-cel development efforts in the U.S. is performed on a quarterly basis. The calculation is independent of previous activity, which may result in fluctuations between revenue and expense recognition period over period, depending on the varying extent of effort performed by each party during the period.

⁽²⁾The Company adopted Topic 606 effective January 1, 2018 using the modified retrospective transition method.  Therefore, amounts disclosed in the table above pertaining to the year ended December 31, 2017 are presented under previous accounting guidance and are therefore not comparable to the amounts recorded in the current period under Topic 606.

Revenue related to the combined unit of accounting for the non-US license and vector manufacturing services is accounted for in accordance with Topic 606. The following table summarizes the revenue recognized related to the combined unit of accounting for the ide-cel non-US license and vector manufacturing services for the years ended December 31, 2019, 2018, and 2017 (in thousands):

	For the years ended December 31
	2019		2018		2017 (1)
ASC 606 ide-cel license and manufacturing revenue - outside of U.S.	$	25,522	$	35,900	$	10,372

⁽¹⁾The Company adopted Topic 606 effective January 1, 2018 using the modified retrospective transition method.  Therefore, amounts disclosed in the table above pertaining to the year ended December 31, 2017 are presented under previous accounting guidance and are therefore not comparable to the amounts recorded in the current period under Topic 606.

The following tables summarize the total transaction price, the allocation of the total transaction price to the identified performance obligations under the arrangement, and the amount of the transaction price unsatisfied as of December 31, 2019 (in thousands):

	bb21217 transaction price as of December 31, 2019
bb21217 license fee - bb21217 License Agreement	$	15,000
Estimated variable consideration	26,687
	$	41,687

	Allocation of transaction price to performance obligations		Transaction price unsatisfied as of December 31, 2019
bb21217 research and development services	$	5,444	$	—
bb21217 license and manufacturing services	36,243		36,243
	$	41,687	$	36,243

Summary of Revenue Recognized Related to Research and Development Services

The following table summarizes the revenue recognized, or revenue adjustment recorded, related to the ide-cel research and development services for the years ended December 31, 2019, 2018, and 2017 (in thousands):

	For the years ended December 31,
	2019		2018		2017 (1)
Ide-cel research and development services revenue	$	2,264	$	5,751	$	6,208
	$	2,264	$	5,751	$	6,208

⁽¹⁾The Company adopted Topic 606 effective January 1, 2018 using the modified retrospective transition method.  Therefore, amounts disclosed in the table above pertaining to the year ended December 31, 2017 are presented under previous accounting guidance and are therefore not comparable to the amounts recorded in the current period under Topic 606.

The following table summarizes the revenue recognized related to the bb21217 research and development services for the years ended December 31, 2019, 2018, and 2017 (in thousands):

	For the years ended December 31,
	2019		2018		2017 (1)
bb21217 research and development services revenue	$	2,163	$	2,884	$	721
	$	2,163	$	2,884	$	721

⁽¹⁾The Company adopted Topic 606 effective January 1, 2018 using the modified retrospective transition method.  Therefore, amounts disclosed in the table above pertaining to the year ended December 31, 2017 are presented under previous accounting guidance and are therefore not comparable to the amounts recorded in the current period under Topic 606.

Changes in Balances of Company's Receivables and Contract Liabilities

	Balance at December 31, 2018		Additions		Deductions		Balance at December 31, 2019
Receivables	$	6,528	$	11,250	$	(17,378)	$	400
Contract liabilities:
Deferred revenue	$	34,939	$	10,000	$	(26,674)	$	18,265