Changes in Balances of Company's Receivables and Contract Liabilities

The following table presents changes in the balances of the Company’s Celgene receivables and contract liabilities during the three months ended March 31, 2019:

(in thousands)	Balance at beginning of period		Additions		Deductions			Balance at end of period
Receivables	$	6,528	$	—	$	(2,705	)	$	3,823
Contract liabilities:
Deferred revenue	$	34,939	$	—	$	(8,671	)	$	26,268

Summary of Revenue Recognized or Expense Incurred Related to Combined Unit of Accounting for its License and Vector Manufacturing of bb2121

The following table summarizes the net collaboration revenue recognized or expense incurred related to the combined performance obligation for the license and vector manufacturing of ide-cel in the U.S. for the three months ended March 31, 2019, and 2018:

	For the three months ended March 31,
Ide-cel license and manufacturing services - U.S. (in thousands)	2019			2018
ASC 808 ide-cel license and manufacturing revenue - U.S. (1)	$	—		$	3,761
ASC 808 ide-cel license and manufacturing research and development expense - U.S. (1)	$	(3,244	)	$	—

(1)

As noted above, the calculation of collaboration revenue or research and development expense to be recognized for the Company’s combined performance obligation for its license and vector manufacturing of ide-cel 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.

Summary of Revenue Recognized or Expense Incurred Related to Combined Unit of Accounting for its License and Vector Manufacturing of bb2121

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 three months ended March 31, 2019, and 2018:

For the three months ended March 31,

Ide-cel license and manufacturing services - outside of U.S.

(in thousands)

2019

2018

ASC 606 license and manufacturing revenue

- outside of U.S.

$

9,064

$

8,942

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 March 31, 2019:

(in thousands)	Ide-cel transaction price as of March 31, 2019
Up-front non-refundable payment - Celgene Collaboration Agreement	$	75,000
Up-front non-refundable payment - Amended Celgene Collaboration Agreement		25,000
Ide-cel license fee - Ide-cel License Agreement		10,000
Estimated variable consideration		84,664
	$	194,664

(in thousands)	Allocation of transaction price to performance obligations		Transaction price unsatisfied as of March 31, 2019
Ide-cel research and development services	$	38,438	$	—
Ide-cel license and manufacturing services		156,226		32,821
	$	194,664	$	32,821

Summary of Revenue Recognized or Revenue Adjustment Recorded 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 three months ended March 31, 2019 and 2018:

	For the three months ended March 31,
(in thousands)	2019			2018
Ide-cel research and development services revenue (revenue adjustment)	$	(209	)	$	2,183
	$	(209	)	$	2,183

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 March 31, 2019:

(in thousands)	bb21217 transaction price as of March 31, 2019
bb21217 license fee - bb21217 License Agreement	$	15,000
Estimated variable consideration		26,687
	$	41,687

(in thousands)	Allocation of transaction price to performance obligations		Transaction price unsatisfied as of March 31, 2019
bb21217 research and development services	$	5,444	$	1,118
bb21217 license and manufacturing services		36,243		36,243
	$	41,687	$	37,361

Summary of Revenue Recognized or Revenue Adjustment Recorded Related to Research and Development Services

The following table summarizes the revenue recognized related to the bb21217 research and development services for the three months ended March 31, 2019, and 2018:

	For the three months ended March 31,
(in thousands)	2019		2018
bb21217 research and development services revenue	$	721	$	721
	$	721	$	721