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 six months ended June 30, 2019:

(in thousands)	Balance at beginning of period		Additions		Deductions			Balance at end of period
Receivables	$	6,528	$	10,450	$	(6,528	)	$	10,450
Contract liabilities:
Payable included in accrued expenses	$	—	$	3,781	$	—		$	3,781
Deferred revenue	$	34,939	$	10,000	$	(21,716	)	$	23,223

Summary of Revenue Recognized or Expense Incurred for Joint Ide-cel Development Efforts 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 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 for development in the U.S., for the three and six months ended June 30, 2019, and 2018:

	For the three months ended June 30,						For the six months ended June 30,
(in thousands)	2019			2018			2019			2018
ASC 808 ide-cel revenue - U.S. (1)	$	—		$	—		$	—		$	3,761
ASC 808 ide-cel research and development expense - U.S. (1)	$	(1,065	)	$	(3,349	)	$	(4,309	)	$	(3,349	)

(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.

Summary of Revenue Recognized or Expense Incurred for Joint Ide-cel Development Efforts 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 and six months ended June 30, 2019, and 2018:

For the three months ended

June 30,

For the six months ended

June 30,

(in thousands)

2019

2018

2019

2018

ASC 606 ide-cel license and

manufacturing revenue - outside of U.S.

$

7,899

$

5,764

$

16,963

$

14,706

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 June 30, 2019:

(in thousands)	Ide-cel transaction price as of June 30, 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
Ide-cel development milestone		10,000
Estimated variable consideration		87,189
	$	207,189

(in thousands)	Allocation of transaction price to performance obligations		Transaction price unsatisfied as of June 30, 2019
Ide-cel research and development services	$	40,912	$	—
Ide-cel license and manufacturing services		166,277		26,723
	$	207,189	$	26,723

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 and six months ended June 30, 2019 and 2018:

	For the three months ended June 30,				For the six months ended June 30,
(in thousands)	2019		2018		2019		2018
Ide-cel research and development services revenue	$	2,473	$	953	$	2,264	$	3,136
	$	2,473	$	953	$	2,264	$	3,136

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 June 30, 2019:

(in thousands)	bb21217 transaction price as of June 30, 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 June 30, 2019
bb21217 research and development services	$	5,444	$	721
bb21217 license and manufacturing services		36,243		36,243
	$	41,687	$	36,964

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 and six months ended June 30, 2019, and 2018:

	For the three months ended June 30,				For the six months ended June 30,
(in thousands)	2019		2018		2019		2018
bb21217 research and development services revenue	$	721	$	721	$	1,442	$	1,442
	$	721	$	721	$	1,442	$	1,442