(7) INTANGIBLE ASSETS

Intangible assets consisted of the following:

	December 31,
	2016			2015
Intangible assets:
Finite-lived intangible assets	$	305,122		$	129,572
Indefinite-lived intangible assets		332,199			607,548
Gross intangible assets:		637,321			737,120
Less: Accumulated amortization		(83,541	)		(53,124	)
Net carrying value	$	553,780		$	683,996

Finite-Lived Intangible Assets

The following table summarizes the net-book-value and estimated remaining life of the Company’s finite-lived intangible assets as of December 31, 2016:

	Net Balance at December 31, 2016		Average Remaining Life
Repurchased royalty rights	$	46,688	6.9 years
Acquired intellectual property		172,256	8.1 years
License payments for marketing approvals		1,869	4.9 years
SRCC in-place and above market tenant leases		768	Remaining lease terms
Total	$	221,581

As of December 31, 2016, the estimated future amortization expense associated with the Company’s finite-lived intangible assets for each of the five succeeding fiscal years is as follows:

Fiscal Year	Amount
2017	$	30,430
2018		30,400
2019		30,086
2020		27,605
2021		26,681
Thereafter		76,379
	$	221,581

Indefinite-Lived Intangible Assets

Indefinite-lived intangible assets consisted of the following:

	December 31,
	2016		2015
In-Process Research and Development:
Pegvaliase	$	326,359	$	—
Kyndrisa		—		533,064
Other exons acquired with Prosensa		—		41,044
Reveglucosidase alfa		—		25,010
Other acquired pre-clinical compounds		5,840		8,430
Net carrying value	$	332,199	$	607,548

Intangible assets related to IPR&D assets are considered to be indefinite-lived until the completion or abandonment of the associated R&D efforts. During the period the assets are considered indefinite-lived, they will not be amortized but will be tested for impairment on an annual basis and between annual tests if the Company becomes aware of any events occurring or changes in circumstances that would indicate a reduction in the fair value of the IPR&D assets below their respective carrying amounts. If and when development is complete, which generally occurs if and when regulatory approval to market a product is obtained, the associated assets would be deemed finite-lived and would then be amortized based on their respective estimated useful lives at that point in time.

Related to the Kyndrisa and other exon IPR&D assets, the Company recorded impairment charges of $198.7 million in the fourth quarter of 2015 and impairment charges of $574.1 million in the second quarter of 2016 based on the status of development efforts. These impairments reduced the remaining book value to zero due to the termination of the programs. The Company also recognized an impairment charge of $25.0 million in the second quarter of 2016 related to the reveglucosidase alfa IPR&D assets due to the decision to terminate that development program.

In 2015, the Company completed the sale of talazoparib to Medivation Inc. (Medivation). Pursuant to the Asset Purchase Agreement, Medivation paid the Company an upfront payment of $410.0 million upon the closing of the transaction. In addition, contingent upon the successful development and commercialization of talazoparib, Medivation will pay the Company milestone payments of up to $160.0 million and mid-single digit percentage royalties on net sales of talazoparib. During the fourth quarter of 2015, the Company recognized a net gain of $369.5 million related to the sale of the talazoparib intangible assets.