Intangible Assets

9 Months Ended

Sep. 30, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible assets are amortized over their estimated useful lives and reviewed for impairment when events and changes in circumstances indicate that the carrying amount may not be recoverable. During the three and nine months ended September 30, 2018 and 2017, there were no impairment charges recorded. Additionally, the Company reviewed the useful lives of the intangibles as of September 30, 2018 and believes the useful lives are still reasonable.

Intangible asset balances as of September 30, 2018 and December 31, 2017 are as follows:




	September 30, 2018
	Gross Carrying Value		Accumulated Amortization			Net Carrying Value
	(in thousands)
Developed technology - lomitapide	$	42,300	$	(7,214	)	$	35,086
Developed technology - metreleptin	210,158		(38,794		)	171,364
Total intangible assets	$	252,458	$	(46,008	)	$	206,450




	December 31, 2017
	Gross Carrying Value		Accumulated Amortization			Net Carrying Value
	(in thousands)
Developed technology - lomitapide	$	42,300	$	(4,262	)	$	38,038
Developed technology - metreleptin	210,158		(22,924		)	187,234
Total intangible assets	$	252,458	$	(27,186	)	$	225,272

Amortization expense was $6.3 million for both three-month periods ended September 30, 2018 and 2017 and $18.8 million for both nine-month periods ended September 30, 2018 and 2017.

As of September 30, 2018, the estimated amortization expense related to intangibles for future periods is as follows:




	Amount
Years Ending December 31,	(in thousands)
2018 (remaining 3 months)	$	6,273
2019	25,095
2020	25,095
2021	25,095
2022	25,095
Thereafter	99,797
Total intangible assets subject to amortization	$	206,450