6 Intangible assets

The Company's finite-lived intangible assets include acquired licenses and acquired research and development ("acquired R&D") and are presented in the following table:

	December 31, 2016									December 31, 2015
	Average remaining life		Historical costs		Accumulated amortization			Carrying amount		Historical costs		Accumulated amortization			Carrying amount
	in thousands, except for average remaining life
Licenses		14.8	$	7,799	$	(3,952	)	$	3,847	$	5,730	$	(3,816	)	$	1,914
Acquired R&D		17.3		4,908		(431	)		4,477		5,080		(179	)		4,901

Total		16.2	$	12,707	$	(4,383	)	$	8,324	$	10,810	$	(3,995	)	$	6,815

All intangible assets are owned by Dutch entities.

As of December 31, 2016, the estimated future amortization expense for each of the five succeeding years and the period thereafter is as follows:

Years	Amount
	($ in thousands)
2017	$	569
2018		566
2019		533
2020		513
2021		509
Thereafter		5,634

Total	$	8,324

a. Acquired licenses

The carrying amount of the Company's licenses by licensor is set out below.

	December 31, 2016		December 31, 2015
	in thousands
National Institutes of Health	$	738	$	866
St. Jude Children's Hospital		659		723
Protein Sciences Corporation		2,194		49
Other		256		276

Total	$	3,847	$	1,914

The amortization expense related to licenses for the year ended December 31, 2016 was $0.3 million (December 31, 2015: $0.4 million; December 31, 2014: $0.6 million) and is included in research and development expenses.

Protein Sciences Corporation

In 2016, the Company renegotiated its existing license contract with Protein Sciences Corporation for the exclusive use of its expresSF+ ("SF+") insect cell line to provide the Company with an exclusive royalty free, perpetual right and license to the licensed technology in the field of AAV-based gene therapy. Capitalized cost includes an amount paid of $0.1 million in 2013 and $2.2 million in 2016.

Glybera impairment

Triggered by the first commercial sale of Glybera in September 2015, the Company assessed the value-in-use of Glybera related licenses (Xenon and Ampliphi). The value-in-use was determined using a discounted cash flow model based on the Company's forecast of net cash flows to be generated by the sale of Glybera in Europe through 2021. In determining the value-in-use the Company applied a WACC of 13.5%. Accordingly, the Company recognized an impairment loss of $1.3 million in the year ended December 31, 2015, which is charged to research and development expense.

There were no other material additions in 2016.

b. Acquired R&D

The Acquired R&D asset was acquired as part of the acquisition of InoCard in July 2014 and relates to the S100A1 program. Following the commercialization of S100A1 as part of the collaboration agreement with BMS in May 2015, amortization commenced on the Acquired R&D asset on a straight-line basis over a 19-year period in line with the recognition of license revenue originating from the BMS collaboration.

The amortization expense related to Acquired R&D for the year ended December 31, 2016 was $0.3 million (December 31, 2015: $0.2 million; December 31, 2014: $0.0 million) and is included in research and development expenses.