Research and Development Expenses

3 Months Ended

Mar. 31, 2017

Research and Development Expenses

Research and Development Expenses

4.Research and Development Expenses

Research and development expenses include the following items:

	Three Months Ended March 31,
(in thousands)	2016		2017
Research materials and purchased services	$	10,184	$	9,608
Staff costs	1,985		2,320
Other research and development expenses	838		699
Depreciation and amortization	29		33
Total	$	13,036	$	12,660

Research materials and purchased services include all expenses for materials and services in respect of research activities.

For the three months ended March 31, 2017, other research and development expenses consisted of $0.3 million in infrastructure expenses, $0.3 million in advisory and external consultancy expenses and $0.1 million in intellectual property and trademark related expenses and travel expenses.

For the three months ended March 31, 2016, other research and development expenses consisted of $0.3 million in infrastructure expenses, $0.3 million in advisory and external consultancy expenses, $0.1 million in intellectual property and trademark related expenses and $0.1 million in travel expenses.