Accrued Expenses and Other Current Liabilities (Tables)

12 Months Ended

Dec. 31, 2017

Accrued Expenses and Other Current Liabilities

Schedule of accrued expenses and other current liabilities

	As of December 31
(in thousands)	2016		2017
Research and development related costs	$	8,716	$	2,308
Payroll and related costs		2,345		4,426
Accounting, tax and audit services		484		231
Other		1,781		1,159
Total other current liabilities	$	13,326	$	8,124