Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Accrued vacation	$ 75	$ 54
Accrued wages and incentive	870	796
Accrued clinical & consulting	153	202
Accrued legal & patent	60	51
Accrued end of term fee	176	155
Deferred Rent	52	46
Accrued other expenses	53	13
Total accrued expenses	$ 1,439	$ 1,317