Commitments and Contingencies - Additional Information (Detail)	1 Months Ended			12 Months Ended
	Jul. 31, 2014 USD ($)	Apr. 30, 2014 USD ($)	May. 31, 2013 USD ($) shares	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Feb. 28, 2015 USD ($)	Feb. 28, 2015 CAD
Loss Contingencies [Line Items]
Upfront payment paid							$ 300,000
Payment in cash upon closing of financing		$ 11,000,000
Minimum financing		35,000,000
Milestone payment upon regulatory authority approval		$ 3,000,000
Manufacturing costs obligation	$ 100,000
Milestone payment not accrued				$ 3,000,000	$ 3,000,000
Total rent expense for operating leases				$ 300,000	$ 100,000	$ 34,000
Novosom License Agreement [Member]
Loss Contingencies [Line Items]
Shares of common stock issued in settlement of first milestone payment | shares			283,069
Fair marker value of common stock issued			$ 100,000
Operating Lease Agreement To Sublease Office Space [Member] | Vancouver [Member]
Loss Contingencies [Line Items]
Operating lease agreement expiration date				Feb. 27, 2018
Letter of credit issued | CAD									CAD 50,000
Collateralized restricted deposit								$ 50,000
Maximum [Member]
Loss Contingencies [Line Items]
Aggregate milestone payment							$ 14,500,000