Commitments and Contingencies - Additional Information (Detail) - USD ($)	1 Months Ended				3 Months Ended		12 Months Ended
	Jan. 31, 2016	Jul. 31, 2014	Apr. 30, 2014	May. 31, 2013	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2012
Lease Agreements [Member]
Loss Contingencies [Line Items]
Total rent expense for operating leases					$ 100,000	$ 35,000
License Agreements [Member]
Loss Contingencies [Line Items]
Upfront payment paid							$ 300,000
Shares of common stock issued in settlement of first milestone payment				283,069
Fair marker value of common stock issued				$ 100,000
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
Operating Lease Agreement To Lease Office Space [Member] | San Francisco [Member]
Loss Contingencies [Line Items]
Operating lease agreement expiration date	Apr. 30, 2019
Operating Lease Agreement To Sublease Office Space [Member] | Vancouver [Member]
Loss Contingencies [Line Items]
Operating lease agreement expiration date					Feb. 27, 2018
Collateralized restricted deposit					$ 25,000
Maximum [Member] | License Agreements [Member]
Loss Contingencies [Line Items]
Aggregate milestone payment							$ 14,500,000