Quarterly report pursuant to Section 13 or 15(d)

Common Stock - Schedule of Reserved Shares of Common Stock for Future Issuance (Detail)

v3.2.0.727
Common Stock - Schedule of Reserved Shares of Common Stock for Future Issuance (Detail) - shares
Jun. 30, 2015
Dec. 31, 2014
Class of Stock [Line Items]    
Outstanding stock options 1,153,369 615,322
Outstanding Series C-1 Preferred warrants 14,033 14,033
Total common shares reserved for future issuance 2,163,225 847,711
2014 Equity Incentive Plan [Member]    
Class of Stock [Line Items]    
Possible future issuance under equity compensation plan (shares) 618,773 180,610
2014 Employee Stock Purchase Plan [Member]    
Class of Stock [Line Items]    
Possible future issuance under equity compensation plan (shares) 52,050 37,746
2015 Inducement Plan [Member]    
Class of Stock [Line Items]    
Possible future issuance under equity compensation plan (shares) 325,000 0