CONSOLIDATED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' (DEFICIT) EQUITY (USD $)
In Thousands, except Share data, unless otherwise specified
Redeemable convertible preferred stock
Common stock
Additional paid-in capital
Accumulated other comprehensive (loss) income
Accumulated Deficit
Total
Balance at Dec. 31, 2011 $ 68,141 $ 1 $ 1,702 $ (2) $ (14,467) $ (12,766)
Balance (in shares) at Dec. 31, 2011 41,092,825 1,558,588        
Increase (Decrease) in Stockholders' Equity            
Net loss         (31,984) (31,984)
Unrealized gain (loss) on available-for-sale marketable securities       24   24
Accretion of redeemable convertible preferred stock to redemption value 6   (6)     (6)
Conversion of redeemable convertible preferred stock into common stock (68,147) 1 68,146     68,147
Conversion of redeemable convertible preferred stock into common stock (in shares) (41,092,825) 11,740,794        
Issuance of common stock, net of issuance costs of $1,984, $235, $43 for 2012, 2013 and 2014 respectively     56,838     56,838
Issuance of common stock, net of issuance costs of $1,984, $235, $43 for 2012, 2013 and 2014 respectively   6,325,000        
Issuance of common stock in exchange for license     1,957     1,957
Issuance of common stock in exchange for license (in shares)   192,012        
Vesting of restricted stock     16     16
Vesting of restricted stock (in shares)   542,421        
Issuance of common stock resulting from exercise of stock options     3     3
Issuance of common stock resulting from exercise of stock options (in shares)   5,395        
Obligation to issue a warrant     837     837
Stock-based compensation expense     7,400     7,400
Balance at Dec. 31, 2012   2 136,893 22 (46,451) 90,466
Balance (in shares) at Dec. 31, 2012   20,364,210        
Increase (Decrease) in Stockholders' Equity            
Net loss         (41,202) (41,202)
Unrealized gain (loss) on available-for-sale marketable securities       6   6
Issuance of common stock, net of issuance costs of $1,984, $235, $43 for 2012, 2013 and 2014 respectively   1 59,759     59,760
Issuance of common stock, net of issuance costs of $1,984, $235, $43 for 2012, 2013 and 2014 respectively   4,255,000        
Vesting of restricted stock     9     9
Vesting of restricted stock (in shares)   417,718        
Issuance of common stock resulting from exercise of stock options     33     33
Issuance of common stock resulting from exercise of stock options (in shares)   81,795        
Issuance of common stock resulting from vesting of restricted stock units and payment of tax withholdings     (1,302)     (1,302)
Issuance of common stock resulting from vesting of restricted stock units and payment of tax withholdings (in shares)   209,727        
Stock-based compensation expense     9,676     9,676
Balance at Dec. 31, 2013   3 205,068 28 (87,653) 117,446
Balance (in shares) at Dec. 31, 2013   25,328,450       25,328,000
Increase (Decrease) in Stockholders' Equity            
Net loss         (53,365) (53,365)
Unrealized gain (loss) on available-for-sale marketable securities       (17)   (17)
Issuance of common stock, net of issuance costs of $1,984, $235, $43 for 2012, 2013 and 2014 respectively     11,646     11,646
Issuance of common stock, net of issuance costs of $1,984, $235, $43 for 2012, 2013 and 2014 respectively   1,346,676        
Vesting of restricted stock     9     9
Vesting of restricted stock (in shares)   321,287        
Issuance of common stock resulting from exercise of stock options     20     20
Issuance of common stock resulting from exercise of stock options (in shares)   30,451        
Issuance of common stock resulting from vesting of restricted stock units and payment of tax withholdings     (780)     (780)
Issuance of common stock resulting from vesting of restricted stock units and payment of tax withholdings (in shares)   135,008        
Shares issued for technology rights     1,447     1,447
Shares issued for technology rights (shares)   97,500        
Stock-based compensation expense     12,360     12,360
Balance at Dec. 31, 2014   $ 3 $ 229,770 $ 11 $ (141,018) $ 88,766
Balance (in shares) at Dec. 31, 2014   27,259,372       27,259,000