Net loss per share (Tables)

3 Months Ended

Mar. 31, 2014

Earnings Per Share [Abstract]

Schedule of Computation of Basic and Diluted Earnings Per Share

The detail of the computation of basic and diluted earnings per share is as follows:

	THREE MONTHS ENDED MARCH 31, 2014			THREE MONTHS ENDED MARCH 31, 2013			DECEMBER 26, 2003 (INCEPTION) TO MARCH 31, 2014
Numerator
Net loss and comprehensive loss incurred in the development stage	$	(4,227,678	)	$	(1,010,267	)	$	(51,502,587	)
Accretion for liquidation preference on preferred stock		(1,132,893	)		(1,157,865	)		(18,566,008	)
Accretion for share issuance costs on preferred stock		(19,550	)		(44,307	)		(1,014,667	)
Tax expense on preferred stock		(100,291	)		(346,091	)		(1,897,702	)
Reversal of tax payable on preferred stock due to conversion of preferred stock		1,897,702			—			1,897,702
Extinguishment of remaining share issuance costs due to conversion of preferred stock		(439,227	)		—			(439,227	)
Total loss attributable to common stockholders	$	(4,021,937	)	$	(2,558,530	)	$	(71,522,489	)
Denominator
Weighted average shares used to compute basic net loss per common share		3,148,481			301,745			398,573
Effect of potentially dilutive securities:
Stock options		—			—			—
Common stock warrants		—			—			—
Weighted average shares used to compute diluted net loss per common share		3,148,481			301,745			398,573
Net loss per share attributable to common stockholders—basic	$	(1.28	)	$	(8.48	)	$	(179.45	)
Net loss per share attributable to common stockholders—diluted	$	(1.28	)	$	(8.48	)	$	(179.45	)

Schedule of Antidilutive Securities Excluded from Computation of Basic and Diluted Net Loss Per Share

The following have been excluded from the computation of basic and diluted net loss per share as their effect would have been antidilutive:

	THREE MONTHS ENDED MARCH 31, 2014		THREE MONTHS ENDED MARCH 31, 2013
Convertible preferred stock		—		5,525,844
Outstanding stock options		630,159		435,141
Common stock warrants		11,363		—
Total		641,522		5,960,985