Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2015

Summary of Stock-based Compensation Expense Recognized

During the years ended December 31, 2015 and 2014, the Company recognized the following stock-based compensation expense:

	Year Ended December 31,
	2015		2014
Stock-based compensation expense by type of award:
Stock options	$	949,955	$	—
Restricted stock and restricted stock units		1,608,049		6,258
Employee stock purchase plan		43,444		—
Total stock-based compensation expense included    in expenses	$	2,601,448	$	6,258
Stock-based compensation expense by line item:
Research and development expenses	$	852,200	$	2,643
General and administrative expenses		1,749,248		3,615
Total stock-based compensation expense included    in expenses	$	2,601,448	$	6,258

Schedule of Unrecognized Stock-based Compensation Expense, Net of Estimated Forfeitures, by Type of Award and Weighted-average Recognition Period

The following table sets forth the Company’s unrecognized stock-based compensation expense, net of estimated forfeitures, by type of award and the weighted-average period over which that expense is expected to be recognized:

	As of  December 31, 2015
	Unrecognized Expense, Net of Estimated Forfeitures		Weighted- average Recognition Period (in years)
Type of award:
Stock options	$	1,409,808		2.61
Restricted stock and restricted stock units	$	2,442,289		2.58

Summary of Restricted Shares Granted and Stock Units Activity

The following table is a summary of restricted shares granted during the year ended December 31, 2015:

	Shares			Weighted- Average Grant Date Fair Value
Unvested at December 31, 2014		2,018,752		$	0.08
Granted		462,090		$	9.49
Vested		(702,165	)	$	1.37
Forfeited		(105,000	)	$	9.49
Repurchased		(1,005,714	)	$	0.03
Unvested at December 31, 2015		667,963		$	3.68

Summary of Stock Option Activity

The following table summarizes stock option activity during the year ended December 31, 2015:

	Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)
Options outstanding at December 31, 2014		—		$	—		—
Granted		443,894		$	8.49		—
Exercised		—		$	—		—
Cancelled		(78,500	)	$	8.54		—
Options outstanding at December 31, 2015		365,394		$	8.48		9.39
Options exercisable at December 31, 2015		40,250		$	9.49		9.35

Schedule of Weighted Average Assumptions using Black-Scholes Option Pricing Model

As stock-based compensation expense recognized is based on options ultimately expected to vest, the fair value of each employee option grant during the year ended December 31, 2015 was estimated on the date of grant using the Black-Scholes option pricing model with the following weighted average assumptions:

	Year Ended December 31, 2015
Expected volatility		85.2	%
Expected term (in years)		6.49
Risk-free interest rate		1.81	%
Expected dividend yield		0	%

Common Stock Reserved For Future Issuance

Common stock reserved for future issuance as of December 31, 2015 and 2014 is as follows:

Common Stock Reserved for Future Issuance	December 31,
	2015		2014
Common stock warrants		82,500	—
Restricted stock units		75,750	—
Common stock options		365,394	—
Available for grant under the 2014 Plan		773,629	—
Available for issuance under Employee Stock Purchase Plan		452,620	—
Shares issuable upon conversion of Ligand debt		670,902		695,733
		2,420,795		695,733

Restricted stock units [Member]

Summary of Restricted Shares Granted and Stock Units Activity

The following table summarizes restricted stock units activity during the year ended December 31, 2015:

	Shares			Weighted- Average Grant Date Value
Unvested at December 31, 2014		—		$	—
Granted		84,000		$	8.18
Vested		—		$	—
Forfeited		(8,250	)	$	7.27
Repurchased		—		$	—
Unvested December 31, 2015		75,750		$	8.27