Stock Based Compensation (Tables)

3 Months Ended

Mar. 31, 2020

Share-based Payment Arrangement [Abstract]

Summary of Stock Option Activity

The following table summarizes stock option activity under our 2013 Equity Incentive Plan (the “2013 Plan”) and our Inducement Plan, and related information during the three months ended March 31, 2020:

	Shares Subject to Outstanding Options		Weighted- Average Exercise Price Per Share
Balance at December 31, 2019	7,548,436		$	32.21
Options granted	1,689,360		12.32
Options exercised	(35,654	)	9.12
Options canceled	(401,547	)	31.49
Balance at March 31, 2020	8,800,595		$	28.52

Summary of PSO Activities

The following table summarizes PSO activities under our 2013 Plan and related information during the three months ended March 31, 2020:

	Shares Subject to Outstanding PSOs		Weighted- Average Exercise Price Per Share
Balance at December 31, 2019	552,010		$	31.43
Options granted	575,625		12.79
Options exercised	(2,293	)	23.76
Options canceled	(430,799	)	33.29
Balance at March 31, 2020	694,543		$	14.85

Summary of RSU Activity

The following table summarizes RSU activity under our 2013 Plan and our Inducement Plan, and related information during the three months ended March 31, 2020:

	Shares Subject to Outstanding RSUs		Weighted- Average Grant Date Fair Value Per Share
Balance at December 31, 2019	1,274,217		$	29.86
RSUs granted	947,442		12.42
RSUs released	(355,665	)	31.35
RSUs canceled	(78,246	)	26.53
Balance at March 31, 2020	1,787,748		$	20.46

Summary of PSU Activity

The following table summarizes PSU activity under our 2013 Plan and related information during the three months ended March 31, 2020:

	Subject to Outstanding PSUs		Weighted- Average Grant Date Fair Value Per Share
Balance at December 31, 2019	11,925		$	32.66
PSUs granted	865,500		13.06
PSUs released	(11,925	)	32.66
Balance at March 31, 2020	865,500		$	13.06

 

Classification of Stock-Based Compensation Expense

The table below sets forth the functional classification of stock-based compensation expense for the periods presented (in thousands):

	Three Months Ended March 31,
	2020			2019
Research and development	$	2,599		$	10,137
Selling, general and administrative	6,881			7,757
Stock-based compensation expense included in total expenses	$	9,480		$	17,894
Capitalized stock-based compensation costs	$	(327	)	$	(242	)