Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2019

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Schedule of Stock-Based Compensation Expense Related to Equity Awards Granted to Employees and Consultants

The following table sets forth stock-based compensation expense related to equity awards granted to employees and consultants for all periods presented (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2019		2018		2019		2018
Research and development	$	3,795	$	2,050	$	6,758	$	3,641
Selling, general and administrative		4,843		2,732		8,861		4,772
Total	$	8,638	$	4,782	$	15,619	$	8,413

Summary of Stock Option and Other Equity Award Activity Under Plans

The following summarizes option and other equity award activity under the 2012 Equity Incentive Plan and 2015 Stock Option and Incentive Plan: 

	Shares Subject to			Weighted Average
	Outstanding Options			Exercise Price per Share
Balance at December 31, 2018		3,701,461		$	26.40
Options granted		1,179,253			41.34
Options exercised		(88,629	)		11.23
Options canceled/forfeited		(71,235	)		32.24
Balance at June 30, 2019		4,720,850			30.33
	Shares Subject to			Weighted Average
	Outstanding Awards			Grant Date Fair Value
Balance at December 31, 2018		162,946		$	53.37
RSUs awarded		460,149			41.54
RSUs released		(32,523	)		52.06
RSUs forfeited		(8,154	)		47.25
Balance at June 30, 2019		582,418			44.19