Atara Biotherapeutics Quarterly report pursuant to Section 13 or 15(d)

Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2020

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

The following is a summary of RSU activity under our 2014 EIP and Inducement Plan:

	RSUs
	Shares			Weighted Average Grant Date Fair Value
Unvested as of December 31, 2019		1,910,764		$	26.93
Granted		3,880,991		$	12.09
Forfeited		(650,540	)	$	19.18
Vested		(1,096,522	)	$	20.14
Unvested as of September 30, 2020		4,044,693		$	15.78

Summary of Stock Option Activity

The following is a summary of stock option activity under our 2014 EIP and Inducement Plan. The table below also includes the activity relating to options for 275,000 shares of our common stock which were issued in 2017 outside of these plans:

	Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (in thousands)
Outstanding as of December 31, 2019		6,934,262		$	28.25
Granted		2,504,925			11.75
Exercised		(132,911	)		13.47
Forfeited or expired		(1,081,714	)		30.89
Outstanding as of September 30, 2020		8,224,562		$	23.12		6.5	$	3,985

Schedule of Common Stock Reserved for Future Issuance Under Equity Incentive Plans

The following shares of common stock were reserved for future issuance under our equity incentive plans as of September 30, 2020:

	Total Shares Reserved
2014 Equity Incentive Plan		13,803,560
2018 Inducement Plan		2,634,836
2014 Employee Stock Purchase Plan		1,066,654
Total reserved shares of common stock		17,505,050

Schedule of Stock-based Compensation, Related to Employee and Nonemployee Stock Awards

Total stock-based compensation expense related to all employee and non-employee stock awards was as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2020		2019		2020		2019
	(in thousands)				(in thousands)
Research and development	$	8,151	$	7,003	$	24,341	$	19,740
General and administrative		5,104		5,149		15,506		19,882
Total stock-based compensation expense	$	13,255	$	12,152	$	39,847	$	39,622