Stock-Based Awards (Tables)

6 Months Ended

Jun. 30, 2019

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Weighted Average Assumptions to Calculate Fair Value of Stock Options

The fair value of each option award is estimated on the date of grant using a Black-Scholes option pricing model applying the weighted-average assumptions noted in the following table:

	Six Months Ended June 30, (unaudited)
	2019			2018
Expected life (in years)		6.06			5.87
Risk-free interest rates		2.5	%		2.6	%
Volatility		60.2	%		56.1	%
Dividend yield		-	%		-	%

Schedule of Stock Based Compensation Expense

Operating expenses include stock-based compensation expense as follows (in thousands):

	Three Months Ended June 30, (unaudited)				Six Months Ended June 30, (unaudited)
	2019		2018		2019		2018
Research and development	$	161	$	188	$	283	$	381
General and administrative		601		915		1,919		1,706
Total stock-based compensation expense	$	762	$	1,103	$	2,202	$	2,087

2012 Equity Incentive Plan [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Share-based Compensation, Employee Stock Purchase Plan, Activity

A summary of BioTime’s 2012 Plan activity and other stock option awards granted outside of the 2012 Plan related information is as follows (in thousands, except per share amounts):

	Shares Available for Grant			Number of Options Outstanding			Number of RSUs Outstanding			Weighted Average Exercise Price
December 31, 2018		1,885			13,867			402		$	2.44
AgeX distribution adjustment		117			(2	)		3			-
Restricted stock units vested		-			-			(135	)		-
Options granted		(2,337	)		2,337			-			1.14
Options exercised		-			-			-			-
Options expired/forfeited/cancelled		1,264			(1,264	)		-			2.09
June 30, 2019		929			14,938			270		$	2.27
Options exercisable at June 30, 2019					9,213					$	2.59

Asterias 2013 Equity Incentive Plan [Member] | Asterias Biotherapeutics, Inc. [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Share-based Compensation, Employee Stock Purchase Plan, Activity

A summary of activity under the Asterias Equity Plan from the closing date of the Asterias Merger through June 30, 2019 is as follows (in thousands, except per share amounts):

	Shares Available for Grant			Number of Options Outstanding			Number of RSUs Outstanding		Weighted Average Exercise Price
March 8, 2019		5,190			-			-	$	-
Options granted		(490	)		490			-		1.59
Options exercised		-			-			-		-
Options forfeited		105			(105	)		-		1.63
June 30, 2019		4,805			385			-		1.58
Options exercisable at June 30, 2019					-				$	-