6.	Stock-Based Compensation

2015

Equity Plan

The

2015

Equity Plan provides for increases to the number of shares reserved for issuance thereunder each

January 1

equal to

4.0%

of the total shares of the Company's common stock outstanding as of the immediately preceding

December 31,

unless a lesser amount is stipulated by the Compensation Committee of the Company's board of directors. Accordingly,

1,339,215

shares were added to the reserve as of

January 1, 2020,

which shares

may

be issued in connection with the grant of stock-based awards, including stock options, restricted stock, restricted stock units, stock appreciation rights and other types of awards as deemed appropriate, in each case, in accordance with the terms of the

2015

Equity Plan. As of

September

30,

2020,

there were

shares of common stock available for future issuance under the

2015

Equity Plan. Further, the Company granted an option to purchase

70,000

shares of common stock to an employee during the

nine

months ended

September 30, 2020

that were granted outside of the

2015

Equity Plan as an inducement material to the employee's acceptance of employment with the Company in accordance with Nasdaq Listing Rule

5635

(c)(

The Company recorded stock-based compensation expense in the following expense categories of its unaudited interim consolidated statements of operations for the periods indicated:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2020		2019		2020		2019
Research and development	$	19,838	$	13,519	$	136,236	$	40,692
General and administrative		259,635		131,802		448,061		344,913
Total stock-based compensation expense	$	279,473	$	145,321	$	584,297	$	385,605

The following table summarizes the activity related to all stock options for the

nine

months ended

September

30,

2020:

	Number of Options			Weighted average exercise price per share		Weighted average remaining contractual life (in years)
Balance at January 1, 2020		309,276		$	55.78
Granted		1,731,100			0.66
Expired		(172	)		142.50
Outstanding at September 30, 2020		2,040,204		$	9.01		9.1
Exercisable at September 30, 2020		992,779		$	17.65		8.4

The weighted average grant date fair value of stock option awards granted during the

nine

months ended

September

30,

2020

was

$0.62.

The total fair value of options vested during the

three

months ended

September 30, 2020

and

2019

was

$0.3

million and

$0.2

million, respectively. The total fair value of options vested during the

nine

months ended

September 30, 2020

and

2019

was

$0.6

million and

$0.5

million, respectively.

options were exercised during any of the periods presented. At

September

30,

2020,

there was

$0.8

million of unrecognized compensation expense that will be recognized over a weighted-average period of

2.1

years.

Options granted were valued using the Black-Scholes option-pricing model and the weighted average assumptions used to value the options granted during the

nine

months ended

September

30,

2020

and

2019

were as follows:

	2020			2019
Expected term (in years)		7.75			5.52
Risk-free interest rate		0.9	%		2.2	%
Expected volatility		119.7	%		113.4	%
Dividend yield		—	%		—	%

Restricted Stock Awards

During the

nine

months ended

September

30,

2020,

the Company granted

153,000

restricted stock awards to members of the board of directors of the Company. The weighted average grant date fair value of the restricted stock awards granted during the

nine

months ended

September

30,

2020

was

$0.65.

The shares begin to vest

months after the grant date. The Company recognized approximately

$4,000

and

$12,000

in expense related to these awards during the

three

and

nine

months ended

September

30,

2020,

respectively. At

September

30,

2020,

there was approximately

$88,000

of unrecognized compensation cost that will be recognized over a weighted average period of

2.66

years.