Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2018

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock Option Activity

A summary of stock option activity for the nine months ended September 30, 2018 is as follows:

						Weighted
						Average
				Weighted		Remaining
	Number of			Average Exercise		Contractual
	Shares			Price Per Share		Term in Years
Outstanding at December 31, 2017		81,482		$	113.68		8.80
Granted		58,994		$	2.96		7.43
Exercised		—			—
Cancelled/forfeited/expired		(25,835	)	$	45.83		8.68
Outstanding at September 30, 2018		114,641		$	72.02		8.79
Vested and unvested expected to vest at September 30, 2018		112,280		$	73.23		8.77

Assumptions Used for Determining Fair Value of Stock Options Under Black-Scholes Pricing Model

The assumptions used in the Black-Scholes pricing model for stock options granted during the three and nine months ended September 30, 2018 were as follows:

Stock and exercise prices	$2.75 - $6.00
Expected dividend yield		0.00%
Discount rate-bond equivalent yield	2.73% – 2.97%
Expected life (in years)	5.00 – 5.96
Expected volatility	100% - 120%

Summary of RSU Activity

A summary of RSU activity for the nine months ended September 30, 2018 is as follows:

				Weighted
	Number of			Average Grant
	Shares			Date Fair Value
Outstanding at December 31, 2017		12,026		$	56.10
Granted		—			—
Vested and issued		(5,833	)	$	45.00
Forfeited		(5,833	)	$	45.00
Outstanding at September 30, 2018		360		$	415.80
Vested and unvested expected to vest at September 30, 2018		360		$	415.80

Effects of Stock-Based Compensation Related to Equity Awards to Employees and Nonemployees on Condensed Statement of Operations and Comprehensive Loss

The following table presents the effects of stock-based compensation related to equity awards to employees and nonemployees on the unaudited condensed statements of operations and comprehensive loss during the periods presented:

	For the three months ended				For the nine months ended
	September 30,				September 30,
	2017		2018		2017		2018
Stock Options
Cost of revenues	$	59,720	$	10,150	$	133,105	$	37,150
Research and development expenses		53,405		30,247		121,834		103,267
General and administrative expenses		178,671		57,162		528,406		243,593
Sales and marketing expenses		40,181		15,440		100,327		63,494
Total expenses related to stock options		331,977		112,999		883,672		447,504
RSUs
Cost of revenues		20,417		-		58,717		(18,802	)
Research and development expenses		20,418		-		57,490		13,576
General and administrative expenses		74,521		-		160,927		54,303
Sales and marketing expenses		28,355		-		71,343		15,348
Total stock-based compensation	$	475,688	$	112,999	$	1,232,149	$	511,929