Stock-Based Compensation (Tables)
|
9 Months Ended |
Sep. 30, 2018 |
|---|
| Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] |
|
| Summary of Stock Option Activity |
The following table summarizes the stock option activity during the nine months ended September 30, 2018:
|
|
|
Stock
Option
Shares |
|
|
Weighted Average
Exercise
Price |
|
|
Weighted Average
Remaining
Contractual
Term (in Years) |
|
|
Aggregate
Intrinsic
Value |
|
|
Outstanding, January 1, 2018 |
|
|
1,912,980 |
|
|
$ |
3.72 |
|
|
|
8.24 |
|
|
$ |
2,738,704 |
|
|
Granted |
|
|
1,612,700 |
|
|
|
3.64 |
|
|
|
|
|
|
|
|
|
|
Exercised |
|
|
(52,099 |
) |
|
|
1.47 |
|
|
|
|
|
|
|
|
|
|
Expired/cancelled |
|
|
(124,949 |
) |
|
|
3.23 |
|
|
|
|
|
|
|
|
|
|
Outstanding, September 30, 2018 |
|
|
3,348,632 |
|
|
$ |
3.73 |
|
|
|
8.47 |
|
|
$ |
1,129,828 |
|
|
Expected to vest, September 30, 2018 |
|
|
2,436,229 |
|
|
$ |
4.27 |
|
|
9.41 |
|
|
$ |
61,555 |
|
|
Options exercisable, September 30, 2018 |
|
|
912,403 |
|
|
$ |
2.28 |
|
|
|
5.96 |
|
|
$ |
1,068,273 |
|
|
| Summary of Restricted Stock Activity |
A summary of the Company’s restricted stock activity and related information during the nine months ended September 30, 2018 is as follows:
|
|
|
Restricted
Stock
Shares |
|
|
Weighted Average
Grant Date
Fair Value |
|
|
Nonvested, January 1, 2018 |
|
|
91,576 |
|
|
$ |
2.12 |
|
|
Granted |
|
|
60,000 |
|
|
|
4.75 |
|
|
Vested |
|
|
(142,205 |
) |
|
|
3.23 |
|
|
Forfeited |
|
|
(2,333 |
) |
|
|
2.25 |
|
|
Nonvested, September 30, 2018 |
|
|
7,038 |
|
|
$ |
2.21 |
|
|
| Summary of Recognized Compensation Cost Related to Employee and Non-employee Stock-Based Compensation Activity |
The Company recognized the following compensation cost related to employee and non-employee stock-based compensation activity:
|
|
|
Three Months Ended September 30, |
|
|
Nine Months Ended September 30, |
|
|
|
|
2018 |
|
|
2017 |
|
|
2018 |
|
|
2017 |
|
|
Research and development |
|
$ |
139,492 |
|
|
$ |
88,443 |
|
|
$ |
313,505 |
|
|
$ |
276,778 |
|
|
General and administrative |
|
|
666,919 |
|
|
|
38,916 |
|
|
|
2,450,385 |
|
|
|
117,490 |
|
|
Total |
|
$ |
806,411 |
|
|
$ |
127,359 |
|
|
$ |
2,763,890 |
|
|
$ |
394,268 |
|
|
| Stock Options Valuation Assumptions |
The calculation was based on the following assumptions.
|
|
|
Three Months Ended |
|
|
Nine Months Ended |
|
|
|
|
September 30, 2018 |
|
|
September 30, 2018 |
|
|
Expected term (years) |
|
6.00 |
|
|
6.07 |
|
|
Risk-free interest rate |
|
2.83% |
|
|
2.85% |
|
|
Expected volatility |
|
65.12% |
|
|
66.04% |
|
|
Expected dividend yield |
|
0.00% |
|
|
0.00% |
|
|