Equity Incentive Plans and Stock Based Compensation (Tables)
|
12 Months Ended |
Dec. 31, 2018 |
|---|
| Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] |
|
| Summary of Stock Option Activity Under Equity Incentive Plan |
The following table summarizes information about stock option activity assuming Threshold equity award plans were assumed by Private Molecular for years ended December 31, 2018 and 2017:
|
|
|
Outstanding Options Number of Shares
|
|
|
Weighted Average Exercise Price
|
|
|
Weighted Average Remaining Contractual Term
|
|
|
Aggregate Intrinsic Value of December 31, 2018 (in millions):
|
|
|
Balances, December 31, 2016
|
|
|
941,684
|
|
|
$
|
0.92
|
|
|
|
5.7
|
|
|
$
|
0.9
|
|
|
Options assumed in merger (1)
|
|
|
963,681
|
|
|
$
|
33.62
|
|
|
|
|
|
|
|
|
|
|
Options granted
|
|
|
1,116,627
|
|
|
|
8.30
|
|
|
|
|
|
|
|
|
|
|
Options exercised
|
|
|
(17,473
|
)
|
|
|
3.66
|
|
|
|
|
|
|
|
|
|
|
Options canceled
|
|
|
(235,808
|
)
|
|
|
35.48
|
|
|
|
|
|
|
|
|
|
|
Balances, December 31, 2017
|
|
|
2,768,711
|
|
|
$
|
12.07
|
|
|
|
5.6
|
|
|
$
|
11.0
|
|
|
Options granted
|
|
|
1,844,787
|
|
|
|
6.98
|
|
|
|
|
|
|
|
|
|
|
Options exercised
|
|
|
(407,682
|
)
|
|
|
0.70
|
|
|
|
|
|
|
|
|
|
|
Options canceled
|
|
|
(202,817
|
)
|
|
|
20.83
|
|
|
|
|
|
|
|
|
|
|
Balances, December 31, 2018
|
|
|
4,002,999
|
|
|
$
|
10.43
|
|
|
|
6.4
|
|
|
$
|
1.5
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Vested and expected to vest December 31, 2018
|
|
|
4,002,999
|
|
|
$
|
10.43
|
|
|
|
6.4
|
|
|
$
|
1.5
|
|
|
Exercisable at December 31, 2018
|
|
|
1,607,856
|
|
|
$
|
15.19
|
|
|
|
3.7
|
|
|
$
|
1.5
|
|
|
|
(1)
|
Private Molecular, as an accounting acquirer assumed stock options covering an aggregate of 963,681 shares of common stock.
|
|
| Stock Options Outstanding and Exercisable by Exercise Price |
At December 31, 2018, stock options outstanding and exercisable by exercise price were as follows:
|
|
|
|
|
Options Outstanding
|
|
|
Options Exercisable
|
|
|
Range of
Exercise
Prices
|
|
|
Number
Outstanding
|
|
|
Weighted
Average
Remaining
Contractual
Life (Years)
|
|
|
Weighted
Average
Exercise
Price
|
|
|
Number
Exercisable
|
|
|
Weighted
Average
Exercise
Price
|
|
|
$
|
0.42–1.27
|
|
|
|
469,797
|
|
|
|
4.74
|
|
|
$
|
1.05
|
|
|
|
469,797
|
|
|
$
|
1.05
|
|
|
$
|
1.85–6.05
|
|
|
|
423,710
|
|
|
|
4.78
|
|
|
$
|
5.22
|
|
|
|
243,127
|
|
|
$
|
5.44
|
|
|
$
|
6.31–6.31
|
|
|
|
1,389,634
|
|
|
|
8.53
|
|
|
$
|
6.31
|
|
|
|
60,313
|
|
|
$
|
6.31
|
|
|
$
|
7.14–9.28
|
|
|
|
459,209
|
|
|
|
4.94
|
|
|
$
|
7.71
|
|
|
|
134,911
|
|
|
$
|
7.67
|
|
|
$
|
9.40–18.04
|
|
|
|
947,539
|
|
|
|
7.31
|
|
|
$
|
10.91
|
|
|
|
386,598
|
|
|
$
|
12.37
|
|
|
$
|
18.59–79.42
|
|
|
|
313,110
|
|
|
|
0.69
|
|
|
$
|
52.42
|
|
|
|
313,110
|
|
|
$
|
52.42
|
|
|
$
|
0.42–79.42
|
|
|
|
4,002,999
|
|
|
|
6.37
|
|
|
$
|
10.43
|
|
|
|
1,607,856
|
|
|
$
|
15.19
|
|
|
| Stock-Based Compensation Expense |
Stock-based compensation expense, which consists of the compensation cost for employee stock options and the value of options issued to non-employees for services rendered, was allocated to research and development and general and administrative in the consolidated statements of operations as follows (in thousands):
|
|
|
Years Ended December 31,
|
|
|
|
|
2018
|
|
|
2017
|
|
|
Stock-based compensation expense:
|
|
|
|
|
|
|
|
|
|
Research and development
|
|
$
|
1,192
|
|
|
$
|
340
|
|
|
General and administrative
|
|
|
2,800
|
|
|
|
1,452
|
|
|
|
|
$
|
3,992
|
|
|
$
|
1,792
|
|
|
| Weighted-Average Fair Value Valuation Assumptions |
The fair value of employee stock options was estimated using the following weighted-average assumptions for the years ended December 31, 2018 and 2017:
|
|
|
Years Ended December 31,
|
|
|
|
|
2018
|
|
|
2017
|
|
|
Employee Stock Options
|
|
|
|
|
|
|
|
|
|
Risk-free interest rate
|
|
|
2.8
|
%
|
|
|
2.1
|
%
|
|
Expected life (in years)
|
|
|
6.03
|
|
|
|
6.07
|
|
|
Dividend yield
|
|
|
—
|
|
|
|
—
|
|
|
Volatility
|
|
|
107
|
%
|
|
|
110
|
%
|
|
Weighted-average fair value of stock options granted
|
|
$
|
5.79
|
|
|
$
|
6.94
|
|
|