Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation

v3.20.2
Stock-based Compensation
9 Months Ended
Sep. 30, 2020
Share-based Payment Arrangement [Abstract]  
Stock-based Compensation Stock-based Compensation
Equity Incentive Plans
In June 2019, our board of directors (the "Board") and stockholders approved the 2019 Incentive Award Plan (the "2019 Plan"). The 2019 Plan superseded and replaced in its entirety our 2010 Equity Incentive Plan (the “2010 Plan”) which was effective in March 2010, and no further awards will be granted under the 2010 Plan; however, the terms and conditions of the 2010 Plan will continue to govern any outstanding awards thereunder. 
The 2010 Plan provided for the grant of incentive stock options, non-statutory stock options, restricted stock units ("RSUs"), restricted stock awards ("RSAs"), performance-contingent restricted stock units ("PSUs"), performance based options ("PBOs"), stock appreciation rights, and stock purchase rights to our employees, non-employee directors and consultants.
The number of shares of our common stock available for issuance under the 2019 Plan is equal to the sum of (i) 7,897,144 shares, and (ii) any shares subject to awards granted under the 2010 Plan that were outstanding as of April 22, 2019 and thereafter terminate, expire, lapse or are forfeited; provided that no more than 14,000,000 shares may be issued upon the exercise of incentive stock options (“ISOs”). In June 2019, 8.1 million shares authorized for issuance under the 2019 Plan were registered under the Securities Act of 1933, as amended (the “Securities Act”).
The 2019 Plan provides for the grant of stock options, including incentive stock options and non-qualified stock options, stock appreciation rights, restricted stock, restricted stock units, other stock or cash based awards and dividend equivalents to eligible employees and consultants of the Company or any parent or subsidiary, as well as members of the Board.
Stock Options
The option exercise price for incentive stock options must be at least 100% of the fair value of our common stock on the date of grant and the option exercise price for non-statutory stock options is 85% of the fair value of our common stock on the date of grant, as determined by the Board. If, at the time of a grant, the optionee directly or by attribution owns stock possessing more than 10% of the total combined voting power of all of our outstanding capital stock, the exercise price for these options must be at least 110% of the fair value of the underlying common stock. Stock options granted to employees generally have a maximum term of 10 years and vest over four years from the date of grant, of which 25% vest at the end of one year, and 75% vest monthly over the remaining three years. We may grant options with different vesting terms from time to time. Unless an employee's termination of service is due to disability or death, upon termination of service, any unexercised vested options will be forfeited at the end of three months or the expiration of the option, whichever is earlier.
Restricted Stock Units (RSUs)
We also grant employees RSUs, which generally vest over either a three year period with one-third of the shares subject to the RSUs vesting on each yearly anniversary of the vesting commencement date or over a four year period with 25% of the shares subject to the RSU vesting on each yearly anniversary of the vesting commencement date, in each case contingent upon such employee’s continued service on such vesting date. RSUs are generally subject to forfeiture if employment terminates prior to the release of vesting restrictions. We may grant RSUs with different vesting terms from time to time.
Performance-contingent Restricted Stock Units (PSUs) and Performance Based Options (PBOs)
We also grant our executives and our non-executive employees PSUs, and we grant our executives PBOs. The PSUs and PBOs vest based upon both the successful achievement of certain corporate operating milestones in specified timelines and continued employment through the applicable vesting date. When the performance goals are deemed to be probable of achievement for these types of awards, recognition of stock-based compensation expense commences. Once the number of shares eligible to vest is determined, those shares vest in two equal installments with 50% vesting upon achievement and the remaining 50% vesting on the first anniversary of achievement, in each case, subject to the recipient’s continued service through the applicable vesting date. If the performance goals are achieved at the threshold level, the number of shares eligible to vest in respect of the PSUs and PBOs would be equal to half the number of PSUs granted and one-quarter the number of shares underlying the PBOs granted. If the performance goals are achieved at the target level, the number of shares eligible to vest in respect of the PSUs and PBOs would be equal to the number of PSUs granted and half of the shares underlying the PBOs granted. If the performance goals are achieved at the superior level, the number of shares eligible to vest in respect of the PSUs would be equal to two times the number of PSUs granted and equal to the number of PBOs granted. The number of shares issuable upon achievement of the performance goals at the levels between the threshold and target levels for the PSUs and PBOs or between the target level and superior levels for the PSUs would be determined using linear interpolation. Achievement below the threshold level would result in no shares being eligible to vest in respect of the PSUs and PBOs.
In the first half of 2020, we awarded PSUs ("2020 PSUs") and PBOs ("2020 PBOs"), each of which commence vesting based upon the achievement of various weighted performance goals, including sustained revenue and performance enzyme growth, strategic advancements of biotherapeutics pipeline, safety and technology development. As of September 30, 2020, we estimated that the 2020 PSUs and 2020 PBOs performance goals would be achieved at 100% of the target level, and recognized expenses accordingly.
In 2019, we awarded PSUs ("2019 PSUs") and PBOs ("2019 PBOs"), each of which commenced vesting based upon the achievement of various weighted performance goals, including sustained revenue and performance enzyme growth, strategic advancement of biotherapeutics, cash balance and strategic plan development. In the first quarter of 2020, we determined that the 2019 PSUs and 2019 PBOs performance goals had been achieved at 106% of the target level, and recognized expenses accordingly. Accordingly, 50% of the shares underlying the 2019 PSUs and PBOs vested in the first quarter of 2020 and 50% of the shares underlying the 2019 PSUs and PBOs will vest in the first quarter of 2021, in each case subject to the recipient’s continued service on each vesting date.
In 2018, we awarded PSUs ("2018 PSUs") and PBOs ("2018 PBOs"), each of which commenced vesting based upon the achievement of various weighted performance goals, including core business revenue growth, cash balance, new licensing collaborations, new research and development service revenue arrangements, technology advancement and novel therapeutic enzymes advancement. In the first quarter of 2019, we determined that the 2018 PSUs and 2018 PBOs performance goals had been achieved at 118% of the target level, and recognized expenses accordingly. Accordingly, 50% of the shares underlying the 2018 PSUs and PBOs vested in the first quarter of 2019 and 50% of the shares underlying the 2018 PSUs and PBOs vested in the first quarter of 2020, in each case subject to the recipient’s continued service on each vesting date.
Stock-Based Compensation Expense
Stock-based compensation expense is included in the unaudited condensed consolidated statements of operations as follows (in thousands):
  Three Months Ended September 30, Nine months ended September 30,
  2020 2019 2020 2019
Research and development $ 385  $ 458  $ 1,279  $ 1,249 
Selling, general and administrative 1,599  1,274  4,813  4,534 
   Total $ 1,984  $ 1,732  $ 6,092  $ 5,783 

The following table presents total stock-based compensation expense by security type included in the unaudited condensed consolidated statements of operations for the three and nine months ended September 30, 2020 and 2019 (in thousands):
  Three Months Ended September 30, Nine months ended September 30,
  2020 2019 2020 2019
Stock options $ 619  $ 545  $ 1,735  $ 1,680 
RSUs and RSAs 603  461  1,812  1,308 
PSUs 295  368  922  1,075 
PBOs 467  358  1,623  1,720 
   Total $ 1,984  $ 1,732  $ 6,092  $ 5,783 

In June 2020, we granted an option to purchase 60,000 shares of common stock to a non-employee as compensation for services. The estimated fair value of the grant was valued at $0.3 million using the Black-Scholes-Merton option pricing model with the following assumptions used to estimate the fair value of non-employee stock options: (i) volatility rate at 51.9%, (ii) risk-free interest rate of 0.4% and (iii) no expected dividend yield. The option vests over 2 years from the date of grant with 50% vesting after one year and the remaining 50% vesting monthly in the second year. In August 2020, we granted an option to purchase 16,000 shares of common stock to a non-employee as compensation for services. The estimated fair value of the grant was valued at $0.1 million using the Black-Scholes-Merton option pricing model with the following assumptions used to estimate the fair value of non-employee stock options: (i) volatility rate at 50.5%, (ii) risk-free interest rate of 0.3% and (iii) no expected dividend yield. The option vests over 1 year with 100% on the first anniversary of the grant date. We recognized stock-based compensation expense related to the non-employees of $43 thousand and $47 thousand for the three and nine months ended September 30, 2020, respectively.
As of September 30, 2020, unrecognized stock-based compensation expense, net of expected forfeitures, was $4.2 million related to unvested employee stock options, $0.3 million related to unvested non-employee stock options, $2.3 million related to unvested RSUs and RSAs, $0.8 million related to unvested PSUs, and $1.3 million related to unvested PBOs based on current estimates of the level of achievement. Stock-based compensation expense for these awards will be recognized through the year of 2024.