As of September 30, 2021, we had $44,357,000 of unrecognized compensation expense related to employee stock options that are expected to vest over a period of 2.61 years. As of September 30, 2020, we had $33,036,000 of unrecognized compensation expense related to employee stock options that are expected to vest over a period of 2.85 years.
Restricted Stock Unit Activity
For the three months ended September 30, 2021 and September 30, 2020, stock-based compensation for restricted stock unit grants was $72,000 and $53,000, respectively. For the three months ended September 30, 2021, the expenses were recorded as $63,000 in research and development expense and $9,000 in selling, general, and administrative expense. For the three months ended September 30, 2020, the expenses were recorded as $48,000 in research and development expense and $5,000 in selling, general, and administrative expense.
For the nine months ended September 30, 2021 and September 30, 2020, stock-based compensation for restricted stock unit grants was $217,000 and $123,000, respectively. For the nine months ended September 30, 2021, the expenses were recorded as $194,000 in research and development expense and $23,000 in selling, general, and administrative expense. For the nine months ended September 30, 2020, the expenses were recorded as $112,000 in research and development expense and $11,000 in selling, general, and administrative expense.
The following table summarizes restricted stock units issued and outstanding:
| | | | | | | | |
| | | | | | | Weighted | |
| | | | Weighted | | average | |
| | | | average | | remaining | |
| | | | grant | | vesting | |
| | Restricted Stock Units | | price | | life (years) | |
Outstanding and expected to vest at December 31, 2020 | | 30,146 | | $ | 25.45 | | 2.18 | |
Granted | | 10,092 | | | 33.86 | | | |
Vested | | (10,099) | | | 22.76 | | | |
Forfeited | | (3,367) | | | 26.33 | | | |
Outstanding and expected to vest at September 30, 2021 | | 26,772 | | $ | 29.53 | | 1.91 | |
As of September 30, 2021, we had $631,000 of unrecognized compensation related to employee restricted stock units that are expected to vest over a period of 1.91 years. As of September 30, 2020, we had $524,000 of unrecognized compensation related to employee restricted stock units that are expected to vest over a period of 2.40 years.
NOTE 11—RELATED PARTY TRANSACTIONS
MSK is a shareholder of the Company. Under the MSK License Agreement, the SADA License Agreement, the CD33 License Agreement, and various other supporting agreements with MSK, we have expensed costs in the total amount of $1,154,000 and $1,050,000 in the three months ended September 30, 2021 and 2020, respectively, for milestones, minimum royalties, and research and development costs. We expensed costs in the total amounts of $3,259,000 and $7,626,000 in the nine months ended September 30, 2021 and 2020, respectively, under these agreements with MSK. Please refer to Note 8—License Agreements and Commitments for additional details on our agreements with MSK. As of September 30, 2021, we had a total of $472,000 recorded as accounts payable, $4,804,000 as accrued liabilities, thereby totaling $5,276,000 due to MSK. As of December 31, 2020, we had a total of $833,000 recorded as accounts payable, $7,161,000 as accrued liabilities, thereby totaling $7,994,000 due to MSK.
NOTE 12—INCOME TAXES
The Company provided 0 current and deferred income taxes on net losses of $28,858,000 and $32,832,000 for the three month periods ended September 30, 2021 and 2020, respectively, and the net loss of $18,382,000 and $99,404,000 for the nine month periods ended September 30, 2021 and 2020, respectively.