Research and Development Expense
Research and development expenses consist primarily of (i) personnel expenses, (ii) laboratory supply expenses relating to the development of our technology, (iii) facility expenses and (iv) product development expenses associated with our drug candidates as follows:
| | | | | | | | | | | | |
| | Nine Months Ended | | Increase/ | |
| | September 30, | | (Decrease) | |
| | 2023 | | 2022 | | $ | | % | |
|
| | (In thousands) | |
Personnel | | $ | 28,559 | | $ | 24,116 | | $ | 4,443 | | 18 | % |
Laboratory supplies | | | 4,167 | | | 4,821 | | | (654) | | (14) | % |
Facility | | | 3,699 | | | 3,566 | | | 133 | | 4 | % |
Product development | | | 45,348 | | | 22,374 | | | 22,974 | | 103 | % |
Personnel expenses primarily include salary, benefits, stock-based compensation and payroll taxes. The $4.4 million increase in personnel expenses for the nine months ended September 30, 2023, as compared to the nine months ended September 30, 2022, was primarily due to higher stock-based compensation expense and an increase in employee headcount.
Laboratory supplies expenses include laboratory materials and supplies, services, and other related expenses incurred in the development of our technology. The $0.7 million decrease in laboratory supply expenses for the nine months ended September 30, 2023, as compared to the nine months ended September 30, 2022, was primarily due to lower laboratory materials and supplies purchases.
Facility expenses include depreciation, amortization, utilities, rent, maintenance and other related expenses incurred at our facilities. The $0.1 million increase in facility expenses for the nine months ended September 30, 2023, as compared to the nine months ended September 30, 2022, was primarily due to higher repairs expense.
Product development expenses include clinical investigator site fees, external trial monitoring costs, data accumulation costs, contracted research and outside clinical drug product manufacturing. The $23.0 million increase in product development expenses for the nine months ended September 30, 2023, as compared to the nine months ended September 30, 2022, was primarily due to an increase in barzolvolimab clinical trial and contract manufacturing expenses.
General and Administrative Expense
The $1.5 million increase in general and administrative expenses for the nine months ended September 30, 2023, as compared to the nine months ended September 30, 2022, was primarily due to an increase in stock-based compensation and recruiting expenses, partially offset by a decrease in legal expenses.
Gain on Fair Value Remeasurement of Contingent Consideration
The $6.9 million gain on fair value remeasurement of contingent consideration for the nine months ended September 30, 2022 was primarily due to our decision to deprioritize the CDX-1140 program.
Litigation Settlement Related Loss
We recorded a loss of $15.0 million in the second quarter of 2022 related to the Initial Payment due under the Term Sheet entered with SRS.
Investment and Other Income, Net
The $7.3 million increase in investment and other income, net for the nine months ended September 30, 2023, as compared to the nine months ended September 30, 2022, was primarily due to higher interest rates on fixed income investments and higher other income related to our sale of New Jersey tax benefits.