For the years ended December 31, 2022, the decrease in costs related to other programs compared to the year ended December 31, 2021, was negligible.
For the year ended December 31, 2022, the decrease in unallocated costs of $3.0 million as compared to the year ended December 31, 2021, primarily consisted of a decrease of $3.1 million in personnel and related costs and a a decrease of $0.3 million in facility related costs, partially offset by an increase of $0.4 million in outside services.
For the year ended December 31, 2021, the decrease in CPI-818 costs of $1.8 million as compared to the year ended December 31, 2020, primarily consisted of a decrease of $1.0 million in clinical trial expenses, a decrease of $0.1 million in other outside services and a decrease of $0.1 million in drug manufacturing costs. Additionally, $0.6 million in drug manufacturing costs, which were expensed in prior years, were billed to Angel Pharmaceuticals during the year ended December 31, 2021.
For the year ended December 31, 2021, the decrease in ciforadenant costs of $2.3 million as compared to the year ended December 31, 2020, primarily consisted of a decrease of $1.9 million in clinical trial expenses and a decrease of $0.5 million in other outside services, partially offset by an increase of $0.1 million in drug manufacturing costs.
For the year ended December 31, 2021, the increase in mupadolimab costs of $5.2 million as compared to the year ended December 31, 2020, primarily consisted of an increase of $3.1 million in clinical trial expenses, an increase of $1.8 million in drug manufacturing costs as well as an increase of $0.3 million in other outside services.
For the year ended December 31, 2021, the decrease in costs related to other programs of $0.6 million as compared to the year ended December 31, 2020, primarily consisted of a decrease of $0.5 million in manufacturing costs and a decrease of $0.1 million in other outside services.
For the year ended December 31, 2021, the decrease in unallocated costs of $3.3 million as compared to the year ended December 31, 2020, primarily consisted of a decrease of $2.7 million in personnel and related costs and a decrease of $0.6 million in outside services.
General and Administrative Expenses
For the year ended December 31, 2022, the decrease in general and administrative expenses of $1.4 million as compared to the year ended December 31, 2021, primarily consisted of a decrease in personnel and related costs.
For the year ended December 31, 2021, the decrease in general and administrative expenses of $2.4 million as compared to the year ended December 31, 2020, primarily consisted of a decrease of $1.3 million in outside professional services and a decrease of $1.1 million in personnel and related costs.
Interest Income and Other Expense, net
For the year ended December 31, 2022, the increase in interest income and other expense, net of $0.7 million as compared to the year ended December 31, 2021, primarily consisted of an increase in interest income earned due to an increase in interest rates.
For the year ended December 31, 2021, the decrease in interest income and other expense, net of $0.6 million as compared to the year ended December 31, 2020, primarily consisted of a decrease in interest income earned due to a decrease in interest rates.
Gain from sale of property and equipment
For the year ended December 31, 2022, the gain from sale of property and equipment consisted of proceeds from the sale of laboratory equipment.