| Schedule of Expenses by Segment |
In addition, research and development and selling, general and administrative expenses are significant segment expenses regularly provided to the CEO with the following categories: Research and Development | | | | | | | | | | | | | | | | | | | | | | | Years Ended December 31, | (In thousands) | | 2025 | | 2024 | | 2023 | | Clinical research and outside services | | $ | 640,672 | | | $ | 509,129 | | | $ | 485,732 | | | Compensation and related | | 516,208 | | | 455,678 | | | 357,696 | | Occupancy and all other costs(1) | | 162,895 | | | 161,425 | | | 160,987 | | Total research and development expense | | $ | 1,319,775 | | | $ | 1,126,232 | | | $ | 1,004,415 | |
Selling, General and Administrative | | | | | | | | | | | | | | | | | | | | | | | Years Ended December 31, | (In thousands) | | 2025 | | 2024 | | 2023 | Compensation and related | | $ | 668,302 | | | $ | 531,078 | | | $ | 423,295 | | Consulting and professional services | | 348,976 | | | 274,539 | | | 226,664 | | Occupancy and all other costs(1) | | 193,435 | | | 169,909 | | | 145,687 | | Total selling, general and administrative expense | | $ | 1,210,713 | | | $ | 975,526 | | | $ | 795,646 | |
(1) Occupancy and all other costs includes facilities, information technology, depreciation and certain departmental expenses. |