Research and development expenses: In the fourth quarter of 2024, research and development expenses were $3.8 million, compared to $2.0 million in the fourth quarter of 2023. Research and development expenses for full year 2024 were $12.6 million, compared to $93.2 million for full year 2023, which included an $81.5 million IPR&D expense related to the acquisition of a North American license for AGAMREE in the third quarter of 2023.
Selling, general, and administrative expenses: Selling, general, and administrative expenses for the fourth quarter of 2024 were $44.2 million, compared to $42.0 million in the fourth quarter of 2023. Selling, general, and administrative expenses for full year 2024 were $177.7 million, compared to $133.7 million for full year 2023.
Amortization of intangible assets: Amortization of intangible assets was $9.3 million in the fourth quarter of 2024, compared to $9.1 million in the fourth quarter of 2023. Amortization of intangible assets was $37.4 million in full year 2024, compared to $32.6 million for full year 2023.
Operating income: Operating income for the fourth quarter of 2024 was $62.8 million, compared to $41.7 million in the fourth quarter of 2023, representing an increase of approximately 50.7%. Full year 2024 operating income was $195.1 million, compared to $86.8 million for full year 2023, representing an increase of approximately 124.8%.
GAAP net income: GAAP net income for the fourth quarter of 2024 was $55.9 million ($0.47 per basic and $0.44 per diluted share), compared to GAAP net income of $34.8 million ($0.33 per basic and $0.31 per diluted share) for the fourth quarter of 2023. GAAP net income for full year 2024 was $163.9 million ($1.38 per basic and $1.31 per diluted share), compared to full year 2023 GAAP net income of $71.4 million ($0.67 per basic and $0.63 per diluted share).
Non-GAAP net income: Non-GAAP net income for the fourth quarter of 2024 was $88.8 million ($ 0.74 per basic and $0.70 per diluted share), compared to non-GAAP net income of $60.1 million ($0.56 per basic and $0.53 per diluted share) for the fourth quarter of 2023. Non-GAAP net income for full year 2024 was $276.3 million ($2.33 per basic and $2.21 per diluted share), compared to full year 2023 non-GAAP net income of $141.6 million ($1.33 per basic and $1.25 per diluted share). Non-GAAP net income in all periods excludes from net income stock-based compensation, depreciation, amortization of intangible assets, and the income tax provision.
Cash and cash equivalents: Cash and cash equivalents were $517.6 million as of December 31, 2024.
More detailed financial information and analysis of our financial condition and results of operations can be found in our Annual Report on Form 10-K for fiscal year 2024, which was filed with the U.S. Securities and Exchange Commission on February 26, 2025.
2025 Outlook
For full year 2025, the Company expects total revenues to be between $545 million and $565 million, reflecting continued growth in product revenue, net from FIRDAPSE and AGAMREE.