timing of the activities related to our pivotal and pediatric trials, and an increase in general research and development costs of approximately $1,677,000 primarily attributable to increased personnel-related costs.
General and Administrative. General and administrative expenses for the year ended December 31, 2023, were approximately $11,694,000, compared to approximately $10,548,000 in 2022. The increase of $1,146,000, or 11% in general and administrative costs was primarily driven by an increase in personnel costs partially offset by a reduction in professional fees.
Other income (expense), net. Other income (expense), net for 2023 was an expense of approximately $3,870,000, as compared to approximately $3,039,000 of expense in 2022. The decrease was largely a result of the cost of the September 2023 financing being substantially lower than that of the October 2022 financing, partially offset by the impact of the warrant revaluation having an unfavorable impact in 2023, whereas in 2022 the impact was favorable. Interest income, net, improved to approximately $387,000 in 2023 as compared to approximately $153,000 in 2022. The increase in interest earned is a result of higher interest rates supporting stronger returns on money market cash equivalents coupled with higher average balances of cash on hand in 2023.
Liquidity and Capital Resources
Year Ended December 31, 2023, Compared to Year Ended December 31, 2022
As of December 31, 2023, we had cash and cash equivalents of $9.6 million, compared to $19.9 million as of December 31, 2022, a decrease of $10.3 million. This decrease was primarily a result of increased research and development expenses and general and administrative expenses, partially offset by funds raised through equity securities. The cash used in operating activities during the twelve months ended December 31, 2023, was approximately $32,377,000.
Investing activities consist exclusively of fixed asset purchases. The increase in 2023 over 2022 relates to development of the infrastructure necessary to support our manufacturing capabilities, particularly ensuring that we have redundancy in each aspect of the supply chain to eliminate disruptions to product availability upon commercialization.
Net cash proceeds from the issuance of common stock, preferred stock, warrants, and the exercise of warrants by investors during 2023 was approximately $22,940,000, as compared to approximately $9,611,000 for similar financing activities in 2022.
Our cash requirements have historically been for our research and development activities, finance and administrative costs, capital expenditures and overall working capital. We have experienced negative operating cash flows since inception and have funded our operations primarily from sales of common stock and other securities. As of December 31, 2023, we had an accumulated deficit of approximately $202,761,000.
Nine Months Ended September 30, 2024, Compared to Nine Months Ended September 30, 2023
As of September 30, 2024, we had cash and cash equivalents of $34.3 million, compared to $19.0 million as of September 30, 2023, an increase of $15.3 million. This increase was primarily a result of funds raised through the sale of equity securities and the exercise of outstanding warrants by investors, partially offset by research and development expenses and general and administrative expenses. The cash used in operating activities during the nine months ended September 30, 2024, was approximately $36,670,000.
Investing activities consist exclusively of fixed asset purchases. The decrease in 2024 from 2023 relates to the development of the infrastructure necessary to support our manufacturing capabilities during 2023, an effort that did not recur in 2024.
Net cash proceeds from the issuance of common stock, preferred stock, warrants, and the exercise of warrants by investors during the nine months ended September 30, 2024, was approximately $61,411,000, as compared to approximately $22,499,000 for such activities in the comparable period in 2023.
Our cash requirements have historically been for our research and development activities, finance and administrative costs, capital expenditures and overall working capital. We have experienced negative operating cash flows since inception and have funded our operations primarily from sales of common stock and other securities. As of September 30, 2024, we had an accumulated deficit of approximately $244,987,000.