78 Components of Operating Results Research and Developm o ent Expe x nses Subs u tantially all of our research and development expenses consist of expenses incurred in connection with the development of our product candidates and ABC Platform. These expenses include certain payroll and personnel expenses, including stock-based compensation, for our research and product development employees; labor a atory r suppl u ies and facility costs; consulting costs; contract manufact f ur t ing and fees paid to CROs to conduct certain research and development activities on our behalf;f and allocated overhead, including rent, equipment, depreciation and utilities. We expense both internal and external research and development expenses as they are incurred. Costs of certain activities, such as manufact f ur t ing and preclinical and clinical studi t es, are generally recognized based on an evaluation of the progress to completion of specific tasks. Nonrefunda f bl a e payments made prior to the receipt of goods or services that will be used or rendered for future research and development activities are deferred and capitalized. The capitalized amounts are recognized as expense as the goods are delivered or the related services are performed. We are focusing subs u tantially all of our resources and development effo f rts on the development of our product candidates. Predicting the timing or the final cost to complete our clinical program or validation of our commercial manufac f turing and suppl u y processes is difficult and delays may occur because of many factors, including factors outside of our control. For example, if the FDA or other regulatory r authorities were to require us to conduct clinical trials beyond those that we currently anticipate, or if we experience significant delays in enrollment in any of our clinical trials, we could be required to expend significant additional financial resources and time on the completion of clinical development. Furthermore, we are unabl a e to predict when or if our drug r candidates will receive regulatory r approval with any certainty. General and Admi d nist i rative Expe x nses General and administrative expenses consist principally of payroll and personnel expenses, including stock-based compensation; profes f sional fees for legal, consulting, accounting and tax services; compliance costs associated with being a public company; allocated overhead, including rent, equipment, depreciation and utilities; and other general operating expenses not otherwise classified as research and development expenses. Interest Income Interest income consists primarily of interest income earned on our cash, cash equivalents and marketable securities. Other Income (Exp E ense), e Net Other income (expense), net consists primarily of the change in fair value and settlement of derivative contracts, tax expense and the amortized issuance costs from the liabi a lity related to the future sale of royalties to Baker Bros. Advisors, LP ("BBA") in 2019. Results of Operations The following tabl a e summarizes the results of our operations for the periods indicated (in thousands, except percentages): Year Ended December 31, Change 2023 2022 Dollar Percent Operating expenses Research and development $ 206,298 $ 267,591 $ (61,293) (23%) General and administrative 71,023 73,788 (2,765) (4%) Loss from operations (277,321) (341,379) 64,058 (19%) Interest income 16,733 7,071 9,662 137% Interest expense (13) (18) 5 * Other income (expense), net 110 503 (393) * Net loss $ (260,491) $ (333,823) $ 73,332 (22%) * Change is not meaningful f Research and Developm o ent Expe x nses Research and development expenses decreased $61.3 million, or 23%, during the year ended December 31, 2023 as compared to 2022.