Research
Research includes expenses to evaluate new targets and to develop and evaluate new antibodies, linkers, and cytotoxic agents. Such expenses include third-party license fees, research funding payments, and contract services. In the three months ended September 30, 2023, research expenses increased by $0.8 million driven largely by greater activity under our research collaboration agreement with Oxford BioTherapeutics Ltd. (OBT) as compared to the prior period. Driving the $4.2 million decrease in research expenses for the nine months ended September 30, 2023, during the prior year period, we recorded a $7.5 million upfront license fee paid pursuant to the OBT agreement as expense. Partially offsetting this expense, during the nine months ended September 30, 2023, we recorded greater committed research costs related to the agreement with OBT.
Preclinical and clinical testing
Preclinical and clinical testing includes expenses related to preclinical testing of our own, and, in certain instances, our collaborators’ product candidates, regulatory activities, the cost of clinical trials, and expenses related to medical affairs. Such expenses include the costs of personnel, third-party staffing, patient enrollment at our clinical testing sites, consultant fees, contract services, and facility expenses. In the three months ended September 30, 2023, preclinical and clinical testing expenses decreased by $2.2 million compared to the three months ended September 30, 2022, due primarily to lower hiring costs, a decrease in clinical trial costs driven by the winding down of the SORAYA and MIRASOL trials, and greater co-development reimbursement from MacroGenics, partially offset by increased salaries and benefit expenses resulting from an expanded medical affairs team to support the advancement of ELAHERE. For the nine months ended September 30, 2023, preclinical and clinical testing expenses increased by $11.7 million compared to the nine months ended September 30, 2022, due primarily to greater salaries and benefit expenses and an increase in clinical trial costs driven by our ELAHERE label expansion, PVEK, and IMGN151 trials, partially offset by lower hiring costs.
Process and product development
Process and product development expenses include costs for development of clinical and commercial manufacturing processes for our own and collaborator compounds. Such expenses include the costs of personnel, third-party staffing, contract services, and facility expenses. In the three and nine months ended September 30, 2023, process and product development expenses increased by $0.7 million and $2.2 million, respectively, compared to the three and nine months ended September 30, 2022, due primarily to increased salaries and benefit expenses and third-party contract services related to advancing early-stage programs.
Manufacturing operations
Manufacturing operations expense includes costs to have preclinical and clinical materials manufactured for our product candidates and quality control and quality assurance activities. Such expenses include personnel, third-party staffing, raw materials for our preclinical studies and clinical trials, non-pivotal and pivotal development costs with contract manufacturing organizations, and facility expenses. In the three and nine months ended September 30, 2023, manufacturing operations expense decreased by $10.9 million and $15.2 million, respectively, compared to the three and nine months ended September 30, 2022, due primarily to raw materials produced for use in the manufacture and sale of ELAHERE in the prior year periods, which were expensed where produced prior to FDA accelerated approval but are now capitalized as inventory, partially offset by increases in salaries and benefit expenses.
Selling, general and administrative expenses
Selling, general and administrative expenses consist primarily of personnel-related costs, including stock-based compensation, for commercial operations and for personnel in executive, finance, accounting, business development, information technology, legal, and human resources functions. Other significant costs include facility costs not otherwise included in research and development expenses, commercial development activities, legal fees related to intellectual property and corporate matters, and fees for accounting and consulting services.
In the three and nine months ended September 30, 2023, selling, general and administrative expenses increased by $4.1 million and $40.1 million, respectively compared to the three and nine months ended September 30, 2022 due to greater expenses in support of advancing the U.S. launch of ELAHERE, including salaries and benefit expenses, infrastructure costs, and sales and marketing activities.