Full Year 2023 Financial Results Compared to Prior Year Period
Research and development expenses increased $1.4 million, or 3.1%, compared to year ended December 31, 2022. Salaries, benefits, and other personnel costs increased $2.8 million due to an increase in the hiring of employees to support the growth in the Company's development activities, and to a lesser extent, increases in salaries of our continuing employees. These increases were offset by less expenses incurred related to preclinical research programs for the comparable period.
SG&A expenses decreased $7.6 million, or 15.8%, compared to the year ended December 31, 2022. This decrease was primarily driven by a reduction in professional fees of $6.5 million, due to decreased legal fees associated with certain litigation matters, and $0.7 million decreased insurance-related premiums.
Total revenues decreased $20.7 million, or 76.9%, compared to the year ended December 31, 2022. Collaboration and licensing revenues decreased $14.6 million, or 99.5%, compared to the year ended December 31, 2022, primarily due to the prior year period non-cash recognition of revenue related to historical collaboration agreements for which revenue was previously deferred. Product and services revenues decreased $5.9 million, or 48.8%, compared to the year ended December 31, 2022. This decrease is related to reductions in services performed at Exemplar as well as the recognition of revenue in the first quarter of 2022 related to agreements for which revenue was previously deferred that did not occur in 2023.
Total other income, net, increased $8.5 million, compared to the year ended December 31, 2022. This was primarily due to $6.3 million in reduced interest expense associated with the Convertible Notes as they were fully retired in the second quarter of 2023, and $3.1 million increased interest income due to higher interest rates on investments. This increase was partially offset by a $0.9 million decrease in gain recorded on the early retirement of a portion of our Convertible Notes compared to the year ended December 31, 2022.
The Company recorded a $10.4 million impairment charge in the fourth quarter of 2023 related to its Exemplar subsidiary as a result of the Company's annual goodwill impairment test.
Loss from continuing operations was $95.9 million, or $(0.39) per basic and diluted share, compared to loss from continuing operations of $79.8 million, or $(0.40) per basic and diluted share, in year ended December 31, 2022.