|PACIRA PHARMACEUTICALS, INC. filed this Form 10-K on 03/01/2017|
condition of FDA approval or are conducted to generate new data such as dosing and administration techniques. Clinical trial expenses include costs for clinical personnel, services performed by third-party contract research organizations, materials and supplies, database management and other third-party fees. Product development and other expenses include development costs for our pipeline products and medical information expenses, which include personnel, equipment, materials and contractor costs for both new process development and new product candidates, toxicology studies and facility costs for our research space. Stock-based compensation expense relates to the costs of stock option grants to employees and non-employees, awards of restricted stock units, or RSUs, and our employee stock purchase plan, or ESPP.
The following table provides a breakout of our research and development expenses during the periods indicated, including percent changes (dollar amounts in thousands):
Total research and development expenses increased 59% in 2016 versus 2015 largely due to an $11.0 million increase in clinical development expenses driven by the enrollment of the Phase 4 infiltration trial in TKA and two Phase 3 nerve block trials, including a femoral nerve block in subjects undergoing TKA and a brachial plexus block in patients undergoing total shoulder arthroplasty, or rotator cuff repair procedures. We also incurred start-up expenses in our spine trial and costs for planning pediatric trials. Increased costs also include a larger clinical workforce, which is managing our increasing investment in research and development initiatives. The increase in clinical development expense was partially offset by a decrease in research grants. Product development and other expenses increased $7.9 million which reflects our investments in the development of a new EXPAREL DepoFoam spray manufacturing process, DepoMLX and DepoTXA, the latter of which is now in Phase 2 clinical development, along with increased depreciation on our new research and development facility placed into service in August 2015. Expenses for investigational runs and development of a new analytical test for the stability testing attribute are also included in costs for product development and other. Stock-based compensation decreased 36%, which was largely attributable to the requirement to revalue non-employee grants.
Total research and development expenses increased 53% in 2015 versus 2014 driven by a $7.1 million increase in clinical development, including the initiation of and enrollment in our Phase 4 trial in third molar procedures, start-up expenses for our Phase 4 infiltration trial in TKA, two Phase 3 trials in nerve block procedures which began in 2015, and Phase 4 trials in tonsillectomy and C-section. Product development and other increased $4.2 million, reflecting our investments in the development of a new EXPAREL DepoFoam spray manufacturing process, DepoTXA, DepoMLX and additional pre-clinical expenses driven by DepoFoam toxicology trials. Stock-based compensation decreased 21%, which was largely attributable to the requirement to revalue non-employee grants.
Selling, General and Administrative Expenses
Sales and marketing expenses primarily consist of compensation and benefits for our sales force and personnel that support our sales, marketing, medical and scientific affairs operations, commission payments to our marketing partners for the promotion and sale of EXPAREL, expenses related to communicating health outcome benefits of EXPAREL patients and educational programs for our customers. General and administrative expenses consist of compensation and benefits for legal, finance, regulatory, compliance, information technology, human resources, executive management and other supporting personnel. It also includes professional fees for legal, audit, tax and consulting services. Stock-based compensation expense relates to the costs of stock option grants, RSU awards and our ESPP.
The following table provides information regarding selling, general and administrative expenses during the periods indicated, including percent changes (dollar amounts in thousands):