December 31, 2017 | December 31, 2016 | December 31, 2015 | ||||||
Pre-clinical projects | 642,821 | 546,429 | 468,326 | |||||
Clinical projects | 12,365,768 | 16,639,304 | 20,808,025 | |||||
Drug manufacturing and substance | 2,027,184 | 2,608,814 | 1,866,148 | |||||
Employee benefits and expenses | 2,773,516 | 2,854,624 | 2,140,664 | |||||
Lease expenses | 111,680 | 84,344 | 42,953 | |||||
Patents and trademarks | 603,892 | 941,836 | 824,201 | |||||
Regulatory projects | 632,387 | 1,043,287 | 331,822 | |||||
Depreciation tangible assets | 53,594 | 58,125 | 54,037 | |||||
Total research and development expense | 19,210,842 | 24,776,763 | 26,536,176 | |||||