Annual report pursuant to Section 13 and 15(d)

Consolidated Statements of Operations (Parenthetical)

v3.20.1
Consolidated Statements of Operations (Parenthetical) - USD ($)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Stock-based compensation expense $ 1,446,549 $ 1,555,523 $ 1,623,128
Research and Development Expense [Member]      
Stock-based compensation expense 469,357 626,002 451,334
General and Administrative Expense [Member]      
Stock-based compensation expense $ 977,192 $ 929,521 $ 1,171,794