Nature of Operations and Basis of Presentation - Schedule of Effect of Error Correction on Previously Issued Financial Statements (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Changes in the balance sheet:
Deferred collaboration funding, short-term	$ 19,016,258
Total current liabilities	32,335,929		$ 6,145,546
Other non-current liabilities	4,863,457		243,808
Total liabilities	37,199,386		6,389,354
Accumulated deficit	(103,747,266)		(99,135,961)
Total stockholders' equity	7,311,512	$ 14,088,948	$ 8,224,334	$ 18,370,316
Changes in the statement of operations:
Revenue	900,000
Loss from operations	(4,620,046)	(4,971,456)
Net loss	$ (4,611,305)	$ (4,948,707)
Net loss per share - basic and diluted	$ (0.33)	$ (0.49)
Changes in the statement of cash flows:
Net loss	$ (4,611,305)	$ (4,948,707)
Deferred collaboration funding, short-term and long-term	19,813,897
As Previously Reported
Changes in the balance sheet:
Deferred collaboration funding, short-term	20,715,764
Total current liabilities	34,035,435
Other non-current liabilities	65,818
Total liabilities	34,101,253
Accumulated deficit	(100,649,133)
Total stockholders' equity	10,409,645
Changes in the statement of operations:
Revenue	3,998,133
Loss from operations	(1,521,913)
Net loss	$ (1,513,172)
Net loss per share - basic and diluted	$ (0.11)
Changes in the statement of cash flows:
Net loss	$ (1,513,172)
Deferred collaboration funding, short-term and long-term	16,715,764
Correction of Error
Changes in the balance sheet:
Deferred collaboration funding, short-term	(1,699,506)
Total current liabilities	(1,699,506)
Other non-current liabilities	4,797,639
Total liabilities	3,098,133
Accumulated deficit	(3,098,133)
Total stockholders' equity	(3,098,133)
Changes in the statement of operations:
Revenue	(3,098,133)
Loss from operations	(3,098,133)
Net loss	$ (3,098,133)
Net loss per share - basic and diluted	$ (0.22)
Changes in the statement of cash flows:
Net loss	$ (3,098,133)
Deferred collaboration funding, short-term and long-term	$ 3,098,133