Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses (Details) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Accrued Liabilities And Other Liabilities [Abstract]
Accrued research and development	$ 1,962,691	$ 4,293,522
Accrued compensation	3,056,345	2,870,261
Accrued general and administrative	5,044,886	1,155,508
Accrued interest	381,250	393,958
Total	$ 10,445,172	$ 8,713,249