Basic loss per common share is computed by dividing net loss by the weighted average number of common shares outstanding during the reporting period. Diluted loss per common share is computed similar to basic loss per common share except that it reflects the potential dilution that could occur if dilutive securities or other obligations to issue common stock were exercised or converted into common stock. The pre-funded warrants, described in Note 12 below, are issuable for nominal consideration of $0.01 per share, are immediately exercisable and do not expire. As such, the shares of common stock issuable upon full exercise of the pre-funded warrants (for cash) are considered outstanding in the context of loss per share, as required by ASC 260‑10‑45-13, and are included in the weighted-average number of common shares outstanding from their issuance date.

The following table provides the numerator and denominator used in computing basic and diluted net loss per share for the periods indicated:

	Three Months Ended September 30,							Nine Months Ended September 30,
	2019			2018			2019				2018
Numerator:
Net loss	$	(4,740,232	)	$	(4,843,408	)	$		(14,908,348	)	$	(14,326,084	)
Denominator:
Weighted-average shares outstanding-basic and diluted		31,367,044			28,434,406				29,551,836			27,184,968
Net loss per share, basic and diluted	$	(0.15	)	$	(0.17	)	$		(0.50	)	$	(0.53	)

The following outstanding securities were excluded from the computation of diluted net loss per share for the periods presented because their effect would have been anti-dilutive:

	Nine Months Ended September 30,
	2019		2018
Options to purchase common stock		2,940,990		2,148,323
Common stock warrants		236,915		237,846
Restricted stock units		247,079		249,166
QNAH convertible note		794,665		772,075