Common Stock Warrants and Common Stock Warrant Liability (Tables)

3 Months Ended

Mar. 31, 2019

Warrants and Rights Note Disclosure [Abstract]

Schedule of common stock warrant activity

The table summarizes the common stock warrant activity as of March 31, 2019 as follows:

Common Stock Warrants	Number of Warrants			Date  Issued	Term		Exercise Price
Outstanding at December 31, 2017		6,431,785
Warrants issued		1,133,909		June 2018		5 Years	$	1.82
Common Stock Offering Warrants Issued		5,357,052		August 2018		5 Years	$	1.15	(1)
Common Stock Offering - Dealer Manager Warrants		267,853		August 2018		5 Years	$	1.725
Warrants exercised		(1,475,659	)
Expired Warrants		(488,119	)
Outstanding at December 31, 2018		11,226,821
Warrants Exercised		(31,811	)	August 2018			$	1.15
Outstanding at March 31, 2019		11,195,010

(1) The common stock warrants issued in November 2017 with an initial exercise price of $1.50 per share adjusted downward to $0.95 per share effective July 24, 2018 in connection with our Rights Offering, and may be subject to further downward adjustments, pursuant to antidilution price adjustment protection contained within those warrants.