Stockholders' Equity

Equity Issuances

Purchase Agreement

In March 2019, the Company and Lincoln Park Capital Fund, LLC (“Lincoln Park”) entered into a purchase agreement (the “Purchase Agreement”) and a registration rights agreement (the “Registration Rights Agreement”), pursuant to which the Company has the right to sell to Lincoln Park shares of the Company’s common stock having an aggregate value of up to $26.0 million, subject to certain limitations and conditions set forth in the Purchase Agreement (the “Offering”). As consideration for entering into the Purchase Agreement, the Company issued to Lincoln Park an additional 181,510 shares of common stock as commitment shares.

Pursuant to the Purchase Agreement, Lincoln Park purchased 250,000 shares of common stock, at a price of $4.00 per share, for a total gross purchase price of $1.0 million (the “Initial Purchase”) upon commencement. Thereafter, as often as every business day from and after one business day following the date of the Initial Purchase and over the 36-month term of the Purchase Agreement the Company has the right, from time to time, at its sole discretion and subject to certain conditions, to direct Lincoln Park to purchase up to 100,000 shares of common stock, with such amount increasing as the closing sale price of the common stock increases; provided Lincoln Park’s obligation under any single such purchase will not exceed $2.5 million, unless the Company and Lincoln Park mutually agree to increase the maximum amount of such single purchase (each, a “Regular Purchase”). If the Company directs Lincoln Park to purchase the maximum number of shares of common stock it then may sell in a Regular Purchase, then in addition to such Regular Purchase, and subject to certain conditions and limitations in the Purchase Agreement, the Company may direct Lincoln Park in an “accelerated purchase” to purchase an additional amount of common stock that may not exceed the lesser of (i) 300% the number of shares purchased pursuant to the corresponding Regular Purchase or (ii) 30% of the total number of shares of the Company’s common stock traded during a specified period on the applicable purchase date as set forth in the Purchase Agreement. Under certain circumstances and in accordance with the Purchase Agreement, the Company may direct Lincoln Park to purchase shares in multiple accelerated purchases on the same trading day.

The Company controls the timing and amount of any sales of its common stock to Lincoln Park. There is no upper limit on the price per share that Lincoln Park must pay for its common stock under the Purchase Agreement, but in no event will shares be sold to Lincoln Park on a day the closing price is less than the floor price specified in the Purchase Agreement. In all instances, the Company may not sell shares of its common stock to Lincoln Park under the purchase agreement if it would result in Lincoln Park beneficially owning more than 9.99% of its common stock.

The Purchase Agreement does not limit the Company’s ability to raise capital from other sources at the Company’s sole discretion, except that (subject to certain exceptions) the Company may not enter into any Variable Rate Transaction (as defined in the Purchase Agreement, including the issuance of any floating conversion rate or variable priced equity-like securities) during the 36 months after the date of the Purchase Agreement. The Company has the right to terminate the Purchase Agreement at any time, at no cost to the Company.

Common Stock Sales Agreement

In February 2018, the Company entered into a common stock sales agreement (the "Sales Agreement") with H.C. Wainwright & Co., LLC ("HCW") as sales agent, in connection with an “at the market offering” under which the Company from time to time may offer and sell shares of its common stock, having an aggregate offering price of up to $12 million (limited to a maximum of 2,790,697 shares). Subject to the terms and conditions of the Sales Agreement, HCW will use its commercially reasonable efforts consistent with its normal trading and sales practices to sell the shares from time to time, based upon the Company's instructions, including any price, time or size limits specified by the Company. The Company has provided HCW with customary indemnification rights, and HCW will be entitled to a commission at a fixed commission rate equal to 3.0% of the gross proceeds per share sold. The Company has no obligation to sell any of the shares and may at any time suspend sales under the Sales Agreement or terminate the Sales Agreement. The Sales Agreement will terminate upon the sale of all of the shares under the Sales Agreement unless terminated earlier by either party as permitted under the Sales Agreement.

In August 2018, the Company entered into an amendment to the Sales Agreement to reflect that the shares will be issued pursuant to a Registration Statement on Form S-3 (Registration No. 333-226319) that was declared effective in August 2018 and that replaced the Company’s previously effective shelf registration statement. In connection with the amendment, the number of shares of common stock that may be sold pursuant to the Sales Agreement was increased from an aggregate offering amount of $12 million to $25 million (limited to a maximum of 4,921,260 shares). All other provisions of the Sales Agreement remained unchanged. During the three months ended March 31, 2019, the Company did not issue shares of common stock under the Sales Agreement. As of March 31, 2019, the Company has issued 149,041 shares of common stock under the Sales Agreement for net proceeds of $1.0 million since inception.

Stock Options and Warrants

The following table summarizes the activity for stock options and warrants for the three months ended March 31, 2019:



	Stock Options							Warrants
	Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value (In Thousands)		Shares	Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value (In Thousands)
Outstanding at December 31, 2018	1,018,530		$	30.50	5.30	$	3.3	30,000	$	5.89	4.19	$	—

Changes during the period:
Granted	199,346		4.90					—	—
Exercised	(240	)	3.50					—	—
Forfeited	—		—					—	—
Expired	(4,002	)	8.30					—	—
Outstanding at March 31, 2019	1,213,634		$	26.40	5.85	$	12.9	30,000	$	5.89	3.95	$	—
Vested at March 31, 2019 or expected to vest in the future	1,185,882		$	26.90	5.76	$	12.9	30,000	$	5.89	3.95	$	—
Vested at March 31, 2019	974,249		$	31.80	4.96	$	12.9	30,000	$	5.89	3.95	$	—

Restricted Stock

During the three months ended March 31, 2019 and 2018, the Company issued restricted stock for services as follows ($ in thousands):



	Three Months Ended March 31,
	2019		2018
Number of restricted stock issued	123,564		127,688
Value of restricted stock issued ($ in thousands)	$	612	$	351

Restricted Stock Units

During the three months ended March 31, 2019 and 2018, the Company issued restricted stock units for services as follows ($ in thousands, except share data):



	Three Months Ended March 31,
	2019		2018
Number of restricted stock units issued	184,454		34,988
Value of restricted stock units issued	$	909	$	133

The weighted average estimated fair value of restricted stock issued for services in the three months ended March 31, 2019 and 2018 was $4.93 and $3.79 per share, respectively. The fair value of the restricted stock units was determined using the Company’s closing stock price on the date of issuance. The vesting terms of restricted stock unit issuances are generally one year, or upon the achievement of performance-based milestones.