On January 11, 2017, the Company entered into a Capital on Demand^TM Sales Agreement (the Sales Agreement) with JonesTrading Institutional Services LLC, as agent (JonesTrading), pursuant to which the Company may offer and sell, from time to time through JonesTrading, shares of the Company’s common stock, par value $0.001 per share (the Common Stock), having an aggregate offering price of up to $7.3 million. On August 21, 2017, January 25, 2019 and March 11, 2019, the Company amended its Capital on Demand Sales Agreement. The amendments, among other things, increased the maximum aggregate offering value of shares of the Company’s common stock which the Company may issue and sell from time to time under the Sales Agreement from $7.3 million to $13.3 million (the Shares).

Under the amended Sales Agreement, JonesTrading may sell the Shares by any method permitted by law and deemed to be an “at the market offering” as defined in Rule 415 promulgated under the Securities Act of 1933, as amended, including sales made directly on or through the Nasdaq Capital Market, on any other existing trading market for the Common Stock or to or through a market maker. In addition, under the amended Sales Agreement, JonesTrading may sell the Shares by any other method permitted by law, including in negotiated transactions. The Company may instruct JonesTrading not to sell Shares if the sales cannot be effected at or above the price designated by the Company from time to time.

The Company is not obligated to make any sales of the Shares under the amended Sales Agreement. The offering of Shares pursuant to the amended Sales Agreement will terminate upon the earlier of (a) the sale of all of the Shares subject to the amended Sales Agreement or (b) the termination of the amended Sales Agreement by JonesTrading or the Company, as permitted therein.

The Company paid JonesTrading a commission rate equal to 3.0% of the aggregate gross proceeds from each sale of Shares and agreed to provide JonesTrading with customary indemnification and contribution rights. The Company will also reimburse JonesTrading for certain specified expenses in connection with entering into and amending the Sales Agreement.

Under the amended Sales Agreement, the Company sold an aggregate of 325,304, 118,546 and 148,751 shares of Common Stock, for net proceeds of approximately $2.9 million, $3.4 million and $6.1 million during the three months ended March 31, 2019 and the years ended December 31, 2018 and 2017, respectively, including initial expenses for executing the “at the market offering” and commissions to the placement agent.

Warrants to purchase shares of common stock were previously granted as part of various financing and business agreements. All outstanding warrants were recorded in additional paid-in capital at their estimated fair market value at the date of grant using a Black-Scholes option-pricing model.

As of March 31, 2019, these warrants, by year of expiration, are summarized below:

Year of Expiration	Number of Warrants		Weighted Average Exercise Price
2020		2,461	$	287.28
2022		133,401		109.80
		135,862	$	113.04