As Filed Pursuant to Rule 424(b)(5)
Registration No. 333-217459
PROSPECTUS
SUPPLEMENT
(To Prospectus Dated May 10, 2017)
$1,031,896
Common Stock
On May 20, 2019, we entered
into an amendment, or the Amendment No. 5, to our Capital on Demand
Sales Agreement, dated as of January 11, 2017 as amended on August 21, 2017, January 25, 2019,
March 11, 2019 and May 9, 2019, or the Original Agreement and, together with the Amendment No. 5, the Sales Agreement, with JonesTrading Institutional Services LLC, or JonesTrading. Under the Amendment No. 5, we increased the
maximum aggregate offering price of the shares of our common stock, $0.001 par value per share, that we may issue and sell from time to time under the Sales Agreement, as amended, from $15,728,009 to $16,759,905. This prospectus supplement only
relates to such additional shares of common stock.
As of May 20, 2019, we have sold an aggregate of $15,568,427 of our common stock under the Sales
Agreement pursuant to our registration statement on Form
S-3
filed with the Securities and Exchange Commission, or the SEC, on April 4, 2014 (File
No. 333-195054)
and our registration statement on Form
S-3
filed with the SEC on May 10, 2017 (File No. 333-217459). As a result of the limitations
discussed below and the current public float of our common stock, and in accordance with the terms of the Sales Agreement, we may offer and sell shares of our common stock having an aggregate offering price of up to $1,031,896 under this prospectus
supplement and accompanying prospectus from time to time through JonesTrading. On May 9, 2019, we filed a prospectus supplement to the prospectus included in our registration statement on Form
S-3
filed
with the SEC on May 10, 2017 (File
No. 333-217459)
offering for sales up to $2,404,594 shares of our common stock under the Sales Agreement, or the Prior Offering. Upon the filing of this prospectus
supplement, we will not make any additional sales of our common stock in connection with the Prior Offering.
We are subject to General Instruction I.B.6
of Form
S-3,
which limits the amounts that we may sell under the registration statement of which this prospectus supplement and the accompanying prospectus forms a part. Pursuant to General Instruction I.B.6
of Form
S-3,
in no event will we sell securities registered on the registration statement of which this prospectus supplement and accompanying prospectus is a part in a public primary offering with a value
exceeding more than
one-third
of our public float in any
12-month
period if our public float, measured in accordance with such instruction, remains below
$75.0 million. As of May 17, 2019, the aggregate market value of our common stock held by
non-affiliates,
or the public float, was $19,550,634, which was calculated based on 1,294,744 shares of our
outstanding common stock held by
non-affiliates
as of the date of May 17, 2019 at a price of $15.10 per share, which was the closing price of our common stock on the NASDAQ Capital Market, or the
Exchange, on May 8, 2019. As of the date hereof, we have sold 530,303 shares of our common stock, adjusted for our stock split on April 3, 2019, for aggregate gross proceeds of approximately $5.5 million, pursuant to General
Instruction I.B.6 of Form
S-3
during the 12 calendar months prior to and including the date of this prospectus supplement.
Our common stock is listed on the Exchange under the symbol ABIO. On May 17, 2019, the last reported sale price of our common stock was $9.41 per
share.
Sales of our common stock, if any, under this prospectus supplement and accompanying prospectus may be made in sales deemed to be at the
market offerings as defined in Rule 415 promulgated under the Securities Act of 1933, as amended, or the Securities Act. JonesTrading is not required to sell any specific number or dollar amount of securities, but will act as a sales agent
using commercially reasonable efforts consistent with its normal trading and sales practices, on mutually agreed terms between JonesTrading and us. There is no arrangement for funds to be received in any escrow, trust or similar arrangement.
The compensation to JonesTrading for sales of common stock sold pursuant to the Sales Agreement will be an amount equal to 3.0% of the gross proceeds of any
shares of common stock sold under the Sales Agreement. In connection with the sale of the common stock on our behalf, JonesTrading will be deemed to be an underwriter within the meaning of the Securities Act and the compensation of
JonesTrading will be deemed to be underwriting commissions or discounts. We have also agreed to provide indemnification and contribution to JonesTrading with respect to certain liabilities, including liabilities under the Securities Act or the
Exchange Act of 1934, as amended, or the Exchange Act.
Investing in our
securities involves a high degree of risk. You should review carefully the risks and uncertainties described under the heading
Risk Factors
on page
S-6
of this
prospectus supplement and under similar headings in the accompanying prospectus and other documents that are incorporated by reference into this prospectus supplement and accompanying prospectus.
NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR DETERMINED IF THIS
PROSPECTUS SUPPLEMENT OR THE ACCOMPANYING PROSPECTUS ARE TRUTHFUL OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.
The date of this prospectus supplement is May 20, 2019.