XML 24 R13.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Equity Financings and Warrants | 12 Months Ended
--- | ---
Dec. 31, 2015
Equity [Abstract] |
Equity Financings and Warrants | (7) Equity Financings and Warrants 2015 Equity Financing Private Investment in Public Entity (PIPE) Transaction On June 16, 2015, the Company sold an aggregate of 6,003,082 security units, made up of an aggregate 6,003,082 shares of the Company’s common stock and warrants to purchase an aggregate of 2,401,233 shares of the Company’s common stock, at a purchase price of $6.1635 per unit, for aggregate net proceeds of approximately $34.2 million. The warrants became exercisable on December 13, 2015, expire on June 16, 2022, and have an exercise price of $6.1012 per share. The warrants provide for cashless exercise and settlement in unregistered shares if there is no effective registration statement registering, or the prospectus contained therein is not available for the issuance of the shares of common stock underlying the warrants at the time of exercise. The Company’s Registration Statement on Form S-3 registering these shares of common stock, including the shares of common stock underlying the warrants, issued in the transaction for public resale was declared effective by the Securities and Exchange Commission on July 20, 2015. 2014 Equity Financing Registered Direct Offering On February 7, 2014, the Company sold an aggregate of 730,890 shares of the Company’s common stock and warrants to purchase an aggregate of 182,722 shares of the Company’s common stock at a purchase price of $11.90 per share of Common Stock, for aggregate net proceeds of approximately $7.9 million. The warrants were exercisable upon issuance, expire on February 7, 2019, and have an exercise price of $14.875 per share. The offering was effected as a takedown off the Company’s Registration Statement on Form S-3, as amended, which became effective on April 4, 2011, pursuant to a prospectus supplement filed with the Securities and Exchange Commission on February 4, 2014. The warrants provide for cashless exercise and settlement in unregistered shares if there is no effective registration statement registering, or the prospectus contained therein is not available for the issuance of the shares of common stock underlying the warrants at the time of exercise. Warrants Warrants to purchase shares of common stock were 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 December 31, 2015, these warrants, by year of expiration, are summarized below:
Year of Expiration |  | Number of Warrants |  |  | Weighted Average Exercise Price |
2016 |  |  | 82,816 |  |  | $ | 68.19 |
2017 |  |  | 24,124 |  |  |  | 17.89 |
2018 |  |  | 963,153 |  |  |  | 11.77 |
2019 |  |  | 224,323 |  |  |  | 15.73 |
2020 |  |  | 44,299 |  |  |  | 15.96 |
2022 |  |  | 2,401,233 |  |  |  | 6.10 |
|  |  | 3,739,948 |  |  | $ | 9.70 |

X
- Definition Description of equity financings during the periods presented and information related to outstanding warrants of company stock. + References No definition available. + Details
Name: | abio_EquityFinancingsAndWarrantsDisclosureTextBlock
Namespace Prefix: | abio_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_EquityAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration