Aldeyra Therapeutics, Inc. Prices Public Offering

LEXINGTON, MA--(Marketwired - Feb 14, 2017) - Aldeyra Therapeutics, Inc. ( NASDAQ : ALDX ) (Aldeyra), a biotechnology company focused on the development of products to treat diseases related to aldehydes, today announced the pricing of an underwritten public offering of 2,222,222 shares of its common stock at a price to the public of $4.50 per share. In connection with the offering, Aldeyra granted the underwriters a 30-day option to purchase 333,333 additional shares of common stock. All of the shares in the offering are being sold by Aldeyra. This offering is expected to close on or about February 17, 2017 subject to customary closing conditions.

Stifel and Canaccord Genuity are acting as joint book-running managers and Laidlaw & Company (UK) Ltd. is acting as the lead manager for the offering.

A shelf registration statement on Form S-3 relating to the public offering of the shares of common stock described above was filed with the Securities and Exchange Commission (SEC) and declared effective by the SEC on September 1, 2015. A preliminary prospectus supplement and accompanying prospectus relating to and describing the terms of the offering has been filed with the SEC and is available on the SEC's web site at www.sec.gov . Copies of the final prospectus supplement and accompanying prospectus relating to these securities may also be obtained by sending a request to: Stifel, Nicolaus & Company, Incorporated, Attention: Syndicate, One Montgomery Street, Suite 3700, San Francisco, California 94104, by calling (415) 364-2500, or by email at syndprospectus@stifel.com ; or by contacting Canaccord Genuity Inc., Attention: Syndicate Department, 99 High Street, 12th Floor, Boston, Massachusetts 02110, by telephone at (617) 371-3900, or by email at prospectus@canaccordgenuity.com .

This press release does not constitute an offer to sell or the solicitation of an offer to buy any of these securities, nor will there be any sale of these securities in any state or other jurisdiction in which such offer, solicitation or sale is not permitted.

About Aldeyra Therapeutics, Inc.

Aldeyra Therapeutics, Inc. is a biotechnology company devoted to improving lives by inventing, developing and commercializing products that treat diseases thought to be related to endogenous aldehydes, a naturally occurring class of pro-inflammatory and toxic molecules. Aldeyra's lead product candidate, ADX-102, is an aldehyde trap in development for ocular inflammation, as well as for Sjögren-Larsson Syndrome and Succinic Semi-Aldehyde Dehydrogenase Deficiency, two inborn errors of aldehyde metabolism. Aldeyra's product candidates have not been approved for sale in the U.S. or elsewhere.

Safe Harbor Statement This release contains forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended, including but not limited to statements regarding the closing of the public offering. These forward-looking statements are subject to a number of risks, including the satisfaction of customary closing conditions related to the proposed public offering and the risk factors set forth from time to time in Aldeyra's SEC filings, including but not limited to the risks that are described in the "Risk Factors" and "Management's Discussion and Analysis of Financial Condition and Results of Operations" sections of Aldeyra's Annual Report on Form 10-K for the year ended December 31, 2015, and Aldeyra's Quarterly Report on Form 10-Q for the quarter ended September 30, 2016, which are on file with the SEC and available on the SEC's website at www.sec.gov . Additional factors may be set forth in Aldeyra's Annual Report on Form 10-K for the year ended December 31, 2016, to be filed with the SEC in the first quarter of 2017. In addition to the risks described above and in Aldeyra's other filings with the SEC, other unknown or unpredictable factors also could affect Aldeyra's results. No forward-looking statements can be guaranteed and actual results may differ materially from such statements. The information in this release is provided only as of the date of this release, and Aldeyra undertakes no obligation to update any forward-looking statements contained in this release on account of new information, future events, or otherwise, except as required by law.