On October 16, 2023, Aldeyra Therapeutics, Inc. announced that it received minutes from a late-cycle review meeting (the " Minutes") with the U.S. Food and Drug Administration (the "FDA") relating to the new drug application ("NDA") for reproxalap for the treatment of the signs and symptoms of dry eye disease. The Minutes identified substantive review issues in connection with the NDA for reproxalap. The FDA stated that [i]t does not appear that have data to support the clinical relevance of the ocular signs to support dry eye indication." In subsequent communications between Aldeyra and the FDA, Aldeyra has submitted responses to the FDA that Aldeyra believes to be sufficient to mitigate the identified issues, but the FDA has not directly opined on the sufficiency of the information submitted, has no legal obligation to review the information submitted by Aldeyra, and has indicated that Aldeyra needs to conduct an additional clinical trial to satisfy efficacy requirements.

As such, based on the time remaining in the NDA review cycle, the FDA may not be in the position to approve the NDA for reproxelap on or about the Prescription Drug User Fee Act ("PDUFA") target action date of November 23, 2023 or afterwards, and it may issue a Complete Response Letter and require that Aldeyra conduct additional clinical trials and submit the results of those clinical trials before the application will be considered. The following risk factor is provided to supplement Aldeyra's risk factors previously disclosed under the heading Risk Factors" in Aldeyra's Annual Report on Form 10-K for the year ended December 31, 2022 and Aldeyra's Quarterly Reports on Form 10-Q for the quarters ended March 31, 2023 and June 30, 2023. The FDA has substantial discretion in the approval process and may differ with Aldeyra's interpretation of or the sufficiency of the data from Aldeyra's clinical trials.

Clinical trial results frequently are susceptible to varying interpretations and regulatory authorities may differ on what are appropriate methods for analyzing data, which may delay, limit or prevent regulatory approvals. For example, Aldeyra has received Minutes from a late-cycle review Meeting with the FDA, which noted substantive review issues in connection with The NDA for reproxalAP for the treatment of the signsand symptoms of dry eye disease. of the reproxalap NDA, the FDA has requested certain chemistry, manufacturing, and controls ("CMC") details.

In subsequent communications between AldeyRA and the FDA, AldeyRA has submitted responses to the FDA That Aldeyra has submitted responses To the FDA that Aldeyra has submitted responses of the information submitted, but the FDA has not direct opined on the su efficiency of the information submitted, has not directly opined on The sufficiency of the information submit, has no legal obligation to reviewed the information submitted by AldeyRA, and has indicated that Aldayra needs to conduct an additionalclinical trial to satisfy efficacy requirements.