Outlook Therapeutics, Inc.

The following risk factors supplement and, to the extent inconsistent therewith, supersede the risk factors previously disclosed in Exhibit 99.1 to the Company’s Current Report on Form 8-K filed with the SEC on August 12, 2026. You should carefully consider these risk factors together with all other information contained in this Quarterly Report on Form 10-Q and in our Annual Report on Form 10-K for the year ended September 30, 2025, filed with the SEC on December 19, 2025, before making any investment decision. If any of these risks occurs, our business, financial condition, results of operations and prospects could be materially adversely affected.

There is substantial doubt about our ability to continue as a going concern. We will need to raise substantial additional capital to fund the commercialization of LYTENAVA and support our operations until we are able to generate sufficient revenue from the sales of LYTENAVA. This additional funding may not be available on acceptable terms or at all. Failure to obtain this necessary capital when needed may force us to delay, limit or terminate our commercialization and product development efforts or other operations.

Developing and commercializing pharmaceutical products are expensive, risky and lengthy processes. LYTENAVA has been approved for marketing for the treatment of wet AMD in adults in the US, EU and UK, however we have not generated material revenue from sales of LYTENAVA. We expect to incur increased expenses in connection with our ongoing activities, particularly as described in the risk factor entitled “We have incurred significant losses and negative cash flows from operations since our inception and expect to continue to incur significant losses and negative cash flows from operations for the foreseeable future and may not achieve consistent future profitability for some time, if ever.”

As of June 30, 2026, our cash and cash equivalents balance was $11.2 million. We estimate that our cash and cash equivalents as of June 30, 2026, together with $51.1 million in net proceeds from our August 2026 Offering, will only be sufficient to fund our operations into the second quarter of calendar year 2027. Additionally, as of June 30, 2026, we had $20.3 million of principal, accrued interest and exit fees outstanding under the March 2026 Note. The March 2026 Note bears interest at the prime rate, as published in The Wall Street Journal, plus 3%, subject to a minimum rate of 9.5%, and matures on June 16, 2027. Beginning on September 16, 2026, Atlas has the right to redeem up to $3.0 million of the outstanding balance under the March 2026 Note per calendar quarter. All cash payments made by us under the March 2026 Note, including prepayments, redemptions, or repayment at maturity, are subject to a 7.5% exit fee.

Because our cash and cash equivalents, together with $51.1 million of net proceeds from our August 2026 Offering, will not be adequate to fund our currently planned operations through at least the 12 months from the date of this Quarterly Report, there is substantial doubt about our ability to continue as a going concern. We will require substantial additional capital to continue to operate as a going concern. Although we continue to pursue discussions with additional potential strategic partners for LYTENAVA outside of the US, there is no guarantee that we will be successful in reaching any such agreement, nor that such agreement, if successful, will cover the anticipated commercialization costs for LYTENAVA. Our operating plan may also change as a result of many factors currently unknown to us, and we may need to seek additional funds sooner than planned, through public or private equity or debt financings, third-party funding, marketing and distribution arrangements, as well as through other collaborations, strategic alliances and licensing arrangements, or a combination of these approaches. Even if we believe we have sufficient funds for our current or future operating plans, we may seek additional capital if market conditions are favorable or if we have specific strategic considerations.

Any additional fundraising efforts may divert our management from their day-to-day activities, which may adversely affect our ability to develop and commercialize our product candidates. In addition, we cannot guarantee that future financing will be available in sufficient amounts or on terms acceptable to us, if at all. We may experience difficulties in accessing the capital markets due to external factors beyond our control, such as volatility in the equity markets for emerging biotechnology companies and general economic and market conditions both in the US and abroad. For example, our ability to raise additional capital may be adversely impacted by global economic conditions and disruptions to and volatility in the credit and financial markets in the US and worldwide, such as has been experienced recently due in part to, among other things, the impacts of inflation, ongoing overseas conflict, and disruptions in access to bank deposits and lending commitments due to bank failure. We cannot be certain that we will be able to obtain financing on terms acceptable to us, or at all. Our failure to obtain adequate and timely funding will adversely affect our business and

our ability to launch and commercialize LYTENAVA and develop our technology and product candidates. Moreover, the terms of any financing may negatively impact the holdings or the rights of our stockholders, and the issuance of additional securities, whether equity or debt, by us or the possibility of such issuance may cause the market price of our securities to decline. The incurrence of indebtedness could result in increased fixed payment obligations, and we may be required to agree to certain restrictive covenants, such as limitations on our ability to incur additional debt, limitations on our ability to acquire, sell or license intellectual property rights and other operating restrictions that could adversely impact our ability to conduct our business. We may be required to relinquish rights to some of our technologies or product candidates or otherwise agree to terms unfavorable to us, in order to obtain necessary funding, any of which may harm our business, operating results and prospects. If we are unable to obtain funding on a timely basis, we may be required to significantly curtail, delay or discontinue the commercialization of LYTENAVA. We may also be unable to expand our operations or otherwise capitalize on our business opportunities, as desired, which could harm our business, financial condition and results of operations. Additionally, if we are unable to obtain the substantial additional funding needed to operate our business, our business and prospects would be materially and adversely affected, and we may be required to cease operations entirely, liquidate all or a portion of our assets, and/or seek protection under the US Bankruptcy Code, and our stockholders may lose all or part of their investment.