Adverum Biotechnologies Presents Additional Efficacy and Safety Data from the OPTIC Trial of ADVM-022 in Wet AMD at the ARVO 2022 Annual Meeting

– Poster highlights analysis of baseline neutralizing antibodies to AAV.7m8 and impact on ADVM-022 efficacy and safety in OPTIC – – Reductions in mean annualized anti-VEGF injections ranged from 81% in all patients to 94% in those with NAbs <1:125 at 2 X 10^11 vg/eye – REDWOOD CITY, Calif., May 01, 2022 (GLOBE NEWSWIRE) — Adverum Biotechnologies, Inc. (Nasdaq: ADVM), a clinical-stage gene therapy company targeting unmet medical needs in ocular and rare diseases, today announced the presentation of new post-hoc analysis from the OPTIC study of ADVM-022 in wet age-related macular degeneration (wet AMD) during The Association for Research in Vision and Ophthalmology (ARVO) 2022 Annual Meeting in Denver, Colorado and virtually. The new data from OPTIC assessed the potential impact of baseline levels of neutralizing antibodies (NAbs) on efficacy and safety outcomes with ADVM-022 (AAV.7m8-aflibercept). It is a common practice for companies developing adeno-associated viruses (AAV) vector therapies to consider how the presence of pre-existing NAbs might influence treatment efficacy or safety parameters. In all subjects, a single intravitreal (IVT) injection gene therapy at the 2 X 10^11 vg/eye (2E11) dose demonstrated a greater than 80% reduction in annualized anti-vascular endothelial growth factor (VEGF) injections, as previously reported.   In subjects with baseline NAbs <1:125, the reductions in mean annualized injection frequency increased to 94%. There was no correlation between baseline NAbs and safety events. “The data shows great promise of ADVM-022 for wet AMD patients regardless of baseline levels of neutralizing antibodies to AAV.7m8, and the potential to achieve even higher efficacy in those whose NAbs titers are below 1:125,” said Laurent Fischer, M.D., president and chief executive officer at Adverum Biotechnologies. “We are excited to share these results with the ophthalmology community at ARVO. We continue to plan for the initiation of a Phase 2 wet AMD clinical trial evaluating ADVM-022 at the 2E11 vg/eye dose and a lower 6×10^10 vg/eye dose with new enhanced prophylactic steroid regimens, which are expected to include local steroids and a combination of local and systemic steroids. The first patient dosed for the Phase 2 study is expected in the third quarter of 2022.” Data Highlights The mean annualized anti-VEGF injection rate was reduced by 81% in all participants receiving 2E11 vg/eye and 94% in participants with NAbs titers <1:125, suggesting that those with baseline NAbs to AAV2.7m8 <1:125 were likely to demonstrate more robust aflibercept protein expression and require even fewer supplemental anti-VEGF injections.67% (10/15) of 2E11 vg/eye subjects had baseline NAbs titers of <1:125.Both doses of ADVM-022 were well tolerated with the 2×10^11 vg/eye dose requiring less topical corticosteroid therapy to alleviate inflammation. At most recent follow-up, no participants in the 2E11 vg/eye required any topical corticosteroids to treat inflammation.No correlation between baseline NAbs and safety events was observed. Additionally, baseline NAbs were not associated with occurrence or duration of inflammation. “These new data give us important insight into the high levels of efficacy that wet AMD patients experience following treatment with ADVM-022, particularly among those whose baseline levels of NAbs are below 1:125,” said Szilárd Kiss, M.D., Bob and Dolores Hope – Robert M. Ellsworth, M.D. Distinguished Associate Professor in Ophthalmology, member of Adverum’s Scientific Advisory Board. “We continue to seek ways to address critical areas of unmet needs in wet AMD patients and caregivers by decreasing the treatment burden from frequent anti-VEGF injections, which are the current standard of care. We look forward to providing additional data on ADVM-022 and the impact of neutralizing antibodies at upcoming medical meetings.” ARVO 2022 Presentation Presentation Title: Phase 1 Study of Intravitreal (IVT) Gene Therapy with ADVM-022 for Neovascular AMD (OPTIC Trial): The Role of Neutralizing Antibodies (NAbs)Presentation: 306 – F0109 (Poster Session)Session Title: AMD and Diabetic RetinopathyDate: May 1, 2022Time: 12:15 PM to 2:15 PM MDTPresenter: Szilárd Kiss, M.D., Bob and Dolores Hope – Robert M. Ellsworth, M.D. Distinguished Associate Professor in Ophthalmology, Weill Cornell Medical College; Associate Dean, Clinical Compliance, Vice-Chair, Research and Compliance, Weill Cornell Medicine Ophthalmology About Wet Age-Related Macular Degeneration (Wet AMD) Wet AMD, also known as neovascular AMD or nAMD, is an advanced form of AMD, affecting approximately 10% of patients living with AMD. Wet AMD is a leading cause of blindness in patients over 65 years of age, with a prevalence of approximately 20 million individuals worldwide living with this condition. The incidence of new cases of wet AMD is expected to grow significantly worldwide as populations age. AMD is expected to impact 288 million people worldwide by 2040, with wet AMD accounting for approximately 10% of those cases. About OPTIC Trial of ADVM-022 in Wet AMD ADVM‑022 is Adverum’s clinical-stage gene therapy product candidate being developed for the treatment of wet AMD. ADVM-022 utilizes a propriety vector capsid, AAV.7m8, carrying an aflibercept coding sequence under the control of a proprietary expression cassette. Unlike other ophthalmic gene therapies that require a surgery to administer the gene therapy under the retina (sub-retinal approach) ADVM-022 has the advantage of being administered as a one-time IVT injection in the office and is designed to deliver long-term efficacy and reduce the burden of frequent anti-VEGF injections, optimize patient compliance, and improve vision outcomes for patients with wet AMD. The OPTIC trial is designed as a multi-center, open-label, dose-ranging, safety and efficacy trial of ADVM-022 in patients with wet AMD who have demonstrated responsiveness to anti-VEGF treatment. Patients in OPTIC are treatment experienced, and previously required frequent anti-VEGF injections to manage their wet AMD and to maintain functional vision. About Adverum Biotechnologies Adverum Biotechnologies (Nasdaq: ADVM) is a clinical-stage gene therapy company targeting unmet medical needs in serious ocular and rare diseases. Adverum is evaluating its novel gene therapy candidate, ADVM-022, as a one-time, intravitreal injection for the treatment of patients with neovascular or wet age-related macular degeneration. For more information, please visit www.adverum.com. Forward-looking Statements Statements contained in this press release regarding events or results that may occur in the future are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements include but are not limited to: statements regarding Adverum’s plans to initiate a Phase 2 trial of ADVM-022 in wet AMD at the 2 X 10^11 vg/eye dose and a new, lower 6 X 10^10 vg/eye dose; and Adverum’s expectation that the first patient in the Phase 2 study will be dosed in the third quarter of 2022. Actual results could differ materially from those anticipated in such forward-looking statements as a result of various risks and uncertainties, including risks inherent to, without limitation: Adverum’s novel technology, which makes it difficult to predict the time and cost of product candidate development and regulatory uncertainties; the results of early clinical trials not always being predictive of future results; and the potential for future complications or side effects in connection with use of ADVM-022. Additional risks and uncertainties facing Adverum are set forth under the caption “Risk Factors” and elsewhere in Adverum’s Securities and Exchange Commission (SEC) filings and reports, including Adverum’s Annual Report on Form 10-K for the year ended December 31, 2021 filed with the SEC on March 29, 2022. All forward-looking statements contained in this press release speak only as of the date on which they were made. Adverum undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made. Inquiries Anand Reddi Vice President, Head of Corporate Strategy and External Affairs & Engagement Adverum Biotechnologies, Inc. T: 650-649-1358 Investor Laurence WattsGilmartin GroupT: 619-916-7620E: [email protected] Media Megan TalonAssociate Director, Corporate CommunicationsAdverum Biotechnologies, Inc.T: 650-649-1006E: [email protected]