Adverum Biotechnologies Presents Anatomical Improvements in Intraretinal and Subretinal Fluid After a Single IVT Injection of Ixo-vec (ADVM-022) in the OPTIC Study in Wet AMD

– New data highlight that a single intravitreal injection of Ixo-vec can lead to stable and persistent aflibercept expression through three years resulting in fluid control supporting favorable vision outcomes, as well as decreasing treatment burden by an 81-98% reduction in mean annualized anti-VEGF injections – The 2×10^11 vg/eye (2E11) dose meaningfully reduced fluid volume, including a 93% reduction in intraretinal (IRF) and 55% reduction in subretinal fluid (SRF) from baseline to week 48 – The Phase 2 LUNA trial of Ixo-vec is underway, evaluating the 2E11 and 6×10^10 vg/eye (6E10) dose with enhanced prophylactic steroid regimens for the treatment of wet AMD subjects REDWOOD CITY, Calif., Sept. 30, 2022 (GLOBE NEWSWIRE) — Adverum Biotechnologies, Inc. (Nasdaq: ADVM), a clinical-stage company that aims to establish gene therapy as a new standard of care for highly prevalent ocular diseases, today announced new analyses from the OPTIC study treating wet age-related macular degeneration (wet AMD) during the Late Breaking Developments portion of Retinal Subspecialty Day at the American Academy of Ophthalmology (AAO) 2022 Annual Meeting in Chicago, Illinois. New data presented include the effects of ixoberogene soroparvovec (Ixo-vec, formerly referred to as ADVM-022) on control of IRF and SRF after a single, in-office, intravitreal (IVT) injection in subjects requiring frequent anti-VEGF injections for their wet AMD. “We are pleased to see Ixo-vec’s effects on reducing intraretinal and subretinal fluid in treatment experienced patients in our post-hoc analysis of data generated from the OPTIC trial,” commented Richard Beckman, M.D., chief medical officer of Adverum Biotechnologies. “These data suggest that continuous and consistent expression of aflibercept has a stabilizing effect on the volume of both intraretinal and subretinal fluid, something that bodes well long-term. The connection between fluid fluctuations and long-term visual acuity is the subject of active research and several studies have demonstrated that less fluid fluctuation is associated with better visual outcomes.” Data Highlights Following a single IVT injection of a 2E11 dose of Ixo-vec in OPTIC (n=15), there was a 93% and 55% reduction in mean IRF and SRF volume, respectively, from baseline to Week 48.The percentage of subjects with dry SRF, across both the 6E11 and 2E11 dose groups, increased through Week 48 with a 200% increase in the 2E11 dose group (n=15).Importantly, 60% of OPTIC participants receiving the 2E11 dose had dry IRF at Week 48, representing a 50% increase from baseline. “The meaningful drying of intraretinal fluid and subretinal fluid, as well as reduced exudative volatility observed in OPTIC is highly promising, as we have started to appreciate the relationship between these anatomical outcomes and the potential role on preservation of vision long term in patients with wet AMD,” stated Justis P. Ehlers, M.D., who led the advanced optical coherence tomography analysis. “In addition, the increase in percentage of OPTIC patients achieving complete fluid resolution over time, through Week 48, at the 2E11 dose further reinforces the potential benefits of a single IVT injection of Ixo-vec.” Patient enrollment and dosing are currently underway in LUNA, a double-masked, randomized, Phase 2 trial. Adverum expects to conduct the trial at approximately 40 sites in the U.S. and Europe. LUNA will evaluate Ixo-vec in subjects with wet AMD who are 50 years or older and have demonstrated a response to anti-VEGF treatment. Up to 72 subjects will be randomized equally between the 2E11 dose and new lower 6E10 dose and across four prophylactic steroid regimens. Specific regimens being evaluated include topical difluprednate (Durezol®), IVT dexamethasone (Ozurdex®), or a combination of either topical Durezol® or IVT Ozurdex® with oral prednisone, with the aim of establishing a prophylactic regimen with minimal need for inflammation management post prophylaxis. “The important learnings from the OPTIC trial, such as the association between anatomical improvements and the maintenance of vision and long-term durability, were particularly encouraging, especially as a physician who sees wet AMD patients on a daily basis,” said Dante Pieramici, M.D., partner, California Retinal Consultants, OPTIC investigator, and presenter of the data at AAO. “I am excited to serve as an investigator in Adverum’s LUNA trial, and provide my wet AMD patients with a single, in-office IVT injection that can potentially serve as a functional cure to this debilitating disease.” About Wet Age-Related Macular Degeneration 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 LUNA Trial of Ixo-Vec in Wet AMD Ixoberogene soroparvovec (Ixo-vec) is Adverum’s clinical-stage gene therapy product candidate being developed for the treatment of wet AMD. Ixo-vec utilizes a proprietary vector capsid, AAV.7m8, carrying an aflibercept coding sequence under the control of a proprietary expression cassette. Unlike other ophthalmic gene therapies that require surgery to administer the gene therapy under the retina (sub-retinal approach), Ixo-vec is designed to be administered as a one-time IVT injection in the office, deliver long-term efficacy, reduce the burden of frequent anti-vascular endothelial growth factor (VEGF) injections, optimize patient compliance, and improve vision outcomes for patients with wet AMD. Ixo-vec received PRIME designation from the European Medicines Agency in June 2022. The LUNA trial is a multicenter, double-masked, randomized, parallel-group Phase 2 study evaluating two doses of Ixo-vec, the 2×10^11 vg/eye dose and a new, lower 6×10^10 vg/eye dose, in wet AMD. The trial is designed to randomize up to 72 participants equally across two doses and four prophylactic steroid regimens in approximately 40 sites in the U.S. and Europe. About Adverum Biotechnologies Adverum Biotechnologies (NASDAQ: ADVM) is a clinical-stage company that aims to establish gene therapy as a new standard of care for highly prevalent ocular diseases with the aspiration of developing functional cures to restore vision and prevent blindness. Leveraging the research capabilities of its proprietary, intravitreal (IVT) platform, Adverum is developing durable, single-administration therapies, designed to be delivered in physicians’ offices, to eliminate the need for frequent ocular injections to treat these diseases. Adverum is evaluating its novel gene therapy candidate, ixoberogene soroparvovec (Ixo-vec, formerly referred to as ADVM-022), as a one-time, IVT injection for patients with neovascular or wet age-related macular degeneration. By overcoming the challenges associated with current treatment paradigms for these debilitating ocular diseases, Adverum aspires to transform the standard of care, preserve vision, and create a profound societal impact around the globe. 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 the potential benefits of Ixo-vec and the timing of preliminary data from the LUNA trial evaluating the same. 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 timing of commencement and completion of clinical trials; regulatory uncertainties; enrollment uncertainties; the results of early clinical trials not always being predictive of future clinical trials and results; and the potential for future complications or side effects in connection with use of Ixo-vec. 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 Quarterly Report on Form 10-Q for the quarter ended June 30, 2022 filed with the SEC on August 11, 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. Corporate & Investor Inquiries Anand ReddiVice President, Head of Corporate Strategy, External Affairs and EngagementAdverum Biotechnologies, Inc.T: 650-649-1358E: [email protected] Media Megan TalonAssociate Director, Corporate CommunicationsAdverum Biotechnologies, Inc.T: 650-649-1006E: [email protected]