– Geographic atrophy (GA) program introduced with complement Factor I (CFI), a key component of the complement cascade, as a payload and utilizing two intravitreal (IVT) capsids, 7m8 and LSV1 – – IVT administration of AAV-CFI using either the 7m8 or LSV1 capsid resulted in high expression levels and was well tolerated in non-human primates (NHPs) – – Presented data on an optogenetics program utilizing an engineered melanopsin mutant that could serve as a therapeutic transgene for optogenetic vision restoration in indications with photoreceptor loss such as advanced GA, among others – – Presented manufacturing strategies for AAV-mediated gene therapies in highly prevalent diseases – REDWOOD CITY, Calif., May 18, 2023 (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 presented new nonclinical data on an IVT gene therapy for the treatment of GA secondary to dry age-related macular degeneration (dry AMD) via expression of CFI at the American Society of Gene & Cell Therapy (ASGCT) 2023 Annual Meeting, in Los Angeles, California. Adverum also presented new research pipeline data supporting the utility of its proprietary adeno-associated virus (AAV) vector platform in ocular gene therapy with presentations on optogenetics and on Chemistry, Manufacturing and Controls (CMC) strategies for AAV-mediated gene therapies in highly prevalent diseases. “The ability to deliver both CFI and an engineered melanopsin leveraging our proprietary capsids via IVT administration demonstrates the strength of our platform at Adverum,” commented Brigit Riley, Ph.D., chief scientific officer of Adverum Biotechnologies. “Similar to wet AMD, patients with GA are forced either to receive frequent, often monthly, injections or to experience faster lesion growth and vision deterioration. We’re in the early stages of development for a GA therapeutic and are excited by the potential for a paradigm shift for dry AMD patients worldwide with a single, in-office, IVT injection creating CFI biofactories in the retina.” Geographic Atrophy Poster Highlights GA is a highly prevalent disease characterized by retinal pigment epithelium (RPE) and photoreceptor death. The inhibition of components of the complement pathway has been shown to meaningfully reduce GA lesion growth. CFI, a rate-limiting enzyme within the complement cascade, naturally blocks the activity of proteins involved in complement overactivation.Continuous expression of CFI in ocular tissue holds the possibility to inhibit complement overactivation, thereby halting GA lesion growth and preserving vision for dry AMD patients. 7m8 and LSV1 capsids packaged with AAV-CFIco, yielded robust intraocular human CFI levels in NHPs. IVT administration of AAV-CFIco via both proprietary capsids was well tolerated, with no anti-inflammatory steroids used at any timepoint in the nonclinical study. Administering an AAV-mediated therapy to express CFI in patients via IVT delivery, a routine in-office procedure, could be an ideal treatment profile for a widely adoptable treatment for GA. Optogenetics Poster Highlights In a poster presentation exploring an optogenetic approach to vision restoration, Adverum presented data on an engineered melanopsin that demonstrated improved kinetics, including speed and light sensitivity, and that may have utility as a therapeutic transgene for optogenetic vision restoration. Melanopsin through its unique ability to regenerate chromophore has the potential to be an effective light sensor candidate by generating pseudo-photoreceptors for optogenetic vision restoration. Chemistry, Manufacturing and Controls (CMC) Poster Highlights In a poster presentation examining CMC strategies for AAV gene therapies, Adverum presented data demonstrating that improved bacmid purity enables lower passage number and higher gene of interest stability, and that manufacturing process changes, such as adding Sf-RVN cells with optimal media (rather than Sf9 cells) or the use of low MOI for rAAV production, can consistently yield higher titer rAAV. The ASGCT poster and oral presentations will be made available on the Publications page of the Adverum website. About Adverum BiotechnologiesAdverum 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 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 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 StatementsStatements 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 nonclinical data on an intravitreal gene therapy for the treatment of geographic atrophy secondary to dry age-related macular degeneration via expression of Complement Factor I, research pipeline data supporting the utility of proprietary adeno-associated virus vector platform in ocular gene therapy in optogenetics and chemistry, manufacturing and controls strategies for AAV-mediated gene therapies in highly prevalent diseases. 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 intravitreal gene therapies. 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 March 31, 2023 filed with the SEC on May 11, 2023. 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 and Media Inquiries Anand ReddiVice President, Head of Corporate Strategy, External Affairs and EngagementAdverum Biotechnologies, Inc.T: 650-649-1358E: areddi@adverum.com