AlloVir Reports Second Quarter 2023 Financial Results Company s three Phase 3 global registrational trials for its allogeneic, off-the-shelf, virus-specific T cell therapy, posoleucel, in three distinct, first-to-market

AlloVir Reports Second Quarter 2023 Financial Results

Company s three Phase 3 global registrational trials for its allogeneic, off-the-shelf, virus-specific T cell therapy, posoleucel, in three distinct, first-to-market indications in allo-HCT patients

continue to enroll, with data anticipated in second half of 2024

Positive data from the Phase 2 trial of posoleucel for treatment of

BK viremia in kidney transplant recipients presented orally at late-breaking session at the American Transplant Congress (ATC 2023)

ALVR106, a multi-respiratory virus-specific T cell therapy targeting human metapneumovirus, influenza, parainfluenza, and respiratory

syncytial virus, completed enrollment in the dose-escalation (Part A) portion of the Phase 1b/2a clinical trial in HCT and solid organ transplant patients

Recent stock offering extends cash runway through Phase 3 data readouts and into 2025

Waltham, Mass August 3, 2023 AlloVir, Inc. (Nasdaq: ALVR), a late-clinical stage allogeneic T cell immunotherapy

company, today reported financial results from the second quarter ended June 30, 2023. The company shared progress across its allogeneic, off-the-shelf

virus-specific T cell (VST) programs, including its lead investigational therapy, posoleucel, for prevention and treatment of life-threatening infections and diseases from up to six viruses that commonly impact patients following allogeneic

hematopoietic cell transplant (allo-HCT), and for the treatment of BK viremia (BKV) in adult kidney transplant recipients.

We are excited to be

advancing our company s three Phase 3 global registrational trials of posoleucel for three indications that threaten allo-HCT recipients. Treating and preventing life-threatening viral infections using T cells that focus on restoring natural

immunity addresses a significant unmet need for allo-HCT patients, which could have a significant impact on patient outcomes, morbidity, and survival, said Diana Brainard, M.D., Chief Executive Officer, AlloVir. We are very pleased with

our progress to date and are on track to report data from all three studies in the second half of 2024.

Upcoming Highlights/Activities

Second Quarter Financial Results

2023 Financial Guidance

AlloVir s lead product, posoleucel, is in late-stage clinical development as an allogeneic, off-the-shelf, multi-virus-specific T cell therapy targeting six viral pathogens in immunocompromised individuals: adenovirus (AdV), BK viremia (BKV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesvirus-6 (HHV-6) and JC virus (JCV). In a Phase 2 open-label study of posoleucel for the prevention of clinically significant infections due to the six viruses

posoleucel targets, 88% of allo-HCT patients who received posoleucel remained free of clinically significant infections through week 14, the primary endpoint. Moreover, the non-relapse mortality rate in

patients who received posoleucel was 0% through the 52-week follow-up visit. Additionally, in the positive Phase 2 proof-of-concept CHARMS treatment study, which enrolled allo-HCT recipients infected by one or more of the six viruses posoleucel targets, more than 90% of patients who failed conventional treatment

and received posoleucel demonstrated a complete or partial clinical response based on predefined criteria.

AlloVir is a leading late-clinical stage cell therapy company focused on restoring natural immunity against life-threatening viral diseases in pediatric

and adult patients with weakened immune systems. The company s innovative and proprietary technology platform leverages off-the-shelf, allogeneic, single-and

multi-virus-specific T cells for patients with T cell deficiencies who are at risk from the life-threatening consequences of viral diseases. AlloVir s technology and manufacturing process enable the potential for the treatment and prevention of

a spectrum of devastating viruses with each single allogeneic cell therapy. The company is advancing multiple mid- and late-stage clinical trials across its product portfolio. For more information,

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including,

without limitation, statements regarding the potential of posoleucel as a treatment for three distinct indications, the potential of posoleucel to prevent infection or disease, the potential of posoleucel to treat vHC or AdV, the timing of data

readouts for our three Phase 3 studies, the projection that our cash will fund operations through data readouts for our three Phase 3 trials and into 2025, that preventing viral infections in allo-HCT patients could be transformational, our

anticipated commercial launch in 2025, AlloVir s development and regulatory status of its product candidates, the planned conduct of its preclinical studies, and clinical trials and its prospects for success in those studies and trials, and its

strategy, business plans and focus. The words may, will, could, would, should,

expect, plan, anticipate, intend, believe, estimate, predict, project, potential,

continue, target and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Any forward-looking statements in this press release

are based on management s current expectations and beliefs and are subject to a number of risks, uncertainties, and important factors that may cause actual events or results to differ materially from those expressed or implied by any

forward-looking statements contained in this press release, including, without limitation, those related to the safety and efficacy of posoleucel, AlloVir s financial results, the timing for the initiation and successful completion of

AlloVir s clinical trials of its product candidates, whether and when, if at all, AlloVir s product candidates will receive approval from the U.S. Food and Drug Administration (FDA), or other foreign regulatory authorities,

competition from other biopharmaceutical companies, supply chain, and business operations and other risks identified in AlloVir s SEC filings, including AlloVir s form 10-Q for the period

ended March 31, 2023. AlloVir cautions you not to place undue reliance on any forward-looking statements, which speak only as of the date they are made. AlloVir disclaims any obligation to publicly update or revise any such

statements to reflect any change in expectations or in events, conditions, or circumstances on which any such statements may be based, or that may affect the likelihood that actual results will differ from those set forth in the forward-looking

statements. Any forward-looking statements contained in this press release represent AlloVir s views only as of the date hereof and should not be relied upon as representing its views as of any subsequent date.

CONSOLIDATED BALANCE SHEETS

(unaudited, in thousands)

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

(unaudited, in thousands, except share and per share data)