AlloVir Inc. announced the company's 2023 priorities and anticipated future milestones across its pipeline of virus-specific T cell therapies, including its lead investigational therapy posoleucel. Viral infections are a leading cause of non-relapse mortality, generate substantial healthcare expenditures, exact a significant emotional burden on patients and their caregivers, and unfortunately most viruses targeted by posoleucel currently have no preventive therapies." Posoleucel is an investigational T cell therapy that targets multiple viruses that commonly reactivate in patients who have received allogeneic hematopoietic cell transplants (allo-HCTs) or solid organ transplants. The therapy is being evaluated in three Phase 3 registrational studies for three distinct indications -- the prevention of clinically significant infections or disease from adenovirus (AdV), BK virus (BKV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesvirus-6 (HHV-6) and JC virus (JCV), the treatment of virus-associated hemorrhagic cystitis (vHC), and the treatment of AdV infection, all in allo-HCT patients.

These viral infections have limited to no approved preventive therapies and treatment options, threatening patient survival. Posoleucel Multi-Virus Prevention in Allo-HCT Patients Multi-virus prevention represents the most transformational potential use of posoleucel, moving upstream to prevent the progression of viral reactivations to clinically significant infections and avoid the deleterious downstream effects of these infections. Final data from the open-label, Phase 2 multi-virus prevention study of posoleucel were recently presented at the 64(th) ASH Annual Meeting and Exposition.

Results showed that high-risk allo-HCT patients who received posoleucel had substantially lower than expected rates of clinically significant viral infections from posoleucel's six target viruses, and that repeat dosing was generally safe and well tolerated. The posoleucel Phase 3 multi-virus prevention trial (NCT05305040) is enrolling adult and pediatric patients in the U.S., Europe, Asia, Australia and Canada. Enrollment is expected to complete by year-end 2023, enabling topline data in mid-2024.

vHC and AdV Treatment in Allo-HCT Patients Global enrollment is ongoing in Phase 3 registrational studies of posoleucel for the treatment of vHC (NCT04390113) and AdV infection (NCT05179057), both in adult and pediatric allo-HCT patients. Given the high proportion of sites participating in multiple posoleucel Phase 3 studies and the intentional prioritization of the multi-virus prevention trial, both the vHC and AdV studies are expected to complete enrollment by year-end 2023, with topline data anticipated in 2024. BKV Treatment in Kidney Transplant Patients Topline final data from the Phase 2 study (NCT04605484) of posoleucel for the treatment of BK viremia in kidney transplant patients are expected in the first quarter of 2023.

These data will inform next steps for this potential indication as well as broader strategy in solid organ transplant patients. Earlier Stage PipelineAlloVir's early clinical and preclinical VST therapy candidates provide portfolio expansion opportunities, with pipeline advancement led by AlloVir or a potential partner. ALVR106 A Phase 1b/2 proof-of-concept clinical study (NCT04933968) of ALVR106 for the treatment of respiratory syncytial virus (RSV), human metapneumovirus, parainfluenza, and influenza, is enrolling auto- and allo-HCT patients in the U.S. into the dose escalation part of this two-part study.

ALVR107 Preclinical and IND-enabling studies of ALVR107 for chronic HBV have been completed and continue to support the potential for ALVR107 to achieve functional HBV cure. The company expects to initiate clinical development of ALVR107 upon completion of the posoleucel Phase 3 registrational studies. ALVR109 The company continues to make ALVR109 available to physicians in response to appropriate compassionate use requests.

Positive reports of ALVR109 compassionate use in immune-compromised patients have been published and presented at the 2022 American Transplant Congress, providing important insight into the potential utility of a virus-specific T cell approach to treating respiratory viruses in immunocompromised patients.