AlloVir provides updates on phase III clinical development program for posoleucel, an allogeneic virus-specific T cell therapy.

The company will discontinue its three global Phase III posoleucel studies – for prevention of clinically significant infections or diseases by multiple viruses, treatment of virus-associated hemorrhagic cystitis (vHC), and treatment of adenovirus (AdV) – following allogeneic hematopoietic cell transplant (allo-HCT).

The company made the determination following three pre-planned analyses by three independent Data Safety Monitoring Boards (DSMBs) each of which recommended stopping its respective trial for futility after a review of the data suggested that each study was unlikely to meet its primary endpoint. There were no observed safety concerns raised by any of the DSMBs.

AlloVir is in the process of notifying regulatory agencies and clinical trial investigators involved in these trials of the findings.

"While we are disappointed by the unexpected outcome of these trials, we are encouraged by the apparent safety profile of posoleucel,” said Diana Brainard, MD, Chief Executive Officer of AlloVir. “In light of the DSMB recommendations, we will discontinue the prevention, vHC and AdV Phase III trials. We will continue to analyze the data from these studies to understand any variables that may have impacted outcomes or any apparent subpopulation benefits. We thank the patients, investigators and staff who participated in the trials.”

Dr. Brainard continued, “We established pre-planned futility analyses across these three Phase III trials, as each assessed a potentially highly innovative treatment for patients suffering with severe and complex medical conditions lacking significant prior clinical development, and we also expected the trials would require substantial additional capital to bring them to completion. With these current results, we will immediately shift our focus to preserve our substantial remaining capital, review our pipeline and assess strategic options.”

AlloVir will review strategic alternatives for the Company and its portfolio of virus-specific T cell therapies. Such alternatives may include a merger, sale, divestiture of assets, licensing, or other strategic transaction. As of September 30, 2023, AlloVir had cash, cash equivalents and short-term investments of $213.3 million.

About AlloVir’s Earlier Stage Virus-Specific T cell Pipeline : i. Adult Kidney Transplantation: AlloVir has earlier reported the results of its completed Phase II randomized, placebo-controlled trial evaluating posoleucel for the treatment of BKV infection in adult kidney transplant patients. After 24 weeks of treatment, 39% of patients receiving posoleucel experienced a greater than 1-log viral load reduction, compared to 14% of patients receiving placebo. ii Acute Respiratory Infection : The company has completed Part A of a randomized, placebo-controlled Phase 1b/IIa trial with ALVR 106 in 14 stem cell or solid organ transplant patients. ALVR 106 is an investigational, allogeneic, off-the-shelf, multi-virus specific VST therapy candidate designed to target diseases caused by human metapneumovirus (hMPV), influenza, parainfluenza virus (PIV) and respiratory syncytial virus (RSV). Data has been accepted for presentation at a scientific conference in the first quarter of 2024. iii. Chronic Hepatitis B Infection: ALVR 107 is an investigational, allogeneic, off-the-shelf VST therapy designed to target hepatitis B virus (HBV)-infected cells and potentially cure patients with chronic HBV infection. Preclinical and IND-enabling studies support the advancement of ALVR 107 into a clinical proof of concept study as a next step.