The partnership will focus on manufacturing retroviral vectors for off-the-shelf therapies for hematological cancers.
by Millie Hoe, Reporter, BioProcess Insider
July 30, 2025
Biotech company AvenCell Therapeutics has partnered with contract development and manufacturing organization (CDMO) ViroCell Biologics on manufacturing after the latter company's successful delivery of a novel retroviral vector. The vector will be used in production of AVC-203, an off-the-shelf cell therapy engineered to tackle graft-versus-host-disease (GvHD) and graft rejection.
AvenCell’s AVC-203 is a chimeric antigen receptor (CAR) T-cell therapy designed to combat graft rejection. Company CEO Andrew Schiermeier told BioProcess Insider that “AvenCell’s proprietary allogeneic engineering technology involves the application of three sequential edits.”
The first edit knocks out the donor’s endogenous TCR [T-cell receptor] to avoid any possibility of GvHD. The second edit knocks out the expression of MHC [major histocompatibility complex] Class II molecules so that the patient’s CD4 T cells cannot reject the donor cells. The final edit selectively knocks out the donor HLA-A [human leukocyte antigens] molecule from the MHC Class I complex.”
It is the last edit, Schiermeier said, that sets it apart from its competitors. “By leaving in this significant portion of Class I and matching the donor cells’ HLA-B and HLA-C alleles to the patient, the allogeneic cells can fully avoid both T- and NK-cell based rejection.”
Graft rejection is a serious concern in hematological conditions requiring a bone marrow transplant, including blood cancers such as leukemia and lymphoma. It typically occurs when the patient’s own T cells attack transplanted cells. GvHD can be life-threatening; approximately 30-50% of patients receiving hematopoietic cell transplantation developed chronic GvHD, which is a leading cause of late-stage mortality.
To address the manufacturing challenges ViroCell faced when producing the viral vector to carry AVC-203, “it required the development of a bespoke end-to-end manufacturing process,” John Hadden II, CEO of ViroCell, told us, “including the development of a robust seed expansion process developed specifically for the client’s stable packaging cell line, downstream purification process modification, and a new vector filling strategy.”
Allogeneic therapies are gaining rapid favor within the cell and gene therapy (CGT) market, with even veterinary companies producing allogeneic pipelines. With the CGT market set to grow to $28 billion by 2030, fueled in part by innovations in CAR T-cell technology, demand in vectors able to carry complex payloads will only continue to rise.