Platform for Endogenous Protein Knockout for Enhanced CAR-T Therapy

Background & Unmet Need

• Chimeric Antigen Receptor (CAR)-T cell therapy is an immunotherapy wherein T cells are collected from patients and engineered to express CARs, which recognize and target specific tumor antigens
• This type of therapy has shown promising results for blood cancers, with seven therapies approved since the first CAR-T approval in 2017 (for Acute Lymphoblastic Leukemia)
• However, CAR-T therapies lack efficacy in solid tumors in part due to interactions with the tumor microenvironment (TME), which rapidly suppresses and eliminates T cell anti-tumoral activity
• For example, binding of PD-L1 to PD-1 on CAR-Ts can suppress T-cell functions, including proliferation, cytokine production, and cytolytic activity, leading to immune escape
• Unmet Need: Enhanced methods of CAR-T therapy that facilitate T cell expansion and function in the presence of the immunosuppressive TME

Technology Overview

• The Technology: Integration of Protein Knockout (PKO) technology with cell therapy, such as CAR-T therapy, to enhance expansion and efficacy
• The Discovery: PKO is a method that reduces or inactivates a target protein by genetically linking a small targeting peptide to E3 ubiquitin ligase β-TrCP
• PKO can be integrated into the same vector as therapeutic proteins, such as CARs, in cell therapy  to selectively eliminate endogenous proteins which hinder therapeutic efficacy
• PoC Data: As a proof of concept, PKO was used to selectively degrade endogenous PD-1 in CAR T-cells, which is known to suppress T cell function
• Transduction of primary human T-cells with the experimental vectors effectively reduced PD-1 expression and intensity and improved CAR-T expansion even in the presence of PD-L1
• CAR expression on the cell surface was not affected by PKO integration

Technology Applications

• Treatment of solid tumors (e.g., lung, breast, colon, colorectal, melanoma) that overexpress ART1
• Can be used alone or in combination with other immune checkpoint inhibitor therapies or chemotherapies

Technology Advantages

• PKO reduces but does not completely eliminate target genes, allowing for baseline expression in cases where complete knockout can be detrimental
• PKO and therapeutic genes can be incorporated into the same vector, allowing for streamlined delivery
• May reduce costs, side effects, and patient burden by eliminating the need for anti-PD-1 medications in addition to CAR T-cell therapy