qCART ^™

Overcomes the Challenges of CAR-T Cell Therapy

Chimeric antigen receptor T (CAR-T) cell therapy represents a major breakthrough in cancer therapy and has produced remarkable clinical responses in certain hematological cancer. However, several obstacles must be overcome before CAR-T cell therapy can be widely applied for many cancers. These include (1) toxicity due to on-target/off-tumor activities and/or cytokine release syndrome (CRS); (2) disease relapses due to: (i) antigen escape and/or antigen heterogeneity of solid tumor, resulting in outgrowth of non-targeted tumor cells and/or (ii) a lack of persistence of CAR-T cells; (3) lack of potency for solid tumors; and (4) high costs associated with CAR-T cell manufacturing.

High levels of T_SCM cells in the CAR T cell population can lead to better clinical outcomes. T_SCM cells exhibit stem-like properties with high capacity for self-renewal, whcih contributes to their long-term persistence. Furthermore, T_SCM cells have the highest therapeutic efficacy due to enhanced metabolic fitness and low level of senescence and exhaustion (Figure 1).

CAR-T cell therapy faces several challenges in the context of solid tumor, including (1) lack of CAR-T cell trafficking to the tumor; (2) antigen heterogeneity of solid tumors; and (3) immunosuppressive tumor microenvironment (TME) which can adversely affect T cell fitness (e.g. differentiation, exhaustion, senescence, and survival). A technological breakthrough needs to be developed to overcome these hurdles.

Viral vector has been widely used for the development of CAR-T cell therapy due to its high efficiency in gene delivery and integration, resulting in stable long-term gene expression. However, CAR-T cells generated virally have several limitations. These include (1) virus-associated safety concerns; (2) limited payload capacity of viral vectors; (3) low expansion capacity and low percentage of CAR⁺ T cells following transduction; (4) low CAR-T cell persistence; and (5) high cost of manufacturing virally-produced CAR-T cells.

A virus-free system can overcome most if not all of these hurdles, but electroporation-associated damages in virus-free systems present a critical challenge. In order for a virus-free system to be effective, we need: (1) a robust gene delivery system; (2) an effective system for integrating multiple genes into CAR-T cells; and (3) a robust cell expansion system for producing clinical-scaled CAR-T cells.

GenomeFrontier has developed Quantum CART (qCART™), a virus-free Quantum Engine™ for developing CAR-T cell therapy that synergistically integrates four platforms:

(1) G-Tailor™: a rapid multiplex gene design, construction, and screening system for designing CAR-T cells with (i) the ability to target to multiple tumor antigens; (ii) modulators for efficient CAR-T cell trafficking and TME resistance; and (iii) a safety control to terminate treatment as needed.

(2) Quantum Nufect™: a robust gene delivery buffer system for introducing therapeutic genes into T cells, resulting in (i) reliable CAR-T cell production while (ii) preserving high cell viability.

(3) Quantum pBac™: a virus-free vector system with (i) a large payload gene integration capacity and (ii) high preference for T_SCM genome integration.

(4) iCellar™: a robust cell expansion system for producing clinical-scaled CAR-T cells with (i) high percentage of CAR⁺ T_SCM cells and (ii) enhanced fitness.

Collectively, qCART™ enables timely (~10 days) and cost-effective manufacturing of clinical-scaled CAR-T cells (1-3.5x10⁹/L) (Table 1, Figure 2 and Figure 3).

Virus-free qCART™ robustly produces clinical-scaled CAR-T cells comprised of high percentage of CAR-T_SCM cells (Table 1) capable of mediating high tumor cytolytic activities (Figure 2).

Virus-free qCART™ reliably produces CAR-T_SCM cells with high expansion capacity against different targets and with various transgene sizes (Table 2), thereby demonstrating the feasibility of multiplex CAR-T construct design.