Periodic Reporting for period 1 - CATCH (Novel T cell therapies against lymphocytic leukaemia)
Reporting period: 2022-07-01 to 2023-12-31
Chronic lymphocytic leukaemia (CLL) is the most common type of leukaemia globally and can rarely be cured. Despite recent advances, the efficacy of promising autologous T cell-based therapies, such as CAR-T technology and bi-/tri-specific antibodies, has been disappointing. This stems from a T cell dysfunction in this disease setting: altered T cell skewing, impaired metabolic plasticity, and disrupted T-cell functioning.
We identified an improved method to activate T cells, which can overcome T cell dysfunction and stimulate an immune response. Prof. Kater has demonstrated superiorly activated T-cells and improved T-cell proliferation via this method.
CATCH will explore the technical and commercial feasibility of the new activation pathway-mediated T-cell activation, through two autologous T-cell technologies – CAR-T and tri-specific antibody technology. These therapeutic strategies have the potential to target and kill CLL cells more effectively, achieve higher remission rates, enable new combination treatments, and provide potentially curative treatments for CLL patients.
To reach proof-of-concept stage, in this project we will:
1) Validate the efficacy of two adapted applications (CAR-T, tri-specific antibody) by achieving T-cell activation and killing target cells in in-vitro CLL samples and live specimens.
2) Perform a thorough IP landscape analysis, establish Freedom-to-Operate, and define an IP strategy.
3) Engage with key stakeholders to gather feedback and advise from key perspectives (patient, clinical, industry), conduct market research to discover potential customers/industrial partners, analyse competitors and identify a feasible roadmap to commercialisation.
4) Formulate a detailed business case to guide the commercialisation of CATCH.
We identified an improved method to activate T cells, which can overcome T cell dysfunction and stimulate an immune response. Prof. Kater has demonstrated superiorly activated T-cells and improved T-cell proliferation via this method.
CATCH will explore the technical and commercial feasibility of the new activation pathway-mediated T-cell activation, through two autologous T-cell technologies – CAR-T and tri-specific antibody technology. These therapeutic strategies have the potential to target and kill CLL cells more effectively, achieve higher remission rates, enable new combination treatments, and provide potentially curative treatments for CLL patients.
To reach proof-of-concept stage, in this project we will:
1) Validate the efficacy of two adapted applications (CAR-T, tri-specific antibody) by achieving T-cell activation and killing target cells in in-vitro CLL samples and live specimens.
2) Perform a thorough IP landscape analysis, establish Freedom-to-Operate, and define an IP strategy.
3) Engage with key stakeholders to gather feedback and advise from key perspectives (patient, clinical, industry), conduct market research to discover potential customers/industrial partners, analyse competitors and identify a feasible roadmap to commercialisation.
4) Formulate a detailed business case to guide the commercialisation of CATCH.
Activity 1: In vitro technical feasibility of CATCH
Milestones:
• M1 - Obtained CAR-T cell constructs
It has been difficult to get the new construct stably overexpressed in T cells. We now have tried different constructs and now have a retroviral construct that leads to expression in primary T cells.
Functional data are to be expected soon.
• M2 - Obtained novel tri-specific antibody constructs
• M3 - Validation of in vitro killing of CLL by CAR-T cells and tri-specific antibodies
• M4 - Validation of cytokine production and production of cytotoxic molecules
• M5 - Validation of in vitro T cell activation and proliferation
We developed a proof-of-concept bispecific antibody directed against xxx epitope and a commonly used epitope that targets the tumor-associated antigen CDxxx. As this bispecific antibody only binds one the epitopes at the effector side, additional stimulation was provided by our generated ‘standard’ antibody. In addition, we designed a proof-of-concept trispecific antibody able to bind two effector-side epitopes and CD19. The bispecific combined with a standard antibody enabled both healthy controls as well as CLL-derived T cells to kill CD19+ target cells. Additional CD28 stimulation further enhanced the cytotoxic potential, reaffirming our previous results. We next performed re-stimulation assays to study activation, proliferation and signs of exhaustion over-time. In these experiments, the bispecific antibody was compared to an antibody in current clinical use (blinatumomab). CLL-derived T cells were used as effectors. Both using the Jeko-1 cell line (not shown) as well as primary CLL cells as targets, the new bispecific resulted in prolonged activation and improved proliferation as compared to blinatumomab. Importantly, improved activation and proliferation did not result in elevated levels of PD-1 expression, as marker of exhaustion.
Similarly, a CD19-directed trispecific antibody also enabled T cells to lyse CD19+ target cells, although at a lower level, likely due to stochastic hindering, which will be tested by modifying the size of the linker.
Activity 2: In vivo technical feasibility of CATCH
• M7 - Survival of NSG mice receiving novel CAR-T cells in vivo
• M8 - Survival of NSG mice receiving tri-specific antibodies
A collaboration with the group of Dr Themeli has been initiated. CLL-like B-cell lines have been selected and are currently transduced to express Luciferase. In vivo growth of these tumors will be established and followed by intervention studies. This part has not yet been completed.
Activity 3: IP position and strategy
• M9 - IP strategy formulated
• M10 - Patent application
A collaboration was initiated with the group of professor Kuball, UMC Utrecht, to enable us to also test the potency of our novel type of stimulation in (A) solid tumors, using Tumor Inflitrating Lymphocytes, (B) not only α/β T cells but also the more rare but potentially tumor-specific γ/δ T cells.
We generated solid preliminary data and now integrated these data with our CLL data into one patent application.
Patent will be submitted before end of April.
Activity 4: Stakeholder engagement and commercial feasibility
• M11 - Market study completed
Market study has been performed and will be uploaded as well.
Activity 5: Establishment of a Business Case
• M12 - Business case developed
• M13 - Go/no go decision
Currently, business plan is being written.
Milestones:
• M1 - Obtained CAR-T cell constructs
It has been difficult to get the new construct stably overexpressed in T cells. We now have tried different constructs and now have a retroviral construct that leads to expression in primary T cells.
Functional data are to be expected soon.
• M2 - Obtained novel tri-specific antibody constructs
• M3 - Validation of in vitro killing of CLL by CAR-T cells and tri-specific antibodies
• M4 - Validation of cytokine production and production of cytotoxic molecules
• M5 - Validation of in vitro T cell activation and proliferation
We developed a proof-of-concept bispecific antibody directed against xxx epitope and a commonly used epitope that targets the tumor-associated antigen CDxxx. As this bispecific antibody only binds one the epitopes at the effector side, additional stimulation was provided by our generated ‘standard’ antibody. In addition, we designed a proof-of-concept trispecific antibody able to bind two effector-side epitopes and CD19. The bispecific combined with a standard antibody enabled both healthy controls as well as CLL-derived T cells to kill CD19+ target cells. Additional CD28 stimulation further enhanced the cytotoxic potential, reaffirming our previous results. We next performed re-stimulation assays to study activation, proliferation and signs of exhaustion over-time. In these experiments, the bispecific antibody was compared to an antibody in current clinical use (blinatumomab). CLL-derived T cells were used as effectors. Both using the Jeko-1 cell line (not shown) as well as primary CLL cells as targets, the new bispecific resulted in prolonged activation and improved proliferation as compared to blinatumomab. Importantly, improved activation and proliferation did not result in elevated levels of PD-1 expression, as marker of exhaustion.
Similarly, a CD19-directed trispecific antibody also enabled T cells to lyse CD19+ target cells, although at a lower level, likely due to stochastic hindering, which will be tested by modifying the size of the linker.
Activity 2: In vivo technical feasibility of CATCH
• M7 - Survival of NSG mice receiving novel CAR-T cells in vivo
• M8 - Survival of NSG mice receiving tri-specific antibodies
A collaboration with the group of Dr Themeli has been initiated. CLL-like B-cell lines have been selected and are currently transduced to express Luciferase. In vivo growth of these tumors will be established and followed by intervention studies. This part has not yet been completed.
Activity 3: IP position and strategy
• M9 - IP strategy formulated
• M10 - Patent application
A collaboration was initiated with the group of professor Kuball, UMC Utrecht, to enable us to also test the potency of our novel type of stimulation in (A) solid tumors, using Tumor Inflitrating Lymphocytes, (B) not only α/β T cells but also the more rare but potentially tumor-specific γ/δ T cells.
We generated solid preliminary data and now integrated these data with our CLL data into one patent application.
Patent will be submitted before end of April.
Activity 4: Stakeholder engagement and commercial feasibility
• M11 - Market study completed
Market study has been performed and will be uploaded as well.
Activity 5: Establishment of a Business Case
• M12 - Business case developed
• M13 - Go/no go decision
Currently, business plan is being written.
we also obtained relevant information on the potential benefit of our stimulation beyond CLL:
We provide evidence that tumor infiltrated lymphocytes of colorectal carcinoma, that have poor responses to T-cell directed therapies, are also better activated upon this alternative stimulation, resulting in a significant increase in proliferation
In addition, we now show that improved function of alphabeta T cells is also recapitulated in gamma delta T cells, which is a subtype of T cells that are considered highly relevant for cancer immunotherapy.
We provide evidence that tumor infiltrated lymphocytes of colorectal carcinoma, that have poor responses to T-cell directed therapies, are also better activated upon this alternative stimulation, resulting in a significant increase in proliferation
In addition, we now show that improved function of alphabeta T cells is also recapitulated in gamma delta T cells, which is a subtype of T cells that are considered highly relevant for cancer immunotherapy.