Immunofusion is a biotechnology company, founded in 2018. The company focused on the discovery, development, and commercialization of synthetic DNA products for cancer and infectious diseases immunotherapy. Our company develops a number of innovative drug designs including DNA vaccines, immunocytokines, genetic modifications and CAR-T cell therapy.
Problem. Number of FDA approved anti-CD19 CAR T-therapies for refractory/relapsed B-cell lymphomas have demonstrated remarkable potency with 40-80% complete response rate. Meanwhile, there are some major limitations of currently available commercial products: on-target off-tumor (healthy B-cells) activity resulted in B-cell aplasia and hypogammaglobulinemia; antigen escape (loss of CD19 expression by tumor cells) with subsequent TAA-negative relapse; CAR T-cell exhaustion and senescence as two main hurdles on the way to tumor control and full eradication.
Solution. We have developed the fourth generation tandem CAR which exclusively recognizes patient specific tumor associated antigens on CLL or MCL cells, sparing normal B cells. These patient specific antigens could be matched in up to 70% of MCL and 50% of CLL. VHH\scFv specific to these patient specific antigens on MCL and CLL is incorporated in tandem CAR with ROR1-specific proprietary huminized VHH and is balanced for effector function, exhaustion and persistence. Our CAR design has been developed to be resistant to functional exhaustion by exploiting fine-tuned intracellular signaling domains.
Stage of the development. In vitro proof of concept revealed excellent cytotoxicity and specificity characteristics for prototype CARv1 and CARv2 T-cells against CLL patient’s blasts positive for protein X. We are in the process of novel binders selection and validation from the proprietary synthetic nanobody library.
Next stage. Tandem CAR with the novel Nanobody binders in vitro analysis, patent application filling.
Cancer DNA vaccines
Problem. Numerous cancer vaccines have gone through clinical trials, showing the potential for immunization against tumor-associated antigens, which has often led to clinical response and improved patient survival. The first FDA-approved in 2010 cell-based cancer vaccine Sipuleucel-T showed a significant improvement in overall patient survival. Since then, the development of cancer vaccines has advanced, including with the advent of the DNA/RNA platform for recombinant vaccines. Despite the variety, antitumor vaccines some limitations:
DNA vaccines usually have lower immunogenicity; the immune response may be skewed towards Th2 and not effective enough against the tumor; short-term immune response due to lack of T-help; inefficient T cell priming due to lack of targeted antigen delivery to dendritic cells in vivo, or use of inappropriate DC population ex vivo; low frequency of known tumor-associated antigens in some types of tumors.
Value Proposition. We have developed a series of DNA vaccine preparations for immunization against tumors, including prostate cancer. The protein construct includes a dendritic cell targeting unit, one of several tumor-associated antigens, and an immunostimulatory protein. The genetic constructs were optimized for the best expression and secretion of the fusion antigen protein. Several tumor-associated antigens are included in the vaccines, such as PSA, PAP, PSMA and NY-ESO1 for prostate cancer. We also invented a multi-epitope form of the vaccine, combining several antigens with coverage of a wide range of tumors. We are testing our vaccine with different DNA delivery options, including electroporation, needleless injection, and systemic immunization by intravenous administration of lipid nanoparticles. We have shown a high immunogenicity of a number of vaccine candidates expressed in the antibody and cellular immune response in mice. Pre-clinical testing of the effectiveness of vaccine candidates in a syngeneic tumor mouse model is underway.
Stage of the development. Nearly a hundred experimental DNA vaccine constructs have been assembled and tested for expression and secretion efficiency to select the best candidates. A series of experiments was carried out to test the immunogenicity of DNA vaccines in mice. We have achieved a strong immune response determined by very high antibody titers, production of interferon gamma by T-cells on antigenic stimulation and a cytotoxic immune response against tumor.
Next stage. Preclinical testing of the therapeutic effect of the vaccine, delivered by electroporation and needle-free injection, on syngeneic tumor mouse models; preclinical evaluation of the effectiveness of therapeutic vaccination of systemic injection of DNA-lipid nanoparticles; final testing of the best vaccine design and delivery method in humanized mouse PDX models with Transcure LLC.
Problem. There are a lot of reasons why different immunotherapeutics do not work in solid tumors. One reason is a hostile tumor microenvironment, that precludes CD8 T-cell homing, abolishes their effector functions and causes exhaustion, induces CD4 Treg cells, DCreg. That’s the reason for poor results of cancer vaccines and cellular therapies (e.g. CART cell) in solid tumors. Pharmacokinetics of anticancer drugs is also an obstacle for efficient immunotherapy. Only 0.1% of recombinant cytokines and CAR-T cells reach the TME of a solid tumor.
Value Proposition. We have developed a platform of nucleic acid based targeted delivery (mRNA or DNA) of cytokines and other immune activating molecules to the tumor tissue (prostate cancer, lung cancer, bladder cancer, PDAC, breast cancer). Every immunocytokine biomolecule consists of a targeting unit (scfv or VHH) specific to a tumor associated antigen, interleukin and a costimulatory molecule. The treatment modality assumes an exposure to 4 different immunocytokines simultaneously, each fulfilling its own but complementary function. The main function is to accomplish DC homing and maturation in the tumor microenvironment (TME), homing of T-cell and NK-cells to TME and activate different chains of the immune system directly in the immunosuppressive TME. Such therapeutic approach could be an independent treatment modality to release all pathways of endogenous anticancer immunity as well as an additive therapy to any cellular therapy (CAR-T cells, NK cells) or cancer vaccine to enhance the anticancer efficacy. Nethertheless, our platform is based on delivery of all immune activating molecules integrating all chains of anticancer immunity for treating any TAA expressing targeted solid cancer.
Stage of the development. Four designed targeted molecules were tested In vitro. They proved a high magnitude of predicted biological activity. For example, recombinant protein IF3 targeting B7H3, and carrying several immunostimulatory domains demonstrated prominent in vitro activity. Now we are carrying out in vivo testing in humanized mouse PDX models jointly with Transcure LLC.
Next stage. Checking out different gene delivery platforms of our molecules and selection of the best variant for future clinical studies. Investigation of the best combination and a time lapse sequel of our 4 designed targeted molecules in vivo in humanized mouse PDX models jointly with Transcure LLC. Investigation of dynamic changes in tumor microenvironment by such techniques as Nanostring RNA, flow cytometry, CYTOF, IHC and etc before and after immunotherapy. Patent application; EMA/FDA expertise including gene and cellular therapy issues. Phase I/II clinical trials implementation.
SARS-CoV-2 DNA vaccine
Problem. Multiple SARS-CoV-2 vaccines based on different platforms are being developed at an unprecedented speed and are currently on the market. Despite the good efficacy (more than 90% for some platforms), they have a number of limitations: duration and complexity of production for inactivated and viral vector-based vaccines contributes to the price; harsh vaccine supply chain requirements for RNA vaccines; set of antigens is limited to the highly mutable SARS-CoV-2 S-protein for RNA, protein subunit, and vector-based vaccines; the T-cell response is narrowed only to the structural proteins of SARS-CoV-2, but not to the most conservative virus replication machinery proteins; immunogenecity of viral vectors decreases response to the additional administration; VOC diminished antibody neutralization response and clinical activity.
Value Proposition. A DNA vaccine, which includes two components: DNA-encoded virus-like particle for strong antibody response including all the variants of concern (VoC) and a scaffold protein with the number of T-cell epitopes. Rational design of T-cell epitopes that are conservative for all beta-coronaviruses provides long-lasting T-cell immunity for all the strains, including SARS-CoV-1, SARS-CoV-2 and VOC. Thus, cross-over antiviral immunity (pan-coronavirus vaccine) is ensured. Due to its nature DNA vaccine is predicted to be safer, highly stable and could be produced in large quantities for low costs.
Stage of the development. In silico design and in vitro analysis of B- and T-cell components were carried out, confirming high levels of recombinant proteins production. Antibody eliciting components could form a virus-like particle structure in a culture medium. High antibody titers were observed in mice and rabbits after vaccination with the various delivery methods (DNA-polymer conjugate, needle-free injection system, electroporation). Proprietary vectors and formulations for enhanced needle free and virus free DNA delivery have been developed. The presence of a T-cell response of the Th1 type (production of interferon gamma) was observed for the T-cell component that contains pan-coronavirus epitopes.
A patent application is filed.
Next stage. Complete line of preclinical vaccine safety and efficacy trials, preparation for clinical trials.
SARS-CoV-2 Omicron Neutralization Antibody
Problem. Therapeutic neutralizing antibodies constitute a key short-to-medium term approach to tackle COVID-19. The emergence of SARS- CoV- 2 variants threatens current vaccines and therapeutic antibodies and urgently demands powerful new therapeutics that can resist viral escape. The last outbreak of the Omicron (B.1.1529) variant abrogated the majority of the FDA-authorized antibody treatments. Despite the lower mortality rate from the Omicron variant, its antibody treatment is still in high demand especially for immunosuppressed patients.
Value Proposition. By screening of the extra-large proprietary synthetic humanized VHH antibody library we have identified a number of nanomolar-range affinity receptor binding domain (RBD) binders. Importantly, their affinities are weakly influenced by SARS-CoV-2 variant of concern (VoC) mutations. Two lead candidates are developed. One is the VHH binder in a form of IgG1 Fc-fusion (monoVHH). Second is the avidity enhanced original VHH binder (triple tandem) in a form of IgG1 Fc-fusion (tripleVHH). Affinities for monoVHH and tripleVHH against Beta, Delta, and Omicron were determined in low-nanomolar and low-picomolar ranges respectively. The plaques reduction neutralization test revealed IC50 in 10-100 ng\ml range for Omicron BA.1 variant. Therefore, these VHH antibodies have a promising therapeutic potential for present and future SARS-CoV-2 variants.
Stage of the development. Preclinical in vitro, patent application filling.
Next stage. Preclinical in vivo, partnership.
Dormeshkin Dmitri, PhD
Head of Protein Engineering Department
Katsin Mikalai, MD
Chief Scientific Officer
Alexander Meleshko, PhD
Head of Preclinical Models and Cancer Vaccines Unit
Head of Cellular Engineering Department