VST – Our Core Platform

Virus-Specific T Cell (VST) Platform

VST

Many cancers, including nasopharyngeal carcinoma and cervical carcinoma, are associated with specific viral infections1.  The virus hides within the host’s cells and causes changes that eventually lead to the formation of a tumor. Although difficult for the immune system to detect, the virus displays some of its proteins on the surface of the tumor. These virus antigens make prime targets for our VST platform therapy.

Living Treatment

Unlike chemotherapy or conventional medications, our VST therapy is a living treatment which is based on each patient’s individual and unique immune system. The patient receives T Cells that are alive, functional and able to react to the cancer. This treatment has produced persistent, durable and long lasting anti-tumor effects in patients.

Why is Tessa’s VST Platform safe & successful?

Tessa Therapeutics’ VST platform has shown clinical safety and efficacy in treating solid tumors2.
This can be attributed to the following characteristics exhibited by VSTs:

1. Target Specificity
– Limited Toxicity

Virus antigens are good targets for cancer treatment as they are specifically expressed on virus-associated cancers but not on healthy tissues. VSTs are specific for these virus antigens, leading to minimal collateral damage on healthy cells and consequently minimal toxicities. This benefit is reflected in significantly less side effects or complications in patients receiving VSTs.

2. High Tumor Penetrance
– Better Efficacy

VSTs possess the biological qualities that allow them to penetrate the immune-suppressive tumor microenvironment. Mimicking the natural way in which the body’s immune system responds to a viral infection, VSTs recognize and attack virus-associated cancer cells. Pore-forming proteins called perforin will be released by VSTs, which punches holes in the target cell membrane. Another type of proteins called granzymes can then enter the target cell to induce apoptosis – a mechanism that causes the cancer cell to self-destruct.

3. Polyclonality
– Lower Chance of Tumor Escape

Our VST platform allows for the organic growth and stimulation of polyclonal VSTs which display a wide range of T Cell receptor antigen affinities. The ability of these VSTs to address multiple peptides of the virus-associated cancer antigen, limit the cancer’s ability to evolve away from being detected.

4. Memory and Durability
– Stronger Persistence

VSTs that are generated using our proprietary platform exhibit qualities of memory and durability. VSTs can self-renew, re-activate and expand when encountering a virus-associated cancer antigen. This sustained and durable response is reflected in published scientific literature that suggests VSTs can persist in the body for up to 10 years post-infusion3.

1. Parkin DM. Int J Cancer. 2006 Jun 15;118(12):3030-44
2. Chia W-K et al Mol Ther 2014 22:132-139
3. Cruz et al., Cytotherapy. 2010 October;12(6):743–749

Epstein-Barr Virus-Specific T Cells (EBVSTs)

EBVSTs

Using our proprietary Virus-Specific T Cell (VST) platform, we are able to target specific Epstein-Barr Virus (EBV) proteins that are present on EBV-positive tumors. Cancers associated with EBV include Burkitt’s lymphoma, non-Hodgkin’s lymphomas, Hodgkin’s disease, nasopharyngeal carcinoma, gastric carcinoma, lymphoepithelioma-like carcinomas, and immunodeficiency-related leiomyosarcoma4.

Our EBVST Production

  1. Peripheral Blood Mononuclear Cells (PBMCs) are isolated from the patient’s blood.
  2. The PBMCs are then stimulated with autologous Lymphoblastoid Cell Lines that express EBV antigens to generate EBVSTs.
  3. The activated EBVSTs are then expanded till there are billions of them.
  4. These activated EBVSTs are then harvested, comprehensively tested for safety and potency, before being infused back into the patient where they destroy cancer cells that display these EBV antigens.

4. Hsu JL, Glaser SL. Crit Rev Oncol Hematol. 2000 Apr;34(1):27-53.

We are extending our proprietary Virus-Specific T Cell platform to treat other virus-associated cancers.

Human Papillomavirus-Specific T Cells (HPVSTs)

HPVSTs

We are extending our proprietary VST platform to treat other virus-associated cancers. Cervical carcinoma and oropharyngeal carcinoma are two cancers strongly associated with human papillomavirus (HPV) infection.

Our HPVST Production

  1. Peripheral Blood Mononuclear Cells (PBMCs) are isolated from the patient’s blood.
  2. The PBMCs are then stimulated with antigen loaded dendritic cells that express HPV antigens to generate HPVSTs.
  3. The activated HPVSTs are then expanded till there are billions of them.
  4. These activated HPVSTs are then harvested, tested for safety and potency, before being infused back into the patient where they destroy cancer cells that display these HPV antigens.