Valo Therapeutics Aims to Improve Personalized Immunotherapy With a New Tech

Cancer immunotherapy is a multi-directional group of approaches which share the same core principle: tumor is destroyed using the forces of the human immune system. Basically, depending on how the immune system is exploited, cancer immunotherapies are divided into active and passive. 

In case of active immunotherapy, the given treatment aims to stimulate the host’s immune system, so to say “teach” what to attack and enhance the attack. This group of approaches includes cancer vaccines, immuno-modulators and check-point inhibitors. Why is it working in case of cancer? Tumors often have a hostile immunosuppressive microenvironment, so without the additional boost -- the immune system is blind and weak around the tumor, but active cancer immunotherapy tries to address this issue. 

On the other hand, during passive cancer immunotherapy the immune agents are given to patients. This strategy works great with CAR-T cells for blood cancers, having already multiple FDA-approved treatments. Also passive immunotherapies include monoclonal antibodies binding cancer cells, and oncolytic viruses. To look into more details for the last mentioned class -- oncolytic viruses, it is also fair to classify them as both passive and active immunotherapy at the same time. 

At first, the tumor is attacked with the specifically targeted viruses, which causes the cancer cells lysis (breakage of the cell membrane). Consequently, this leads to the local inflammation, where the immune cells are recruited to clean up the mess, and to pick up new antigens in the process. So, after being at first the passively acting viruses, they consequently stimulate active immune response. This ambidextrous mechanism of action is an attractive strategy for so-called “cold tumors” -- the ones which can’t be reached with the immune system without specific interventions. 

The lead program of ValoTx called PeptiCRAd is based on oncolytic adenovirus, loaded with tumor specific peptides. To discuss both sides of the coin, the oncolytic virus strategy in general has a unique mechanism of action, which can target “cold tumors”, induce a strong immune response and effectively destroy the cancer cells. On the other hand, oncolytic viruses are known to be able to induce side effects as a result of activity towards healthy cells. Also, the immune response can be too strong, causing a severe inflammation and an extensive antibody production towards the virus particle itself, consequently neutralizing it.