LOAd703 is an oncolytic virus that is currently being investigated in clinical trials as a potential treatment of various solid tumors. It is a type of adenovirus, or “common cold” virus, modified to infect and replicate inside cancer cells but not healthy cells.

Being developed by Lokon Pharma, LOAd703 has shown promising anti-tumor responses in experimental cancer models.

How LOAd703 works

LOAd703 is an immunostimulatory oncolytic virus, meaning a virus that has been modified to include additional genes known to stimulate the immune system. LOAd703 is designed to, once administered, infect cancer cells and start making the proteins encoded by those additional genes in the tumor microenvironment. These proteins activate an immune response against cancer.

In other words, LOAd703 is designed to work by modulating the tumor microenvironment, and by simultaneously activating the immune system to attack tumor cells. (The tumor microenvironment consists of the connective tissue, blood vessels, and inflammatory cells found between malignant cells and normal host tissues.)

LOAd703 in clinical trials

Experimental early studies in mice, dogs, and people have shown that LOAd703 can be effective in treating cancer.

A study published in the scientific journal Cancer Research showed that LOAd703 initiated a robust anti-tumor immunity and was effective in eradicating pancreatic cancer in experimental models.

Another study published in the scientific journal Clinical Cancer Research revealed that in in vivo models, LOAd703 was effective in reducing established tumors. The study also revealed that LOAd703 worked as a potent immune activator that modulated the tumor stroma (connective and other tissues that aid tumor growth) and supported anti-tumor responses.

Based on these promising results, the effectiveness of LOAd703 in treating cancer is currently being investigated in clinical trials.

The safety of LOAd703 is being evaluated in a Phase 1/2a clinical trial (NCT02705196) in patients with pancreatic cancer. The study also aims to establish whether the injection of LOAd703 directly into the tumor is effective in supporting current standard of care treatment to reduce the size of the tumor and improve survival. The trial is currently recruiting about 26 patients at two sites in Houston, Texas.

A Phase 1/2 trial (NCT03225989) evaluating the effect of LOAd703 in patients diagnosed with different types of solid cancers — pancreatic, biliary, ovarian and colorectal — is also underway. This study’s primary outcome is to measure the toxicity and tolerability of LOAd703. Secondary goals include measuring the response of tumor size following treatment, overall survival of patients, time to cancer progression, and progression-free survival. The study is currently recruiting up to 50 cancer patients in Sweden, who will be treated with LOAd703 as an add-on to standard of care treatment, such as immune conditioning chemotherapy.


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