Mesothelioma presents quite a few obstacles for the people with this cancer and the doctors trying to help them. One of the most significant hurdles? How advanced — and untreatable — mesothelioma often is at the time of diagnosis.
A therapy currently in testing might be the solution to this problem.
Targovax, the maker of the treatment ONCOS-102, announced promising clinical study results last week via press release. These successes are follow-ups to the reported outcomes from three months ago, when the company offered hope for late-stage pleural mesothelioma patients.
Why We Need Better Late-Stage Mesothelioma Treatment
Each year, there are approximately 3,000 new mesothelioma cases. Most of them involve a late-stage (stages 3 or 4) diagnosis, which means patients first learn of their disease when it’s already sizable.
According to the Journal of Thoracic Oncology, around 68% of patients are diagnosed with late-stage mesothelioma. At this point, the cancer is usually too widespread to stop with surgery. Chemotherapy and radiation can slow down the disease — but often won’t stop it permanently.
How ONCOS-102 Stops Late-Stage Mesothelioma
The ONCOS-102 clinical trial is designed to test the treatment against late-stage mesothelioma. The group that received ONCOS-102 — combined with chemotherapy — was comprised mostly of stage 3 and stage 4 patients. The comparison group, which received only chemotherapy, involved early-stage patients.
According to Targovax’s press release, 20 patients have now received ONCOS-102 plus chemotherapy. The Norway-based company said that progression-free survival for the ONCOS-102 participants is similar to the initial report of around nine months. The disease control rate was around 90%.
Progression-free survival means the disease has not grown or spread since the treatment began. In the findings reported in January, the chemotherapy-only participants had progression-free survival of approximately seven months and disease control rate of 83%.
In summary, the late-stage mesothelioma patients showed more survival benefits and disease response than the early-stage patients did. The reason appears to be ONCOS-102 — and how it helps the immune system.
What Is ONCOS-102?
ONCOS-102 is essentially a combination of virotherapy and immunotherapy. It’s an adenovirus armed with immune system-stimulating proteins. The proteins, called cytokines, signal to the immune system to activate and find diseased cells.
This treatment kills mesothelioma tumors in two ways:
- The adenovirus replicates and breaks up the cells.
- Once released, the proteins signal to the immune system that cancer is present.
The adenovirus is injected into the tumor site, where ONCOS-102 replicates until it breaks apart the diseased cells. The virus only targets mesothelioma cells — and leaves healthy ones alone.
Once a cell breaks up, the adenovirus releases the cytokines. They alert the immune system’s T-cells, which are the body’s primary defenders against cancer.
However, T-cells have difficulty identifying the mesothelioma cells as intruders. They look for “antigens”, which are molecules that trigger an immune system response.
Typically, these antigens are held within the mesothelioma cells. They’re hidden from the T-cells, which cannot identify mesothelioma as dangerous. ONCOS-102 releases these antigens and gives the T-cells evidence of mesothelioma — and an example of what to look for.
The T-cells now have the knowledge to identify diseased cells. Targovax published a video explaining how the T-cells use this information.
“The activated T-cells start to circulate in the body in search of cancer cells,” the video’s narrator says. “When a T-cell encounters a cancer cell expressing the particular tumor antigens it has been activated to recognize, it darts to the cancer cell and secretes powerful enzymes which kill the cancer cell.”
What’s Next? ONCOS-102 Paired With Immunotherapy
The ONCOS-102 experiment for mesothelioma may soon come to the United States. Company officials said the next phase of the study could involve pairing the therapy with an immunotherapy drug. Researchers hope this combination enhances the immune system even further.
T-cells have PD-1 receptors, while mesothelioma cells have PD-L1 receptors. When they connect, the T-cells are tricked into thinking mesothelioma cells are safe. The PD-1/PD-L1 link disguises the cancer.
Targovax officials plan to use a checkpoint inhibitor, such as pembrolizumab (Keytruda) or nivolumab (Opdivo). These drugs block the interaction between two proteins, PD-1 and PD-L1.
If you’re a mesothelioma patient and interested in this clinical trial — or another study — we can help connect you. Email our patient advocate and registered nurse, Jenna Campagna, at email@example.com to learn more about the available trials.
Show Sources & Author
- Targovax Releases Update for Mesothelioma Trial Combining ONCOS-102 and Chemotherapy. BioSpace. Retrieved from:
https://www.biospace.com/article/releases/targovax-releases-update-for-mesothelioma-trial-combining-oncos-102-and-chemotherapy/. Accessed: 05/04/2020.
- Mesothelioma Tumors Respond to ONCOS-102 Plus Pemetrexed and Cisplatin. Targeted Oncology. Retrieved from:
https://www.targetedonc.com/view/mesothelioma-tumors-respond-to-oncos-102-plus-pemetrexed-and-cisplatin. Accessed: 05/04/2020.
- Targovax ASA Webcast. Royalcast. Retrieved from:
https://channel.royalcast.com/hegnarmedia/#!/hegnarmedia/20200121_1. Accessed: 01/28/2020.
- ONCOS-102. Immuno-Oncology News. Retrieved from:
https://immuno-oncologynews.com/oncos-102/. Accessed: 01/28/2020.
- ONCOS -102 Mechanism of Action. YouTube. Retrieved from:
https://www.youtube.com/watch?time_continue=32&v=K_PfmBpa38A&feature=emb_title. Accessed: 01/28/2020.
- ONCOS – Oncolyctic Virus. Targovax. Retrieved from:
https://www.targovax.com/en/oncos-oncolyctic-virus/. Accessed: 01/28/2020.