Immunotherapy with oncolytic virus Shows Promise for Mesothelioma
By Warren Miller. 11th Febuary 2020
Immunotherapy is at the forefront of future treatment options for Malignant Pleural Mesothelioma patients.
Within this field is oncolytic viruses therapy which can be used to target specific cells, they infect the Mesothelioma tumour cells and boost pre-existing native immune response. The viruses can kill cells that are not protected by the immune system.
The injection of oncolytic viruses directly into the tumour also has a lower rate of side effects such as pneumonitis, pancreatitis, and colitis which can limit therapy options for certain mesothelioma patients.
A new study by Scandinavian clinical stage immuno-oncology company, Targovax has combined an Oncolytic virus therapy vaccine with certain chemotherapy drugs - pemetrexed and cisplatin - and has produced encouraging results. The vaccine, known as ONCOS-102, helped mesothelioma chemotherapy work better.
ONCOS-102 is a scientifically engineered, immune system activator and is made out of an altered human adenovirus, designed to seek out mesothelioma cells.
Adenoviruses are responsible for most human respiratory illnesses, they are common viruses that cause a range of illness such sore throat, bronchitis, pneumonia and diarrhea.
When the ONCOS-102 virus enters the mesothelioma cells, it replicates itself many times over, and places the immune system on high alert.
Oncolytic Combination therapy v Chemotherapy Mesothelioma Trial
In the trial, 31 patients with Malignant Pleural Mesothelioma volunteered. 20 of the patients received the combination therapy of ONCOS-102 and chemotherapy. With 11 patients in the control group receiving only chemotherapy. ONCOS-102 was given by injection in this study on days 1, 4, 8, 36, 78 and 120. The chemotherapy mix of pemetrexed and cisplatin was administered in 21-day cycles starting on day 22 of treatment.
- 90% of patients receiving the immunotherapy vaccine with chemotherapy responded to the treatment on some level
- With 30% the mesothelioma tumours had either shrunk or disappeared
- In the remaining 60%, the mesothelioma was stable
- The mesothelioma was also stopped from progressing for an average of 8.9 months
- In the chemotherapy-only group, the mesothelioma tumours came back in 6.8 months
Pathologists examined samples from the mesothelioma tumours of 15 of the patients in the ONCOS-102 group. 10 had a large increase in CD8+ T cells. 9 also had more PD-1 protein in their bodies. The results suggest that a checkpoint inhibitor to regulate PD-1 might improve ONCOS-102 response.
Professor Paz-Ares, Principal Investigator of the trial and current Chair of the Medical Oncology Department in a Madrid hospital said:
“ Mesothelioma remains a challenging disease with generally poor prognosis, and there is a large unmet medical need for new, innovative treatments such as ONCOS-102. We generally consider antitumor response difficult to measure in mesothelioma, and PFS may be the preferred early indicator of clinical efficacy. Although the data are preliminary and still maturing, it is encouraging to see signals of numerically improved median PFS in the ONCOS-102-treated group. The ORR in first line patients is as expected relative to historical control, whereas the DCR is higher than we normally see. We are continuing to follow the patients and it will be very interesting to track how the data matures over time. ”