Altered Viruses May Help Boost Immunotherapy for Malignant Mesothelioma

Viruses may soon be playing a bigger role in the fight against malignant mesothelioma and other thoracic cancers.

A pair of biologists from Minnesota say there is evidence that, in addition to killing mesothelioma cells directly, specific kinds of altered viruses might help make mesothelioma immunotherapy treatment more effective.

How Does Immunotherapy Work?

Like many other types of cancer, mesothelioma tumors are able to grow unchecked in part by “hiding” from the immune system.

Immunotherapy relies on a variety of different substances that stimulate the immune system and allow it to recognize enemies such as mesothelioma cells. Immunotherapy is considered one of the most important and promising methods for fighting many types of cancer, including pleural mesothelioma.

In some cases, immunotherapy with drugs such as Keytruda (pembrolizumab) and avelumab have dramatically slowed or even stopped the growth of pleural mesothelioma tumors. Unfortunately, only a small percentage of mesothelioma patients are responsive to immunotherapy.

According to Dr. Alexander Dash of Macalester College in St. Paul, Minnesota and Dr. Manish Patel with the University of Minnesota, researchers are now working to develop combination therapies “that would expand the range of patients who will respond to and benefit from immune therapy.”

Viroimmunotherapy is one such combination therapy.

Fighting Mesothelioma with Viruses

Virotherapy relies on the use of oncolytic viruses – viruses that have been altered to seek out and destroy cancer cells while sparing normal tissue. The technique has shown promise as a stand-alone cancer treatment.

But in their article “Viroimmunotherapy of Thoracic Cancers” in a recent special issue of Biomedicines, Dash and Patel say that viruses, like immunotherapy agents, can also be used to jumpstart the immune system to fight thoracic cancers like mesothelioma.

“In pre-clinical models of different thoracic cancers, it has been found that these viruses can induce immunogenic cell death, increase the number of immune mediators brought into the tumor microenvironment and broaden the neoantigen-specific T cell response,” they write.

In other words, certain oncolytic viruses can function like immunotherapy drugs and may be able to augment the effect of these drugs when used in combination treatments for aggressive cancers like pleural mesothelioma.

At present, there is no cure for mesothelioma. Even with the best treatments available, most mesothelioma patients die within a year of diagnosis. Despite heavy regulation of asbestos in the US, the number of mesothelioma cases has held relatively steady at about 2,500 per year for decades.

Source:

Dash, AS, Patel, MR, “Viroimmunotherapy of Thoracic Cancers”, 2017, Biomedicines Special Issue