NEW YORK – When cancer patients have a useless tumor, treatment options can be extremely limited – if not impossible. New research offers hope for patients who master such devastating conditions. Doctors at NYU Langone Health say a new virus therapy offers hope to patients without a surgical option. In clinical trials, a cold virus, combined with an immunotherapeutic agent, infects and kills cancer cells.
Study authors say this is one of the first experiments to prove that oncolytic viruses can safely promote existing cancer therapies. Currently, immunotherapies that help the human immune system to kill cancer cells can only shrink tumors in a third of patients.
The new virus combination injects patients with an experimental drug created using a coxsackie virus, V937. Patients also receive pembrolizumab, a drug for immunotherapy, also known as pembro or Keytruda. Thirty-six men and women participated in the trial and received the treatment every few weeks for a minimum of two weeks.
The combined treatments successfully shrunk melanoma tumors in 47 percent of these patients. In addition, eight of the patients using both drugs had complete remission of cancer, with no signs of skin cancer.
“Our initial results from the study are very promising and show that this oncolytic virus injection, a modified coxsackie virus, in combination with existing immunotherapy is not only safe, but that it has the potential to work better against melanoma than immunotherapy alone,” says senior investigator and medical oncologist. Dr. Janice Mehnert, in a media statement.
Serious side effects remain
Study authors note that the experimental treatment has some striking side effects, both mild and severe. Most participants developed mild reactions, such as rash or fatigue. However, 13 patients (36%) experienced severe immune reactions in the liver, stomach or lungs. According to researchers, these reactions also occur in cancer patients who use pembrolizumab alone.
Mehnert, a professor at the NYU Grossman School of Medicine, warns that more tests are needed before this combination becomes the “standard of care” for people with advanced melanoma. She adds that the hearings are already underway.
The next phase of testing will include melanoma patients experiencing the widespread growth of their cancer. Researchers will also work with patients whose tumors, if successfully reduced by virus therapy, can be removed by surgery.
The addition of viruses increases the results of immunotherapy
The study found patients who responded least to immunotherapy treatments alone responded best to the new combination. Those with the best treatment results had less PDL1 on the surface of their cancer cells. Pembrolizumab usually blocks these chemical receptors. Study authors are now understanding how V937 alters the molecular composition of the tissues around tumors.
“Our goal is to determine whether the virus changes the tumor environment from ‘friendly’ to ‘unfriendly’, which makes the cancer cells more vulnerable to pembrolizumab, ‘Mehnert concludes.
The researchers present their findings at the annual meeting of the American Association for Cancer Research in April.