NEW YORK — When cancer patients have an inoperable tumor, treatment options can be extremely limited — if not impossible. New research is offering some hope for patients batting such devastating circumstances. Doctors at NYU Langone Health say a new virus therapy is offering hope to patients without a surgical option. In clinical trials, a common cold virus combined with an immunotherapy drug infects and kills cancer cells.
Study authors say this is one of the first experiments to prove oncolytic viruses can safely boost existing cancer therapies. Currently, immunotherapies which help the human immune system kill cancer cells only successfully shrink tumors in a third of patients.
The new virus combo injects patients with an experimental drug created using a coxsackievirus, V937. Patients also receive pembrolizumab, an immunotherapy drug also known as pembro or Keytruda. Thirty-six men and women participated in the trial, receiving the therapy every few weeks for a minimum of two weeks.
The combined treatments successfully shrank melanoma tumors in 47 percent of these patients. Moreover, eight of the patients taking both drugs went into complete cancer remission with no signs of their skin cancer.
“Our initial study results are very promising and show that this oncolytic virus injection, a modified coxsackievirus, when combined with existing immunotherapy is not only safe but has the potential to work better against melanoma than immunotherapy alone,” says study senior investigator and medical oncologist Dr. Janice Mehnert, in a media release.
Serious side-effects remain
Study authors note the experimental treatment does have some noticeable side-effects, both mild and severe. Most of the participants developed mild reactions, such as a rash or fatigue. However, 13 patients (36%) experienced serious immune reactions in the liver, stomach, or lungs. Researchers say these reactions also occur in cancer patients taking pembrolizumab alone.
Mehnert, a professor at NYU Grossman School of Medicine, cautions that more testing is necessary before this combination becomes the “standard of care” for people with advanced melanoma. She adds those trials are already underway.
The next phase of testing will involve melanoma patients dealing with widespread growth of their cancer. Researchers will also work with patients whose tumors, if successfully reduced in size by the virus therapy, could be removed via surgery.
Adding viruses boost immunotherapy results
The study finds patients least likely to respond to immunotherapy treatments alone reacted best to the new combination. Those with the best treatment results had less PDL1 on the surface of their cancer cells. Pembrolizumab typically blocks these chemical receptors. Study authors are now working to understand how V937 changes the molecular makeup of the tissues surrounding tumors.
“Our goal is to determine if the virus turns the tumor microenvironment from ‘friendly’ to one that is ‘unfriendly,’ making the cancer cells more vulnerable to pembrolizumab,” Mehnert concludes.
The researchers are presenting their findings at the annual meeting of the American Association for Cancer Research in April.