Combining two therapies could make the tumor regress and improve the chances of survival in some patients.
- Scientists have tested the effectiveness of a therapy combining the injection of an oncolytic virus and intravenous immunotherapy in a clinical trial.
- In more than half of patients with recurrent glioblastoma, brain tumors have shrunk and some have even disappeared.
- As for their median survival after treatment, it was estimated at 12.5 months.
It is the most common and deadliest tumor in adults. Glioblastoma develops from glial cells in the brain and is characterized by aggressive behavior and resistance to treatment. “Despite the various therapies available, patients invariably experience a recurrence of their disease on average seven months after diagnosis,” American researchers said. This recurrence is usually associated with a rapid deterioration in the patient’s health. “Unfortunately, therapeutic options in the event of recurrence are rare. Those that exist have very limited efficacy, with median survival being only around 6 to 8 months after tumor progression”, they added.
Combining oncolytic virus injection and intravenous immunotherapy
That’s why scientists wanted to test the effectiveness of a new approach to treating glioblastoma. The latter combines the injection of an oncolytic virus directly into the tumor and intravenous immunotherapy. The oncolytic virus used specifically targets cancer cells, while immunotherapy boosts the body’s immune response against the tumor. To determine the maximum tolerated dose of this combination therapy, they performed a phase I/II clinical trial. As part of the study, they recruited 49 people with recurrent glioblastoma.
Glioblastoma: a median survival of 12.5 months and brain tumor shrinkage
According to the results, published in the journal NatureMedicinethis combination therapy would have made it possible to regress the tumor in some patients. “More than half of our patients achieved clinical benefit – stable disease or better – and we saw remarkable responses with tumors that shrank, and some even completely disappeared,” said Dr. Farshad Nassiri, author of the work and researcher at the University of Toronto (Canada), in a statement.
Another finding: the treatment allowed a median survival of 12.5 months, which is considerably longer than the six to eight months generally observed with existing therapies. “Three patients are still alive 45, 48 and 60 months after the start of the clinical trial”, said Dr. Farshad Nassiri. Furthermore, the combination therapy did not cause major adverse effects. “We believe that the key to our success has been to deliver the virus directly into the tumor before using systemic immunotherapy. Our results clearly show that this approach can be safe and effective,” continued the researcher.
A new genetic signature associated with treatment response
After discovering these promising results, the team also performed genetic analyzes on the patients’ tumor samples. They identified immune characteristics that could potentially help doctors determine responses to treatment and understand resistance mechanisms in glioblastoma. This discovery could help predict which people are most likely to benefit from this new therapeutic approach.
