Electric Fields, Immunotherapy Combo‌ Shows Promise in Glioblastoma​ Treatment

Updated June 09, 2025

A new study from Keck Medicine of USC suggests a potential breakthrough ⁤in treating glioblastoma, an aggressive brain tumor. The research indicates that Tumor⁤ Treating Fields (TTFields) therapy, in conjunction with immunotherapy and chemotherapy, may considerably extend survival for patients. ​The National Brain‍ Tumor Society reports​ that average ‌survival post-diagnosis is typically only eight months.

TTFields use⁢ targeted electric fields to disrupt ⁤tumor growth and stimulate​ the body’s immune response. These low-intensity, alternating electric fields interfere with cell ‍division, giving patients a better chance to ‍fight the cancer. The therapy involves wearing mesh electrodes on the scalp for about 18 hours daily, delivering precisely calibrated fields to the tumor.

The study revealed that TTFields draw tumor-fighting T cells to the glioblastoma. When followed by immunotherapy, these T cells remain active longer and are replaced ⁤by more effective cells.

Dr. David Tran, chief⁣ of neuro-oncology with Keck Medicine and ⁣co-director of the USC Brain Tumor Center, ‌said that TTFields prime the body to attack the cancer, enabling immunotherapy to ​have a meaningful effect. He added that their findings suggest TTFields may unlock the value of immunotherapy in treating glioblastoma.

While TTFields are frequently enough used with chemotherapy, glioblastoma prognosis ​remains poor. Immunotherapy alone has also proven ineffective for this cancer type.

However, the study found that ⁣adding immunotherapy to ‌TTFields and chemotherapy was⁢ associated with a 70% increase in overall survival. Patients with larger,unresected tumors showed an even stronger ⁢immune response and lived longer,suggesting that a larger tumor may provide ⁢more targets for the⁤ therapy.

⁤ ‍”By using TTFields with immunotherapy, we prime the body to mount‌ an‌ attack on the cancer, which enables the immunotherapy to have a meaningful effect in ways that it could not ‌before,” said Dr. David Tran, MD, PhD, chief of neuro-oncology with Keck Medicine.
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Pembrolizumab, the immunotherapy used, enhances the body’s ability to fight cancer by improving⁣ T⁢ cell function. Glioblastomas, however, are ⁢often shielded from the immune system by ‍the blood-brain barrier, which limits the entry of ​T ‌cells and other therapies.

Tran theorized that initiating an immune reaction directly within the tumor, using TTFields, could overcome this issue. The study demonstrates that combining TTFields with immunotherapy triggers a ‍potent immune ‍response that can be amplified by immune checkpoint inhibitors.

⁢”Think of it like a team sport — immunotherapy sends players in to attack the tumor (the offense), while TTFields ​weaken ⁣the tumor’s ability to fight back (the defense). And just like in team sports, the best defense is a good offense,” said Tran.

The study analyzed data from a ‍Phase 2 clinical trial ⁢involving 31 newly diagnosed glioblastoma patients. Twenty-six received TTFields with chemotherapy and immunotherapy. Seven of these 26 had inoperable tumors.

Patients received six to 12 monthly chemotherapy treatments alongside TTFields for up to 24‌ months. Immunotherapy was given‍ every three weeks, starting with⁢ the second chemotherapy dose, for up to 24 months.

Patients using TTFields with chemotherapy and immunotherapy lived ⁤about 10 ​months longer than those using TTFields with chemotherapy alone. Those with large, inoperable tumors lived approximately 13‍ months longer and showed stronger immune activation.

Tran said further studies ​are needed to determine‍ the optimal role ⁤of surgery,but these findings offer hope,especially ‍for glioblastoma patients who cannot undergo surgery.

What’s‌ next

Keck Medicine is participating in a Phase 3 clinical ‌trial to validate the ⁢efficacy of TTFields with immunotherapy and chemotherapy. The​ trial aims⁢ to​ enroll over‍ 740 patients to ​assess how surgically removing tumors influences ⁣immune response.