Glioblastoma Treatment Shows Promise with Electric Fields
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A recent study from Keck Medicine of USC suggests a novel combination therapy could significantly improve outcomes for glioblastoma patients, who currently face limited effective treatment options. The approach combines electric fields, immunotherapy, adn chemotherapy.
Electric fields boost Immune Response
The research indicates that Tumor treating Fields (TTFields), which use targeted electric field waves to disrupt tumor growth and stimulate the immune system, may prolong survival for glioblastoma patients when used alongside pembrolizumab (immunotherapy) and temozolomide (chemotherapy).
Did you know? Glioblastoma is one of the most common and aggressive types of brain tumors. It accounts for 14.6% of all primary brain tumors.
TTFields function by interfering with cell division. Low-intensity,alternating electric fields exert force on key structures within tumor cells,hindering their ability to multiply. Patients wear electrodes on the scalp for about 18 hours daily to deliver the treatment at a precise frequency and intensity.
T cells and Tumor Treatment
researchers found that TTFields draw more tumor-fighting T cells into the glioblastoma. Immunotherapy then helps these T cells remain active longer, replaced by even stronger T cells that target the tumor.
“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 David Tran, MD, PhD, chief of neuro-oncology with Keck Medicine, co-director of the USC Brain Tumor Centre and corresponding author of the study. “Our findings suggest that TTFields may be the key to unlocking the value of immunotherapy in treating glioblastoma.”
Unlocking Immunotherapy’s Potential
While immunotherapy has revolutionized treatment for many cancers, it has shown limited success against glioblastoma when used alone. The prognosis for glioblastoma remains poor, even with aggressive treatment combining chemotherapy and other therapies.
Pro Tip: Talk to your doctor about clinical trials. Participating in a clinical trial can provide access to cutting-edge treatments and contribute to advancing medical knowledge.
The study revealed that adding immunotherapy to TTFields and chemotherapy led to a 70% increase in overall survival. patients with larger,unresected tumors experienced an even more robust immune response and lived longer,suggesting that a larger tumor may provide more targets for the therapy.
How Alternating electric Fields Work
Pembrolizumab, the immunotherapy drug used, is an immune checkpoint inhibitor (ICI). ICIs enhance the body’s ability to fight cancer by improving T cells’ ability to identify and attack cancer cells. According to the American Cancer Society, immunotherapy has become an important part of treatment for some types of cancer (American Cancer Society).
Glioblastomas are often shielded from the immune system by the blood-brain barrier, which restricts the entry of cells and substances from the bloodstream. This barrier can block T cells and other therapies.
Tran theorized that initiating an immune reaction directly inside the tumor, known as in situ immunization, using TTFields, could overcome this issue.
“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, who is also a member of the USC norris Extensive Cancer Center.
Study Details and Outcomes
The study analyzed data from the 2-THE-TOP Phase 2 clinical trial, involving 31 newly diagnosed glioblastoma patients who had completed chemoradiation therapy. Twenty-six patients received TTFields combined with chemotherapy and immunotherapy, including seven with inoperable tumors.
Patients received six to 12 monthly chemotherapy treatments alongside TTFields for up to 24 months. Immunotherapy was administered every three weeks, starting with the second chemotherapy dose, for up to 24 months.
Patients using the device with chemotherapy and immunotherapy lived about 10 months longer than those who used the device with chemotherapy alone. Those with large, inoperable tumors lived approximately 13 months longer and showed stronger immune activation compared to patients who underwent surgical removal of their tumors.
“Further studies are needed to determine the optimal role of surgery in this setting, but these findings may offer hope, notably for glioblastoma patients who do not have surgery as an option,”
said tran.
Future Research
Keck medicine is participating in a Phase 3 clinical trial to validate the efficacy of TTFields with immunotherapy and chemotherapy. Tran chairs the steering committee for this trial, and Frances Chow, MD, a neuro-oncologist with USC Norris, is the principal investigator of the Keck Medicine study site.
The Phase 3 trial aims to enroll over 740 patients through April 2029 across 28 sites in the united States, Europe, and Israel.