These rare, highly resistant cells are why patients relapse
Among the most merciless of human diseases, glioblastoma has long resisted medicine's best efforts, offering patients little more than eighteen months of survival even after surgery and chemotherapy. Now, researchers at the University of Ottawa have found that edaravone — a drug already approved for ALS and stroke — may strike at the very stem cells that allow this brain cancer to endure and return. Because the drug has already cleared the long gauntlet of human safety testing, the distance between this laboratory discovery and a clinical trial is shorter than it would otherwise be. In the landscape of a disease where hope has been scarce, that compression of time carries its own quiet weight.
- Glioblastoma's median survival of eighteen months has barely shifted for decades, driven by treatment-resistant stem cells that cause the tumor to return even after surgery and chemotherapy.
- Dr. Arezu Jahani-Asl's team at the University of Ottawa identified that edaravone disrupts the self-renewal and proliferation of these brain tumor stem cells — the very mechanism behind glioblastoma's lethality.
- Gene expression analysis in patient-derived cells revealed that edaravone significantly disturbs the pathways governing stemness and DNA repair, and animal models confirmed it sensitizes tumors to radiation therapy.
- Because edaravone is already FDA-approved and proven safe in humans for ALS and stroke, researchers can bypass years of early-stage safety trials and move more rapidly toward glioblastoma clinical trials.
- The team is now working to establish the optimal dosage range — a safe therapeutic window — for combining edaravone with radiation and chemotherapy before advancing to human trials.
Glioblastoma is the most common and most lethal primary brain tumor in adults. Even with surgery and chemotherapy, patients survive a median of eighteen months. The cancer resists treatment not by accident but by design: rare populations of brain tumor stem cells endure standard therapies and seed the tumor's return. They are the reason patients relapse, and the reason survival times have plateaued for so long.
A research team at the University of Ottawa, led by Dr. Arezu Jahani-Asl, has found that edaravone — already approved by the FDA under the brand name Radicava to slow ALS progression, and also used in stroke treatment — can suppress these stem cells. Published in Stem Cell Reports, the findings show that edaravone inhibits the self-renewal and proliferation of brain tumor stem cells, and does so most powerfully when paired with the ionizing radiation already used in standard glioblastoma care.
The team began with gene expression analysis comparing patient-derived brain tumor stem cells exposed to edaravone against untreated cells. They found significant disruption in gene networks governing stemness and DNA repair — an observation that grew into a broader investigation, ultimately producing animal model evidence that edaravone sensitizes glioblastoma tumors to radiation.
What gives this discovery particular momentum is what it skips. Edaravone is not a new compound requiring years of preclinical safety work. It has already been proven safe in humans. That means researchers can potentially move far more quickly toward testing it in actual glioblastoma patients. The team's next step is identifying the optimal dose for combining edaravone with radiation and chemotherapy — establishing the therapeutic window where the drug is effective without causing harm. Once found, clinical trials can follow.
The aim is not to replace existing treatments but to make them work better — to give radiation and chemotherapy a fighting chance against cells that have learned to survive both. For patients whose prognosis has remained grim for decades, that possibility represents something glioblastoma treatment has rarely offered: a credible reason for hope.
Glioblastoma kills with a particular cruelty. It is the most common primary brain tumor in adults, and also the most lethal. Even when patients undergo surgery to remove it and receive chemotherapy afterward, the median survival stretches only to eighteen months. The cancer is aggressive, resistant to treatment, and for practical purposes, incurable.
A team of researchers at the University of Ottawa, led by Dr. Arezu Jahani-Asl, has found something that might change that calculus. They discovered that edaravone—a drug already approved by the FDA and already in use for a different disease entirely—can suppress the stem cells at the heart of glioblastoma's deadliness. The findings, published in Stem Cell Reports, suggest a path forward that bypasses years of drug development and safety testing.
The reason this matters is specific and urgent. Brain tumor stem cells are what make glioblastoma so hard to kill. These are rare, highly resistant populations of cancer cells that survive standard treatment and cause the tumor to come roaring back. They are the reason patients relapse. They are the reason survival times plateau. Targeting them directly could break that cycle. Glioblastoma affects roughly four per 100,000 people in Canada, and the disease carries the same grim prognosis worldwide.
Edaravone, sold under the brand name Radicava, was approved by the U.S. Food and Drug Administration in 2017 to slow the progression of ALS. Health Canada approved an oral version in 2022. The drug is also used to treat stroke. What Jahani-Asl's team found is that it does something else: it inhibits the self-renewal and proliferation of brain tumor stem cells. More importantly, it does this work most effectively when combined with ionizing radiation—the same radiation therapy already used in standard glioblastoma treatment.
The research began with gene expression analysis in patient-derived brain tumor stem cells, comparing cells exposed to edaravone with those that were not. The team found significantly disrupted gene panels related to stemness and DNA repair mechanisms. That observation became the spark for a larger investigation, which eventually produced evidence in animal models that edaravone sensitizes glioblastoma tumors to radiation therapy.
What makes this discovery particularly promising is the shortcut it offers. Edaravone is not a new compound. It has already been proven safe in humans. It has already been approved for clinical use. This means that instead of spending years in preclinical development and early-stage safety trials, researchers can potentially move directly toward testing whether the drug works in actual glioblastoma patients. The path from laboratory finding to clinical application is compressed.
Jahani-Asl and her team are now focused on the next phase: determining the optimal dose of edaravone to use in combination with ionizing radiation and chemotherapy. They need to establish what they call a safe therapeutic window—the dosage range where the drug is effective without causing unacceptable harm. Once they identify that window, they will have the knowledge needed to move the treatment into clinical trials.
Any new drug for glioblastoma will be used alongside existing standard treatments, not as a replacement for them. The goal is to make those existing treatments work better, to give the immune system and the radiation a fighting chance against cells that have learned to resist everything thrown at them. For patients facing an eighteen-month median survival, the possibility of extending that timeline, or of achieving remission, represents something that has been absent from glioblastoma treatment for a long time: genuine hope.
Notable Quotes
Edaravone specifically targets cancer stem cells and is particularly effective in combination with ionizing radiation, and is expected to decrease the chance of resistance to therapy and recurrence in glioblastoma patients.— Dr. Arezu Jahani-Asl, University of Ottawa
Our goal is now to try to optimize dosage for a safe therapeutic window. Once we establish a dose that is safe for use in combination therapy, we will be well equipped with the knowledge to move this forward to clinic.— Dr. Arezu Jahani-Asl
The Hearth Conversation Another angle on the story
Why does it matter that this drug is already approved for ALS? Why not just develop something new?
Because glioblastoma patients don't have years to wait. If you're starting from scratch with a new compound, you're looking at a decade or more of safety testing before you can even ask if it works in humans. Edaravone has already been through that. We know it's safe. That collapses the timeline dramatically.
So the stem cells are the real problem—not the bulk of the tumor itself?
Exactly. You can shrink the main tumor with surgery and chemotherapy, but these stem cells hide and survive. They're like the seeds of the cancer. Kill the seeds, and you stop the regrowth. That's what makes this finding so significant.
How confident are the researchers that this will actually work in patients?
They're moving carefully. They've shown it works in animal models and in lab-grown patient cells. The next step is figuring out the right dose. They're not claiming victory yet—they're being methodical about moving toward clinical trials.
What happens if the dosage is too high?
That's the whole question they're trying to answer now. Too much of any drug causes harm. They need to find the sweet spot where edaravone kills the cancer stem cells without damaging healthy brain tissue. That's the work ahead.
If this works, how soon could glioblastoma patients actually receive it?
That depends on how quickly the dosage optimization goes and how the regulatory process moves. But because the drug is already approved, it could potentially be available much faster than a completely new treatment would be. We're talking years, not decades.