A Common Vitamin Might Help Fight Deadly Brain Cancer

What if a weapon against one of the deadliest forms of brain cancer was already sitting on pharmacy shelves? Early results from a small Canadian trial suggest that high doses of niacin, a common form of vitamin B, can help the immune system fight glioblastoma when added to standard treatment — keeping the disease from advancing in the large majority of patients at the six-month mark.

The combined early-phase trial, led by oncologist Dr. Gloria Roldan Urgoiti and neuroscientist Dr. Wee Yong at the University of Calgary, enrolled 24 people with newly diagnosed glioblastoma and added controlled-release niacin to the usual course of surgery, chemotherapy and radiotherapy. At six months, 82% of participants had no disease progression — 28 percentage points above the historical benchmark, as reported by Medical Dialogues in its coverage of the interim analysis published in the Journal of Neuro-Oncology.

Why glioblastoma is so hard to beat

Glioblastoma is the most aggressive form of brain cancer, a fast-growing tumor whose cells spread into the surrounding brain tissue, making complete surgical removal nearly impossible. Standard care for this brain cancer has changed little in decades: an operation to remove as much of the tumor as possible, followed by radiation and chemotherapy. Even with all three, the cancer typically comes back.

What makes this brain cancer especially deadly is how it disarms the immune system. The tumor suppresses the body's defenses and reprograms immune cells to protect the cancer instead of attacking it. Immunotherapies that transformed care for melanoma and lung cancer have largely failed against this brain cancer, which keeps the brain's defenses switched off. That immune shutdown is the weakness the Calgary researchers set out to exploit — not by aiming a new drug at the tumor, but by reawakening the immune cells the tumor had silenced.

How a vitamin reactivates the immune attack

The trial's design built in a strict stop rule: the researchers planned to end the study if the share of patients without progression at six months failed to beat previous studies by more than 20 percentage points. The interim readout cleared that bar comfortably, with the six-month outcome running more than a quarter ahead of the historical benchmark.

The mechanism centers on immune reactivation. In earlier laboratory work, niacin restored function in weakened myeloid immune cells — including macrophages and microglia, the brain's resident defenders — improving their ability to target and destroy tumor cells. The vitamin also serves as a precursor for NAD+, a coenzyme central to metabolism and DNA repair, which researchers believe helps exhausted immune cells regain their tumor-fighting capacity.

"Niacin treatment rejuvenates immune cells so they can do what they are supposed to do: attack and kill the cancer cells," Dr. Yong said in the university's release. He describes the fight against this brain cancer as an ongoing battle for the brain, one where the goal is to give the immune system back its weapons rather than attacking the tumor directly.

Why it matters — and the caveats

The road to the clinic has been long. Dr. Yong's lab screened more than a thousand compounds looking for one that could wake up sluggish immune cells, then showed in mouse studies that niacin extended survival. That work grew into the human trial, which will ultimately include 48 participants; with the first half of the group analyzed, the full readout is expected by late 2026 or early 2027. It is the furthest a vitamin-based approach has reached in the fight against this brain cancer.

One of the first participants was Ed Waldner, who was 55 when crushing exhaustion and changes in his walk led to an emergency-department visit and a brain tumor diagnosis. "I have no problem trying to help anybody. I agreed. I want to help myself too," he said of joining the study, according to the university's release as covered by Medical Xpress. His experience is encouraging, but it is also just one patient's story.

For now, the findings remain a preliminary signal, not proof of a treatment. The study was small and single-arm, comparing results against historical data rather than a randomized control group, and larger trials will be needed to confirm whether the early signal translates into longer survival. High-dose niacin is also not harmless — megadoses can cause liver damage and gastrointestinal distress — so patients should not start supplementing on their own and should ask their oncologist about enrolling in clinical trials instead.

Still, the result matters because glioblastoma has a median survival of roughly 12 to 18 months and has resisted decades of new drugs. A cheap, repurposed compound that cooperates with standard treatment — if confirmed in the full analysis — could open a new front in the treatment of this brain cancer, one that recruits the immune system rather than trying to work around it.