High-dose vitamin B3 kept 82% of glioblastoma patients progression-free at six months in a small trial

At the six-month mark, 82% of the first 24 people in a University of Calgary glioblastoma trial had not seen their cancer progress. All 24 had newly diagnosed disease, and all took high-dose, controlled-release vitamin B3 (niacin) alongside standard chemotherapy and radiotherapy.

The result is an interim reading from a single-arm phase 1-2 study that combined a safety and dose-finding stage with a first look at benefit, and the team plans to enroll 48 patients before a final analysis expected around the end of 2026 or early 2027.

Niacin added to the standard regimen

Gloria Roldan Urgoiti, an oncologist and clinical associate professor at Calgary’s Cumming School of Medicine, and V. Wee Yong, a neuroscientist at the school’s Hotchkiss Brain Institute, led the trial. The paper, a safety and interim phase 2 analysis of niacin in patients with newly diagnosed glioblastoma, was published online Nov. 28, 2025 in the Journal of Neuro-Oncology, volume 176, issue 1, page 101, with Paula de Robles, Gregory Cairncross and other Calgary colleagues among the authors. The Canadian Institutes of Health Research and the Alberta Cancer Foundation funded it.

The treatment sits on top of the usual sequence rather than replacing any part of it. After surgery, participants received the niacin along with chemotherapy and radiation, and the trial’s purpose in phase 1 was to find the highest dose that could be given safely. The University of Calgary release calls the doses high but does not state the milligram figure, so none is given here.

The standard options for glioblastoma, a grade IV tumor that grows quickly and usually cannot be fully removed, include surgery followed by radiation and chemotherapy together and then chemotherapy alone, according to the National Cancer Institute’s adult brain tumor treatment summary.

The 82% interim result against historical studies

The primary measure was progression-free survival, the time patients live without the cancer getting worse. In the interim analysis of 24 patients, 82% were free of progression at six months. The university describes that as a 28% increase over previous studies, wording that does not say whether the gain is absolute or relative, and the release does not give the exact number of patients who stayed progression-free. The trial had a built-in stopping rule, set in advance by the investigators: it would end if six-month progression-free survival did not improve by at least 20% compared with older studies. It cleared that bar in the interim data, so enrollment continues toward 48.

Because the trial has no control group, the comparison is against historical results from earlier glioblastoma studies, not against patients randomized alongside the niacin group. That design can show whether a drug is worth testing further; it cannot show that the drug caused the difference.

The mouse work behind the trial

The idea began in Yong’s laboratory, where niacin prolonged survival in mice. The reasoning, described in a 2021 University of Calgary account of the trial’s launch, is that glioblastoma suppresses the immune system that is trying to attack it; a 2014 Nature Neuroscience paper had found that the brain’s immune cells, the microglia, do not function properly around the tumor. Mouse work in Science Translational Medicine in 2020 showed niacin combined with temozolomide extended survival. Enrollment began in April 2021, at the Tom Baker Cancer Centre in Calgary, for adults up to age 75.

Yong described the intended effect this way: “Niacin treatment rejuvenates immune cells so they can do what they are supposed to do, attack and kill the cancer cells.” Roldan Urgoiti, for her part, put the weight on caution: “Anything that may help should be explored, but it requires strict protocols and safety monitoring.” The Canadian Cancer Trials network’s write-up of the study repeats the stopping rule and the interim figures from the Calgary team.

Niacin toxicity and the monitoring requirement

The researchers warn that high doses of vitamins such as niacin can be toxic and should be given only under close monitoring by medical professionals. The release reports no adverse-event results, so how well patients tolerated the doses is not stated in the material available. Roldan Urgoiti has said glioblastoma is the most aggressive brain cancer in adults, and that patient survival has changed little in about 20 years, which is the gap the niacin trial was set up to probe. Even with surgery, radiation and oral chemotherapy, the tumor usually returns within about a year, according to the 2021 Calgary account, and the 24-patient interim figure has to be read against that backdrop.

A republished version of the release added a participant’s view: Ed Waldner, a patient in the research, said it helps him mentally to be part of an effort in which the team is trying something new. The final analysis of all 48 patients will show whether the 82% figure holds when the trial reaches its full size, and the release names the end of 2026 or early 2027 as the earliest it will report.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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