Glioblastoma Vaccines: What Do Early DNA Trials Show?

How could personalized vaccines help treat glioblastoma?

Recent discussion of cancer vaccines has extended to glioblastoma, an aggressive brain cancer. In an August interview, Wisconsin oncologist Vincent Ma highlighted brain-tumor vaccine research alongside developments in other cancers. This raises a separate clinical question: can a vaccine tailored to a patient's tumor produce a useful immune response against glioblastoma? [WPR interview](https://www.wpr.org/news/wisconsin-doctor-responds-breakthrough-trial-new-cancer-vaccine).

The National Cancer Institute explains that therapeutic vaccines train the immune system to recognize cancer-associated targets called antigens. Some are customized using material from an individual's tumor. Their purpose is to attack an existing cancer or remaining cancer cells after treatment. The ability to direct immunity toward a tumor is the biological rationale; demonstrating that patients live longer requires clinical evidence. [NCI cancer treatment vaccines](https://www.cancer.gov/about-cancer/treatment/types/immunotherapy/cancer-treatment-vaccines).

What did the personalized DNA vaccine trial find?

A phase 1 study published in Nature Cancer in May evaluated GNOS-PV01 after surgery and radiation in patients with MGMT-unmethylated glioblastoma, a molecularly defined subgroup. Nine patients received vaccines encoding 17–40 tumor-specific targets, or neoantigens. Researchers reported no serious adverse events or dose-limiting toxicities. Immune testing showed T-cell activation in evaluated patients except one receiving dexamethasone. [Published trial](https://www.nature.com/articles/s43018-026-01163-w).

The study was open-label and had no randomized comparison group. Consequently, its survival observations cannot establish that vaccination improved outcomes. Nine participants also provide limited ability to detect uncommon harms. The findings support further testing of feasibility, safety and immune activity; they do not establish a new standard treatment. Geneos Therapeutics provided research support, as disclosed in the publication. [Trial methods and disclosures](https://www.nature.com/articles/s43018-026-01163-w).

What comes next for glioblastoma vaccine treatment?

A separate phase 1 study at Washington University pairs a personalized DNA vaccine with retifanlimab, an antibody targeting the immune checkpoint PD-1. The hypothesis is that vaccination directs immune cells toward tumor targets while checkpoint blockade helps sustain their activity. The registry lists 27 enrolled participants and an active study that is no longer recruiting, with no results posted. This remains an experimental combination whose benefits and risks require evaluation. [ClinicalTrials.gov study NCT05743595](https://clinicaltrials.gov/study/NCT05743595).

For newly diagnosed glioblastoma, the National Cancer Institute describes standard treatment as surgery followed by radiation with temozolomide and subsequent temozolomide treatment. Decisions depend on the patient's circumstances. Families interested in vaccine research should discuss trial options early with their neuro-oncology team so that eligibility assessment can be coordinated with planned care. An experimental treatment's immune effects alone cannot determine whether it should replace an established therapy. [NCI brain tumor treatment guidance](https://www.cancer.gov/types/brain/hp/adult-brain-treatment-pdq).