Triple therapy slows glioblastoma growth and extends survival in preclinical study

The results showed that in both laboratory-grown tumor cells and mice, the triple therapy significantly slowed cancer cell growth, reduced tumor size, and prolonged survival compared to using any single or double treatment. Mice treated with IRT lived an average of 123 days, with some surviving more than 200 days—far longer than the 44 to 103 days observed with other treatment combinations. In addition to directly killing tumor cells, ONC201 and ONC206 lowered the expression of MGMT, a protein that helps tumors resist chemotherapy, making the treatment more effective.

The researchers also found that the triple therapy reshaped the tumor environment. It decreased levels of harmful molecules that promote tumor growth and immune evasion while increasing signals that activate the immune system. This dual action-directly attacking tumors and boosting immune responses—adds to the potential impact of this treatment approach.

“Overall, our preclinical findings support further exploration of the ONC201 and ONC206 IRT regimen as a potential treatment for GBM and diffuse gliomas with H3K27M mutations.”

While these findings are based on preclinical mouse models, they offer strong support for advancing this triple therapy to clinical trials. ONC201 and ONC206 are promising due to their ability to cross the blood-brain barrier and enhance the effects of standard treatment. This combination could lead to more effective therapies for glioblastoma and other hard-to-treat brain tumors.

Reference:

Zhou L, Zhang L, Zhang J, Wu LJ, Zhang S, George A, Hahn M, Safran HP, Chen CC, Seyhan AA, Wong ET, El-Deiry WS. Imipridones ONC201/ONC206 + RT/TMZ triple (IRT) therapy reduces intracranial tumor burden, prolongs survival in orthotopic IDH-WT GBM mouse model, and suppresses MGMT. Oncotarget. 2025 Mar 27;16:230-248. doi: 10.18632/oncotarget.28707.