Global tumor board maps investigational options for glioblastoma with MDM2 and EGFR amplifications

A 55-year-old man who experienced dizziness and a generalized seizure in February 2023, followed by impaired speech, became the subject of an unusually detailed exploration of precision oncology in brain cancer. Brain imaging revealed a small mass in his left temporal lobe, and after another seizure in June 2023, repeat imaging showed that the lesion had grown substantially, with a hyperintense mass in the left medial temporal lobe measuring 2.49 by 1.71 centimeters and infiltrating the hippocampus, amygdala and anterior temporal lobe. Surgeons performed an anterior temporal lobectomy and amygdalohippocampectomy, and histopathological examination confirmed the diagnosis of glioblastoma, an aggressive primary brain tumor in adults characterized by rapid growth, extensive infiltration into surrounding tissue and frequent recurrence. His case, published as a case report in Volume 17 of Oncotarget on October 16, 2026, was examined by the Worldwide Innovative Network (WIN) Consortium’s International Molecular Tumor Board, whose specialists weighed a series of investigational strategies against the molecular profile of his tumor.

The report was led by first and corresponding author Dr. Wafik S. El-Deiry, Editor-in-Chief of Oncotarget, affiliated with the WIN Consortium and the Legorreta Cancer Center at Brown University, with equal-contributing author Razelle Kurzrock of the WIN Consortium and the Medical College of Wisconsin. “This case underscores the immense complexity of treating GBM,” the authors wrote in the report. The statement captures a central dilemma in neuro-oncology: standard treatment for glioblastoma generally combines maximal safe surgical resection, radiotherapy and temozolomide chemotherapy, yet median survival remains approximately 15 months. That figure, the report notes, underscores the need for additional therapeutic approaches, particularly for tumors whose molecular makeup may blunt the benefit of conventional therapy.

One major obstacle to improving those outcomes is molecular heterogeneity, the phenomenon by which tumors contain genetic alterations that influence growth, treatment response and resistance. Next-generation sequencing can help identify these abnormalities and reveal potential targets for individualized treatment. In this patient, comprehensive molecular profiling revealed an IDH-wildtype tumor with an unmethylated MGMT promoter, a feature generally associated with reduced benefit from temozolomide compared with MGMT-methylated tumors. Additional testing identified amplifications of the EGFR and MDM2 genes, a CDKN2A frameshift alteration and other genomic abnormalities, a constellation of findings that shaped every subsequent treatment discussion.

Each of these alterations carries mechanistic significance. MDM2 regulates p53, a tumor-suppressor protein involved in controlling cell division and eliminating damaged cells, and amplification of MDM2 can weaken p53-mediated tumor suppression, potentially promoting cancer-cell survival and treatment resistance. EGFR amplification can activate signaling pathways that support tumor growth and invasion, while CDKN2A alterations disrupt cell-cycle regulation through the p16–CDK4/6–RB pathway. Together, the report explains, these findings provided a rationale for investigating therapies aimed at multiple molecular vulnerabilities simultaneously rather than relying on a single target.

The diagnostic workup was not without ambiguity. Comprehensive testing consistently identified the MDM2 and EGFR amplifications, but it produced conflicting results regarding microsatellite instability. One analysis classified the tumor as microsatellite stable, while another indicated instability. Because this discrepancy was not resolved through confirmatory testing, its potential implications for immunotherapy remained uncertain. The report uses this unresolved result to emphasize a broader point: molecular findings must be interpreted cautiously, and confirmatory testing matters before clinical decisions rest on a single assay.

Following surgery, the patient received radiotherapy and temozolomide, the standard post-operative regimen. In September 2023, he enrolled in a phase II clinical trial involving paxalisib, an investigational PI3K/mTOR inhibitor, combined with a ketogenic diet and metformin. At the time of the molecular tumor board discussion, the patient was in remission while receiving this experimental approach. The report is explicit, however, that it does not establish which component of his overall treatment contributed to disease control. The patient was also considering personalized neoantigen vaccine therapy, an investigational approach designed to stimulate immune responses against tumor-specific mutated peptides, but the report does not indicate that the vaccine had been administered.

To identify options in the event of recurrence, the WIN Consortium International Molecular Tumor Board brought together precision oncology specialists from 18 organizations across 13 countries. The experts evaluated the patient’s clinical history, genomic findings and tumor microenvironment to explore potential targeted and immune-based therapies. One strategy involved EGFR inhibitors, including investigational agents designed to reach tumors within the central nervous system. The board discussed ERAS-801 and possible combinations involving osimertinib or lapatinib with the EGFR-targeting antibody cetuximab. Their effectiveness in this patient’s tumor was not established, and access would depend on clinical trial availability and eligibility, a constraint that applies to most targeted agents in glioblastoma.

The experts also considered MDM2 inhibitors, including navtemadlin, idasanutlin and milademetan, as potential approaches to restoring p53-mediated tumor suppression in a tumor whose MDM2 amplification had undermined it. Because these agents are not approved for glioblastoma, their use would remain investigational and require appropriate clinical trial or regulated access. Another proposed strategy involved combining EGFR-targeted therapy with CDK4/6 inhibition to address both the EGFR amplification and the CDKN2A loss. Abemaciclib, a CDK4/6 inhibitor with demonstrated central nervous system penetration, was discussed as a possible component. The report stresses that these combinations remain proposed treatment options rather than therapies validated in the reported patient.

Immunotherapy presented additional challenges. The tumor board discussed evidence linking MDM2 and EGFR alterations to resistance or accelerated tumor progression during immune checkpoint blockade in selected cancers, while noting that these associations do not establish that similar outcomes would occur in this patient. The tumor microenvironment itself showed substantial CD4 and CD8 T-cell infiltration, alongside regulatory T cells and moderate PD-L1 expression. These findings suggested immune activity but also potential immune suppression, raising questions about whether combining targeted treatments with immunotherapy might improve responses. Such approaches, the report notes, require further investigation. The board also discussed teserpaturev (Delytact), a genetically modified herpes simplex virus designed to destroy tumor cells and stimulate antitumor immune responses. Although available in Japan under specific regulatory conditions, its potential benefit for this patient remained uncertain.

The report further highlights the importance of cautious interpretation of molecular findings. CDKN2A alterations raised the possibility of concurrent MTAP loss, which could offer opportunities for additional targeted approaches, but MTAP status was not confirmed, and further testing would be necessary before considering therapies directed at that vulnerability. As a single-patient case report, the findings cannot establish the effectiveness of the proposed treatments or determine whether specific genetic alterations predict clinical responses. The patient was in remission at the time of discussion, and the additional targeted combinations were considered as future options rather than administered therapies. The tumor board prioritized clinical trial enrollment if the disease recurred, particularly trials evaluating EGFR-directed therapies, MDM2 inhibition, immune-modulating strategies or biomarker-matched combinations, all of which remain investigational and require prospective evaluation to establish their safety and effectiveness. “This case emphasizes the importance of personalized treatment strategies for GBM and the need for ongoing clinical research to explore novel therapeutic options,” the authors concluded. Overall, the report illustrates how international molecular tumor boards can integrate genomic profiling, clinical information and emerging therapeutic research to identify personalized treatment opportunities, and it highlights the potential value of multidisciplinary collaboration in managing complex cancers such as glioblastoma, even as the proposed strategies await validation.

Subject of Research: A single-patient case report on molecular tumor board evaluation of personalized treatment options for glioblastoma with MDM2 and EGFR amplifications

Article Title: International tumor board explores personalized treatment options for glioblastoma with MDM2 and EGFR amplifications

Article References: International tumor board explores personalized treatment options for glioblastoma with MDM2 and EGFR amplifications. Original publication (Bibliographic details unavailable.)

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Keywords: glioblastoma, precision oncology, molecular tumor board, MDM2, EGFR, CDKN2A, paxalisib, next-generation sequencing, WIN Consortium, case report, immunotherapy, MGMT promoter methylation