Sequential immunotherapy and bevacizumab treatments in glioblastoma multiforme: A case series and review of the literature

Glioblastoma multiforme (GBM) is a tumor with a high refractory rate to immunotherapy and a low tumor mutational burden phenotype, leading to limited immunogenic neoantigens. The present study aimed to investigate the sequential use of immunotherapy and bevacizumab in patients with GBM, exploring the clinical outcomes and potential complications. Patients received various combinations of immunotherapy and bevacizumab after standard treatment, including surgery, radiotherapy and temozolomide. Clinical courses, radiological findings and treatment outcomes were monitored and documented during each clinical visit through routine physical examinations, imaging studies and review of medical records. The efficacy and side effects of this sequential drug approach remained unclear. The common features of these patients were a marked decline in cognitive function and clinical deterioration, assessed clinically in the absence of obvious tumor progression. Radiological evaluation was also performed, particularly for possible cerebrovascular events. In these cases, the potential for sequential treatment to suppress tumors while inducing cerebrovascular events was also investigated, and patients were not lost to overt tumor progression. Notably, further research is required to clarify the mechanisms of action and complications associated with the sequential use of immunotherapy and bevacizumab in the treatment of GBM.