Findings from a phase 2 study show feasibility of border zone stereotactic radiosurgery with bevacizumab for the treatment of patients with recurrent or progressive glioblastoma following conventional upfront management. These findings were published alongside the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting. 

Eligible patients had histologically confirmed glioblastoma with recurrent disease; had received prior first-line treatment with surgery/biopsy, fractionated radiotherapy, and chemotherapy; surpassed ≥2 months since completion of radiotherapy; and were eligible for stereotactic radiotherapy. Efficacy of border zone stereotactic radiosurgery with bevacizumab was assessed by overall survival (OS).

Bevacizumab was administered at 10mg/kg 1 day before, on day 14, and then every 14 days until disease progression. Patients underwent standard brain MRI/MRS 1 to 14 days before border zone stereotactic radiosurgery. MRS with measurement of choline-to-N-acetyl aspartate index (CNI) area ≥3 was targeted for stereotactic radiosurgery using standard MRI targeting.

At total of 16 patients were enrolled between 2015 and 2017. Of these, 3 patients experienced grade 2 unacceptable toxicity. Median OS was 11.73 months. The 6-month PFS was 31.2% (P = .00294) and OS was 81.2% (P = .058). 

Researchers noted that there was no survival difference observed in this study compared with historical controls from the University of Pittsburgh.

There were 13 patients evaluable for best response: 1 complete response (P = .077), 4 partial responses (P = .308), 7 stable disease (P = .538), and 1 progressed disease (P = .077). Overall, 11 out of 16 patients had MRS scans with an estimated probability that MRS changes a treatment plan of 0.

In conclusion, these study results demonstrate the feasibility of border zone stereotactic radiosurgery with bevacizumab for patients with recurrent or progressive glioblastoma.

Source:

Mantica M, Drappatz J, Lunsford D, Lieberman FS, Niranjann A. Phase II study of border zone stereotactic radiosurgery with bevacizumab in patients with recurrent or progressive glioblastoma multiforme. Presented at 2023 ASCO Annual Meeting; June 2-6, 2023; Chicago, IL. Abstract e14020