ATIM-20. CLINICAL OUTCOMES WITH IPILIMUMAB IN COMBINATION WITH BEVACIZUMAB IN PATIENTS WITH RECENTLY DIAGNOSED GLIOBLASTOMA - A RETROSPECTIVE COHORT REVIEW

Abstract

BACKGROUND

Median survival for patients with glioblastoma remains under a year. Whilst there is accumulating interest in the role of checkpoint inhibitors in newly diagnosed glioblastoma, the results of clinical trials are awaited to establish clinical efficacy. We have previously presented clinical outcomes in patients with relapsed glioblastoma treated with the anti-CTLA-4 monoclonal antibody ipilimumab in combination with the anti-VEGF monoclonal antibody bevacizumab.

METHODS

We retrospectively identified patients with newly diagnosed WHO grade IV glioma who received treatment with ipilimumab and bevacizumab at our centre between March 2015 and March 2017. Baseline demographics, tumour characteristics, concurrent therapy, radiological responses, and survival data were analysed.

RESULTS

Nineteen patients were identified, 18 with glioblastoma and one with a glioneuronal tumour (Grade IV). Median age was 52 years (range 22–85) and 79% were male. 5% (1/19) had an IDH mutation, and 38% (6/16) had MGMT promotor methylation. Ipilimumab (3mg/kg, 3 weekly, 4 cycles) and bevacizumab (10mg/kg 2 weekly), given with concurrent G-CSF or GM-CSF were commenced after radiotherapy (except in one patient who did not receive radiotherapy). 58% of patients had prior surgical debulking (42% biopsy only), 79% had prior radical radiotherapy with concomitant temozolomide, 16% had short course radiotherapy, and 5% did not receive radiotherapy. 84% of patients received adjuvant temozolomide, and 89% received concurrent valganciclovir. In those with visible disease on pre-treatment MRI, 62% (8/13) had a radiological response. At time of analysis, 63% of patients remained alive, and 58% were alive and progression free. Median follow up was 15 months. Median survival in patients who had had debulking surgery was 23 months, and median survival in those who had a biopsy only was 16 months.

CONCLUSION

This combination requires prospective evaluation in clinical trials to formally determine efficacy. Data on this cohort continues to be collected and will be updated.