ATNT-27ASSESSING THE SAFETY OF COMBINATION THERAPY WITH BEVACIZUMAB AND OPTUNETM FOR HIGH GRADE GLIOMAS.

BACKGROUND: The prognosis for patients with high grade gliomas remains dismal. In addition to cytotoxic therapy, the FDA has approved bevacizumab and OptuneTM (Tumor Treating Fields) for recurrent glioblastoma. Given the prognosis and multiple treatment options, many clinicians have elected to offer combined therapy. We examined our patient population at two institutions where combination therapy has been used. METHODS: We retrospectively reviewed clinical courses of all patients receiving OptuneTM who have been concurrently managed with bevacizumab or experienced prior therapy with bevacizumab. Toxicity was described for those patients. Patients who received OptuneTM for at least 4 weeks with concurrent bevacizumab were analyzed for overall survival from time of initiation of concurrent therapy. RESULTS: We identified 37 patients, 26 males and 11 females. Of those, 33 patients received concurrent therapy, and all of those patients had prior bevacizumab exposure. OptuneTM was started as single therapy in 4 patients after bevacizumab exposure and failure. 6 patients experienced contact dermatitis which did not delay therapy. 1 patient had a small skin erosion which did not delay therapy. 2 patients had small skin erosions which delayed OptuneTM therapy. 1 patient had folliculitis and skin erosions and ulcers which necessitated cessation of therapy. 1 patient had a grade 2 intracranial bleed with no clinical sequelae aside from the need to hold bevacizumab. 29 patients received this therapy for at least 4 weeks. Median duration of concurrent therapy was 4 months. Median OS from initiation of concurrent therapy was 5.3 months. CONCLUSIONS: In our dataset, there was no toxicity appreciated aside from mild skin toxicity in the majority of patients. Combining bevacizumab and OptuneTM does not appear to significantly increase risk of bleeding or stroke. The incidence and severity of skin reactions were comparable to those described previously. Additional trials to investigate this combination are ongoing.