Cetuximab, bevacizumab, and irinotecan for patients with primary glioblastoma and progression after radiation therapy and temozolomide: a phase II trial

Abstract

The aim of this clinical trial was to investigate safety and efficacy when combining cetuximab with bevacizumab and irinotecan in patients with recurrent primary glioblastoma multiforme (GBM). Patients were included with recurrent primary GBM and progression within 6 months of ending standard treatment (radiotherapy and temozolomide). Bevacizumab and irinotecan were administered IV every 2 weeks. The first 10 patients received bevacizumab 5 mg/kg, but this was increased to 10 mg/kg after interim safety analysis. Irinotecan dose was based on whether patients were taking enzyme-inducing antiepileptic drugs or not: 340 and 125 mg/m(2), respectively. Cetuximab 400 mg/m(2) as loading dose followed by 250 mg/m(2) weekly was administered IV. Forty-three patients were enrolled in the trial, of which 32 were available for response. Radiographic responses were noted in 34%, of which 2 patients had complete responses and 9 patients had partial responses. The 6-month progression-free survival probability was 30% and median overall survival was 29 weeks (95% CI: 23-37 weeks). One patient had lacunar infarction, 1 patient had multiple pulmonary embolisms, and 3 patients had grade 3 skin toxicity, for which 1 patient needed plastic surgery. One patient was excluded due to suspicion of interstitial lung disease. Three patients had deep-vein thrombosis; all continued on study after adequate treatment. Cetuximab in combination with bevacizumab and irinotecan in recurrent GBM is well tolerated except for skin toxicity, with an encouraging response rate. However, the efficacy data do not seem to be superior compared with results with bevacizumab and irinotecan alone.

Fig. 1.

MRI scan of a 64-year-old man with a PR and a TTP of 342 days. The patient initiated treatment within 4 weeks of the MRI scan originating from August 2007.

Fig. 2.

Kaplan–Meier estimates showing TTP for evaluable patients (n = 32) (A) and OS for the ITT population (n = 43) (B).

Fig. 3.

Examples of EGFR expression by immunohistochemistry scored semiquantitatively on a scale from 0 to 3. (A) 0 = 0%; (B) 1 = 1%–10%; (C) 2 = 11%–50%; (D) 3 = >50% cells stained positive. Arrowheads I showing positive EGFR staining. Arrowhead II showing a vessel, not staining for EGFR.