Recurrent high-grade glioma treated with bevacizumab: prognostic value of MGMT methylation, EGFR status and pretreatment MRI in determining response and survival

Recurrent GBM and bevacizumab

J Neurooncol (2013) 115:267–276

Although bevacizumab represented an important advance in treatment of recurrent high-grade gliomas (HGG), responses occur in fewer than half of patients. There are no validated biomarkers for anti-angiogenic therapy that are available for routine clinical use.

We assessed the prognostic values of imaging and molecular markers in this patient population. MRI scans from 191 patients with recurrent HGG obtained prior to initiating bevacizumab were reviewed for areas of enhancement, necrosis, T2/FLAIR abnormality, and ADC values. Serial MRI scans following the initiation of bevacizumab were evaluated for response and progression. Non-radiographic markers including EGFR and MGMT status were also assessed with respect to response and patient survival.

65 of 191 patients (34 %) showed complete or partial response at the time of their best response MRI and demonstrated longer progression free survival (PFS) and overall survival (OS) compared to the group without response (PFS: 6.9 vs 3.5 months, OS: 10.9 vs 6.1 months). Minimum ADC values within enhancing and non-enhancing regions were lower in responders compared to those of nonresponders (1,099 vs 984 x 10-6 mm2/s, p = 0.006). Smaller enhancing area was associated with longer OS (HR = 1.99, p = 0.017). The ratio of T2/FLAIR to enhancing area was prognostic of OS for only the Grade III HGG subgroup (HR = 0.14, p = 0.004).

Area of enhancing tumor at baseline can stratify survival in patients with recurrent HGG treated with bevacizumab. The extent of edema relative to enhancing area may have a prognostic role specific to Grade III HGG.

Targeted therapy with bevacizumab and erlotinib tailored to the molecular profile of patients with recurrent glioblastoma

Targeted therapy with bevacizumab and erlotinib tailored to the molecular profile of patients with recurrent glioblastoma

Acta Neurochir (2013) 155:33–40

Advances in comprehension of molecular biology of glioblastoma (GBM) have led to the development of targeted therapies. The aim of the present study was to evaluate the efficacy and safety of a targeted therapeutic approach in which administration of bevacizumab and erlotinib was tailored on the molecular profile of recurrent GBM.

Methods We prospectively enrolled ten adult patients suffering from recurrent GBM who had undergone surgical resection and standard chemo-radiotherapy. Tumor tissue was assessed for the expression of EGFRvIII and MGMT promoter methylation by RT-PCR, and for PTEN and VEGF expression by immunohistochemistry. Normal PTEN status was required for inclusion. Patients with VEGF overexpressing tumors (10/10) were treated with bevacizumab (10 mg/kg iv every 2 weeks in 6-weekcycles); patients whose tumor expressed EGFRvIII (4/ 10) added erlotinib (150 mg/day orally; 300 mg/day if on enzyme-inducing antiepileptic drugs). Therapy was continued until disease progression or unacceptable toxicity. Primary endpoints of the study were response rate (RR), 6-month progression-free survival (PFS-6), and safety profile.

Results The RR and PFS-6 were 100 % (4/4) and 50 % (3/6) in patients treated with bevacizumab+erlotinib (n=4) and bevacizumab (n=6), respectively. In the whole cohort (n= 10), RR and PFS-6 were both 70 % (7/10); median PFS and overall survival (OS) were 8.0 (3.0–31.0) and 9.5 (5.0–31.0) months, respectively. No grade 3/4 adverse events were observed; three patients treated with bevacizumab+erlotinib displayed grade 1/2 rash not requiring dose reduction; one patient treated with bevacizumab developed intratumoral hemorrhage requiring treatment discontinuation.

Conclusion To our knowledge, this is the first study on recurrent GBM in which administration of bevacizumab and erlotinib was tailored on the molecular profile of the patient’s tumor. Although we treated a limited number of patients, we obtained significantly higher RR and PFS-6 than those reported in a previous trial lacking molecular tumor analysis.

A clinical trial of bevacizumab, temozolomide, and radiation for newly diagnosed glioblastoma

J Neurosurg 116:341–345, 2012.DOI: 10.3171/2011.9.JNS11656

The presence of angiogenesis is a hallmark of glioblastoma (GBM). Vascular endothelial growth factor (VEGF), which drives angiogenesis, provides an additional target for conventional therapy. The authors conducted a prospective clinical trial to test the effectiveness of bevacizumab, an inhibitor of VEGF, in newly diagnosed GBM.

Methods. From 2006 through 2010, 51 eligible patients with newly diagnosed GBM were treated with involvedfield radiation therapy and concomitant temozolomide (75 mg/m2 daily for 42 days) along with bevacizumab (10 mg/ kg every 2 weeks), starting 29 days after surgery. This was followed by 6 cycles of adjuvant temozolomide therapy (150 mg/m2 on Days 1–7 of a 28-day cycle) with bevacizumab administered at 10 mg/kg on Days 8 and 22 of each 28-day cycle.

Results. The 6- and 12-month progression-free survival (PFS) rates were 85.1% and 51%, respectively. The 12- and 24-month overall survival (OS) rates were 85.1% and 42.5%, respectively. Grade III/IV toxicities were noted in 10 patients (19.6%). No treatment-related deaths were observed. Asymptomatic intracranial bleeding was noted in 5 patients.

Conclusions. The addition of bevacizumab to conventional therapy in newly diagnosed GBM appears to improve both PFS and OS in patients with newly diagnosed GBM, with acceptable morbidity. A shift toward diffuse relapse was noted in a significant number of patients. Ongoing Phase III clinical trials will show the true benefit of this antiangiogenic approach.

Bevacizumab Alone and in Combination With Irinotecan in Recurrent Glioblastoma

Journal of Clinical Oncology. DOI:10.1200/JCO.2008.19.8721

Purpose

We evaluated the efficacy of bevacizumab (Avastin TM), alone and in combination with irinotecan, in patients with recurrent glioblastoma in a phase II, multicenter, open-label, noncomparative trial.

Patients and Methods

One hundred sixty-seven patients were randomly assigned to receive bevacizumab 10 mg/kg alone or in combination with irinotecan 340 mg/m2 or 125 mg/m2 (with or without concomitant enzyme-inducing antiepileptic drugs, respectively) once every 2 weeks. Primary end points were 6-month progression-free survival and objective response rate, as determined by independent radiology review. Secondary end points included safety and overall survival.

Results

In the bevacizumab-alone and the bevacizumab-plus-irinotecan groups, estimated 6-month progression-free survival rates were 42.6% and 50.3%, respectively; objective response rates were 28.2% and 37.8%, respectively; and median overall survival times were 9.2 months and 8.7 months, respectively. There was a trend for patients who were taking corticosteroids at baseline to take stable or decreasing doses over time. Of the patients treated with bevacizumab alone or bevacizumab plus irinotecan, 46.4% and 65.8%, respectively, experienced grade  3 adverse events, the most common of which were hypertension (8.3%) and convulsion (6.0%) in the bevacizumab-alone group and convulsion (13.9%), neutropenia (8.9%), and fatigue (8.9%) in the bevacizumab-plus-irinotecan group. Intracranial hemorrhage was noted in two patients (2.4%) in the bevacizumab-alone group (grade 1) and in three patients (3.8%) patients in the bevacizumabplus-irinotecan group (grades 1, 2, and 4, respectively).

Conclusion

Bevacizumab, alone or in combination with irinotecan, was well tolerated and active in recurrent glioblastoma.