Al's Comment:
I love this type of project. These researchers tried adding the drug valganciclovir (Valcyte) to the treatment plan for recurrent gbm patients who were using Avastin. The concept behind this is that most or all GBMs have a virus in them called Cytomegalovirus. (Some researchers disagree and say NONE of the GBMs they tested have the virus). It is not known if the virus triggers the tumor to form, or if it makes the tumor more aggressive, or if it is just a bystander and doesn't affect the tumor. Valcyte is an oral antiviral drug which slows or stops the virus from reproducing. This study (although it is too small to be considered proof) shows that adding Valcyte increases overall survival and progression free survival. This implies that the CMV plays a role in making the tumor grow.
Using it in combination with Avastin was a great idea, since Avastin also slows down the tumor growth using a different pathway (VEGF). I think that hitting either pathway alone allows the tumor to find a way around the treatment, but hitting it on multiple pathways may be the answer. Perhaps adding 1 or 2 other treatments, hitting the tumor from another pathway, may make even a larger difference.
Posted on: 02/21/2016
Mol Clin Oncol. 2016 Feb;4(2):154-158. Epub 2015 Dec 4.
Valganciclovir and bevacizumab for recurrent glioblastoma: A single-institution experience.
Peng C1, Wang J2, Tanksley JP1, Mobley BC3, Ayers GD4, Moots PL1, Clark SW1.
Author information:
1Department of Neurology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
2Department of Neurosurgery, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
3Department of Pathology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
4Center for Quantitative Sciences, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
Abstract
Prolonged treatment with adjuvant valganciclovir has been shown in one retrospective study to exert a significant effect on overall survival (OS) in newly diagnosed patients with glioblastoma multiforme (GBM). However, studies evaluating the effectiveness of valganciclovir in the treatment of recurrent GBM have not been performed. We evaluated the effect of valganciclovir in the recurrent setting in combination with bevacizumab therapy. A retrospective analysis was performed on patients treated for recurrent GBM with off-label valganciclovir and bevacizumab at Vanderbilt University. We identified 13 patients who received valganciclovir plus bevacizumab at some point during their treatment, 8 of whom were started on valganciclovir and bevacizumab concurrently upon first recurrence, whereas 5 had valganciclovir added to their bevacizumab regimen prior to a second recurrence. of these patients, 12 were pathologically confirmed to have GBM, and 1 patient was diagnosed with gliosarcoma. We also identified an institutional cohort of 50 patients who had not been exposed to valganciclovir, but were treated with bevacizumab for first recurrence. The progression-free survival (PFS) at 6 months (PF6) and median OS (mOS) in the valganciclovir plus bevacizumab group was 62% and 13.1 months, respectively, for all 13 patients, and 50% and 11.3 months, respectively, for the 8 concurrently treated patients. In the institutional bevacizumab cohort, the PF6 and mOS were 34% and 8.7 months, respectively. In this retrospective analysis, valganciclovir in combination with bevacizumab exhibited a trend toward improved survival in patients with recurrent GBM. However, given the small sample size and the retrospective nature of this study, a larger prospective study is required to confirm these results.
PMID: 26893852 [PubMed]
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