Inhibition of angiogenesis represents a promising new therapeutic strategy for treating primary malignant brain tumors. Lenalidomide, a potent analogue of the antiangiogenic agent thalidomide, has shown significant activity in several hematologic malignancies, and therefore we chose to explore its tolerability and activity in patients with primary central nervous system tumors.
A phase I interpatient dose escalation trial of lenalidomide in patients with recurrent primary central nervous system tumors was conducted.
Thirty-six patients were accrued to the study, of which 28 were evaluable for toxicity, the primary end point of the trial. We show that lenalidomide can be given safely up to doses of 20 mg/m(2), with the only toxicity being a probable increased risk of thromboembolic disease. Pharmacokinetic studies reveal good bioavailability, linear kinetics, and no effects of enzyme-inducing antiepileptic drugs on the metabolism of lenalidomide. No objective radiographic responses were seen in any of the treated patients. In the group of 24 patients with recurrent glioblastoma, the median time to tumor progression was <2 months and only 12.5% of patients were progression-free at 6 months.
Lenalidomide is well tolerated in patients with recurrent glioma in doses up to 20 mg/m(2). Treatment may be associated with an increased risk of thromboembolic disease. Preliminary data suggest that single agent activity may be limited in patients with recurrent glioblastoma at the doses evaluated although larger studies will be needed to confirm these observations.
"Its higher potency has led to several trials in which lenalidomide is currently under investigation as an anti-cancer agent, including multiple myeloma (Moehler, 2012), Crohn’s disease (Mansfield et al., 2007), and other solid tumors (Segler and Tsimberidou, 2012). When lenalidomide was evaluated in adults with recurrent primary CNS tumors in adults, as with thalidomide, these tumors showed no objective response to treatment with lenalidomide but instead increased hematological toxicity (Fine et al., 2007). However, in PBTC-018, a phase I trial of 51 pediatric patients with recurrent, refractory, or progressive CNS tumors, objective responses were seen primarily in children with low-grade gliomas. "
[Show abstract][Hide abstract] ABSTRACT: Brain tumors are the most common solid pediatric malignancy. For high-grade, recurrent or refractory pediatric brain tumors, radiation therapy (XRT) is an integral treatment modality. In the era of personalized cancer therapy, molecularly targeted agents have been designed to inhibit pathways critical to tumorigenesis. Our evolving knowledge of genetic aberrations in low-grade gliomas is being exploited with targeted inhibitors. These agents are also being combined with XRT to increase their efficacy. In this review, we discuss novel agents targeting three different pathways in low-grade gliomas, and their potential combination with XRT. B-Raf is a kinase in the Ras/Raf/MAPK kinase pathway, which is integral to cellular division, survival and metabolism. In low-grade pediatric gliomas, point mutations in BRAF (BRAF V600E) or a BRAF fusion mutation (KIAA1549:BRAF) causes overactivation of the MEK/MAPK pathway. Pre-clinical data shows cooperation between XRT and tagrgeted inhibitors of BRAF V600E, and MEK and mTOR inhibitors in the gliomas with the BRAF fusion. A second important signaling cascade in pediatric glioma pathogenesis is the PI3 kinase (PI3K)/mTOR pathway. Dual PI3K/mTOR inhibitors are poised to enter studies of pediatric tumors. Finally, many brain tumors express potent stimulators of angiogenesis. Several inhibitors of immunomodulators are currently being evaluated in in clinical trials for the treatment of recurrent or refractory pediatric central nervous system (CNS) tumors. In summary, combinations of these targeted inhibitors with radiation are currently under investigation in both translational bench research and early clinical trials. We summarize the molecular rationale for, and the pre-clinical data supporting the combinations of these targeted agents with other anti-cancer agents and XRT in pediatric gliomas. Parallels are drawn to adult gliomas, and the molecular mechanisms underlying the efficacy of these agents is discussed
Frontiers in Oncology 05/2013; 3:110. DOI:10.3389/fonc.2013.00110
"Despite these results enzastaurin showed a good safety and had a better hematologic toxicity profile . Many other antiangiogenics have also been tested in clinical trials              (Table 2). These studies showed encouraging results and are expected to improve the prognosis of HHG. "
[Show abstract][Hide abstract] ABSTRACT: Adult high grade gliomas (HGG) are the most frequent and fatal primary central nervous system (CNS) tumors. Despite recent advances in the knowledge of the pathology and the molecular features of this neoplasm, its prognosis remains poor. In the last years temozolomide (TMZ) has dramatically changed the life expectancy of these patients: the association of this drug with radiotherapy (RT), followed by TMZ alone, is the current standard of care. However, malignant gliomas often remain resistant to chemotherapy (CHT). Therefore, preclinical and clinical research efforts have been directed on identifying and understanding the different mechanisms of chemo-resistance operating in this subset of tumors,in order to develop effective strategies to overcome resistance. Moreover, the evidence of alterations in signal transduction pathways underlying tumor progression, has increased the number of trials investigating molecular target agents, such as anti-epidermal growth factor receptor (EGFR) and anti- vascular endothelial growth factor (VEGF) signaling. The purpose of this review is to point out the current standard of treatment and to explore new available target therapies in HGG.
Current cancer drug targets 07/2012; 12(8):1016-31. DOI:10.2174/156800912803251207 · 3.52 Impact Factor
"This drug is approved by the FDA for myelodysplastic syndrome with chromosome 5q deletion and multiple myeloma. Recently, lenalidomide has been performed for recurrent brain tumors in clinical trials [78, 97]. Fine et al. reported that lenalidomide was well tolerated; however, no objective responses were seen in a phase I study . "
[Show abstract][Hide abstract] ABSTRACT: Malignant gliomas have a poor prognosis despite advances in diagnosis and therapy. Although postoperative temozolomide and radiotherapy improve overall survival in glioblastoma patients, most patients experience a recurrence. The prognosis of recurrent malignant gliomas is dismal, and more effective therapeutic strategies are clearly needed. Antiangiogenesis is currently considered an attractive targeting therapy for malignant gliomas due to its important role in tumor growth. Clinical trials using bevacizumab have been performed for recurrent glioblastoma, and these studies have shown promising response rates along with progression-free survival. Based on the encouraging results, bevacizumab was approved by the FDA for the treatment of recurrent glioblastoma. In addition, bevacizumab has shown to be effective for recurrent anaplastic gliomas. Large phase III studies are currently ongoing to demonstrate the efficacy and safety of the addition of bevacizumab to temozolomide and radiotherapy for newly diagnosed glioblastoma. In contrast, several other antiangiogenic drugs have also been used in clinical trials. However, previous studies have not shown whether antiangiogenesis improves the overall survival of malignant gliomas. Specific severe side effects, difficult assessment of response, and lack of rational predictive markers are challenging problems. Further studies are warranted to establish the optimized antiangiogenesis therapy for malignant gliomas.
Journal of Oncology 01/2012; 2012(9):193436. DOI:10.1155/2012/193436
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