Concerns about anti-angiogenic treatment in patients with glioblastoma multiforme

BACKGROUND: The relevance of angiogenesis inhibition in the treatment of glioblastoma multiforme (GBM) should be considered in the unique context of malignant brain tumours. Although patients benefit greatly from reduced cerebral oedema and intracranial pressure, this important clinical improvement on its own may not be considered as an anti-tumour effect. DISCUSSION: GBM can be roughly separated into an angiogenic component, and an invasive or migratory component. Although this latter component seems inert to anti-angiogenic therapy, it is of major importance for disease progression and survival. We reviewed all relevant literature. Published data support that clinical symptoms are tempered by anti-angiogenic treatment, but that tumour invasion continues. Unfortunately, current imaging modalities are affected by anti-angiogenic treatment too, making it even harder to define tumour margins. To illustrate this we present MRI, biopsy and autopsy specimens from bevacizumab-treated patients. Moreover, while treatment of other tumour types may be improved by combining chemotherapy with anti-angiogenic drugs, inhibiting angiogenesis in GBM may antagonise the efficacy of chemotherapeutic drugs by normalising the blood-brain barrier function. SUMMARY: Although angiogenesis inhibition is of considerable value for symptom reduction in GBM patients, lack of proof of a true anti-tumour effect raises concerns about the place of this type of therapy in the treatment of GBM

Cyclooxygenase-2 inhibition inhibits c-Met kinase activity and wnt activity in colon cancer

Activity of receptor tyrosine kinases (RTK) in colorectal cancer (CRC) is associated with enhanced tumor growth and a poorer prognosis. In addition, cyclooxygenase-2 (COX-2) expression contributes to tumor growth and invasion. COX-2 inhibitors exhibit important anticarcinogenic potential against CRC, but the molecular mechanism underlying this effect and the relation with RTK signaling remain the subject of intense research effort. Therefore, the rapid effects of COX-2 inhibition in CRC on the complement of all cellular kinases were investigated using a kinase substrate peptide array, Western blotting, transfection, small interfering RNA assays, and CRC cell lines. The resulting alterations in the kinome profile revealed that celecoxib, a selective COX-2 inhibitor, impairs phosphorylation of substrates for the RTKs c-Met and insulin-like growth factor receptor, resulting in decreased downstream signaling. The decrease in c-Met activation is accompanied with an increase in glycogen synthase kinase 3beta kinase activity together with a rapid increase in phosphorylation of beta-catenin. In agreement, a significant reduction of beta-catenin-T-cell factor-dependent transcription is observed both with celecoxib and selective inhibition of c-Met phosphorylation by small molecules. Hence, corepression of c-Met-related and beta-catenin-related oncogenic signal transduction seems a major effector of celecoxib in CRC, which provides a rationale to use c-Met inhibitors and celecoxib analogous to target c-Met and Wnt signaling in a therapeutic setting for patients with CR

Bevacizumab in combination with radiotherapy and temozolomide for patients with newly diagnosed glioblastoma multiforme

Patients with a newly diagnosed glioblastoma multiforme (GBM) have a high risk of recurrent disease with a dismal outcome despite intensive treatment of sequential surgery and chemoradiotherapy with temozolomide (TMZ), followed by TMZ as a single agent. Bevacizumab (BV) may increase response rates to chemotherapy in the recurrent treatment setting of GBM. We hypothesized that a neoadjuvant treatment strategy for patients with newly diagnosed GBM using chemoradiotherapy plus BV would improve resectability and thus survival. We performed a phase II trial of the treatment strategy of BV plus chemoradiation to determine the safety of this combination in patients who had already undergone primary surgery for their GBM. After a biopsy (6 patients) or a resection (13 patients) of a newly diagnosed GBM, 19 patients received radiotherapy (30 fractions of 2 Gy) in combination with daily TMZ 75 mg/m(2) and BV 10 mg/kg on days 1, 14, and 28, followed by 6 monthly cycles of TMZ 150-200 mg/m(2) on days 1-5. The overall response rate was 26%. Three patients had a complete response after resection, and in two patients, a complete response after resection followed by chemoradiation plus BV was seen. No grade 3-4 toxicities were observed during combination treatment. The median progression-free survival was 9.6 months (95% confidence interval [CI]: 4.3-14.4 months). The median overall survival was 16 months (95% CI: 8.1-26.3 months), similar to a matched control group that received standard chemoradiotherapy from our institution. Combination of bevacizumab with radiotherapy and TMZ is safe and feasible in patients with newly diagnosed GBM, but because of low response rates, this treatment strategy does not favor a neoadjuvant approac

A single-arm, multicenter, open-label phase 2 study of lapatinib as the second-line treatment of patients with locally advanced or metastatic transitional cell carcinoma

BACKGROUND: The treatment of recurrent transitional cell carcinoma (TCC) remains an unmet clinical need. This study assessed lapatinib, a dual tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR) and HER-2, as second-line therapy in patients with locally advanced or metastatic TCC. METHODS: This was a single-arm, multicenter, open-label, prospective phase 2 study. Patients with TCC whose disease progressed on prior platinum-based chemotherapy received lapatinib until disease progression or unacceptable toxicity, with evaluations for response by Response Evaluation Criteria In Solid Tumors criteria performed every 8 weeks. The primary endpoint of the current study was objective tumor response rate. Secondary endpoints included safety, time to disease progression, and overall survival. RESULTS: Fifty-nine patients were enrolled in the study, 25 of whom (42%) could not be evaluated for response. The primary endpoint of an objective response rate (ORR) >10% was observed in 1.7% (95% confidence interval [95% CI], 0.0%-9.1%) of patients; however, 18 (31%; 95% CI, 19%-44%) patients achieved stable disease (SD). The median time to disease progression and overall survival (OS) were 8.6 weeks (95% CI, 8.0 weeks-11.3 weeks) and 17.9 weeks (95% CI, 13.1 weeks-30.3 weeks), respectively. Clinical benefit (ORR and SD) was found to be correlated with EGFR overexpression (P = .029), and, to some extent, HER-2 overexpression. The median OS was significantly prolonged in patients with tumors that overexpressed EGFR and/or HER-2 (P = .0001). Lapatinib was well tolerated. CONCLUSIONS: The study was considered to be negative because it did not meet its primary endpoint; however, further analysis demonstrated an improvement in OS in a subset of patients with tumors overexpressing EGFR and/or HER-2, which is encouraging and warrants further investigation

Chemotherapy, bevacizumab, and cetuximab in metastatic colorectal cancer.

Contains fulltext : 79995.pdf (publisher's version ) (Open Access)BACKGROUND: Fluoropyrimidine-based chemotherapy plus the anti-vascular endothelial growth factor (VEGF) antibody bevacizumab is standard first-line treatment for metastatic colorectal cancer. We studied the effect of adding the anti-epidermal growth factor receptor (EGFR) antibody cetuximab to a combination of capecitabine, oxaliplatin, and bevacizumab for metastatic colorectal cancer. METHODS: We randomly assigned 755 patients with previously untreated metastatic colorectal cancer to capecitabine, oxaliplatin, and bevacizumab (CB regimen, 378 patients) or the same regimen plus weekly cetuximab (CBC regimen, 377 patients). The primary end point was progression-free survival. The mutation status of the KRAS gene was evaluated as a predictor of outcome. RESULTS: The median progression-free survival was 10.7 months in the CB group and 9.4 in the CBC group (P=0.01). Quality-of-life scores were lower in the CBC group. The overall survival and response rates did not differ significantly in the two groups. Treated patients in the CBC group had more grade 3 or 4 adverse events, which were attributed to cetuximab-related adverse cutaneous effects. Patients treated with cetuximab who had tumors bearing a mutated KRAS gene had significantly decreased progression-free survival as compared with cetuximab-treated patients with wild-type-KRAS tumors or patients with mutated-KRAS tumors in the CB group. CONCLUSIONS: The addition of cetuximab to capecitabine, oxaliplatin, and bevacizumab resulted in significantly shorter progression-free survival and inferior quality of life. Mutation status of the KRAS gene was a predictor of outcome in the cetuximab group. (ClinicalTrials.gov number, NCT00208546.

Angiogenesis inhibitor DC101 delays growth of intracerebral glioblastoma but induces morbidity when combined with irradiation

The combination of irradiation with angiogenic inhibition is increasingly being investigated for treatment of glioblastoma multiforme (GBM). We investigated whether vascular endothelial growth factor receptor-2 (VEGFR-2) inhibitor DC101 affects morbidity and tumor growth in irradiated and non-irradiated intracerebral GBM-bearing mice, controlled with sham treatments. End-points were toxicity, morbidity and histology. Irradiation either or not combined, reduced tumor size strongly, whereas DC101 mono-treatment reduced tumor size by 64%. Irradiation delayed morbidity from 5.8 weeks in sham-treated mice to 10.3 weeks. Morbidity after combined treatment occurred after 5.9 weeks. Treatment with angiogenesis inhibitor DC101 delays tumor growth but it induces morbidity, by itself or combined with irradiation. (C) 2009 Elsevier Ireland Ltd. All rights reserve

Phase I pharmacokinetic study of the safety and tolerability of lapatinib (GW572016) in combination with oxaliplatin/fluorouracil/leucovorin (FOLFOX4) in patients with solid tumors

Purpose: This phase I study was designed to determine the optimally tolerated regimen (OTR), safety, and clinical activity of lapatinib in combination with FOLFOX4 [oxaliplatin/leucovorin/ 5-fluorouracil (5-FU)] in patients with solid tumors. Furthermore, the pharmacokinetics of lapatinib, oxaliplatin, and 5-FU when given alone and in combination were evaluated. Experimental Design: This study was conducted in two parts. Part 1 was designed to determine the OTR and part 2 was the pharmacokinetic part of the study. Lapatinib was administered once daily for the entire duration of the study. Leucovorin and oxaliplatin were given concurrently over 2 h as an i.v. infusion, after which 5-FU was given as a bolus followed by continuous infusion over 22 h on day 1.5-FU and leucovorin administration were repeated in an identical manner on day 2. Cycles were repeated every 2 weeks. Once the OTR was determined, it was to become the dose level for patients included in the pharmacokinetic part of the study. Results: A total of 34 patients was treated in this study. No dose-limiting toxicities were observed and the OTR was established at 1,500 mg/d lapatinib in combination with the standard FOLFOX4 regimen. Nonhematologic toxicities consisted mainly of nausea, diarrhea, vomiting, fatigue, neuropathy, and mucositis. The most important hematologic toxicity was neutropenia. No drug-drug interactions between lapatinib and the FOLFOX4 regimen were observed. Conclusion: Lapatinib can be safely administered in combination with the standard FOLFOX4 regimen. Further studies are warranted to explore the potential additive antitumor effect of lapatinib in combination with the FOLFOX4 regime