Phase II study of Gleevec plus hydroxyurea in adults with progressive or recurrent low-grade glioma

BACKGROUND:

We evaluated the efficacy of imatinib plus hydroxyurea in patients with progressive/recurrent low‐grade glioma.

METHODS:

A total of 64 patients with recurrent/progressive low‐grade glioma were enrolled in this single‐center study that stratified patients into astrocytoma and oligodendroglioma cohorts. All patients received 500 mg of hydroxyurea twice a day. Imatinib was administered at 400 mg per day for patients not on enzyme‐inducing antiepileptic drugs (EIAEDs) and at 500 mg twice a day if on EIAEDs. The primary endpoint was progression‐free survival at 12 months (PFS‐12) and secondary endpoints were safety, median progression‐free survival, and radiographic response rate.

RESULTS:

Thirty‐two patients were enrolled into each cohort. Eleven patients (17%) had before radiotherapy and 24 (38%) had received before chemotherapy. The median PFS and PFS‐12 were 11 months and 39%, respectively. Outcome did not differ between the histologic cohorts. No patient achieved a radiographic response. The most common grade 3 or greater adverse events were neutropenia (11%), thrombocytopenia (3%), and diarrhea (3%).

CONCLUSIONS:

Imatinib plus hydroxyurea was well tolerated among recurrent/progressive LGG patients but this regimen demonstrated negligible antitumor activity. Cancer 2012. © 2012 American Cancer Society.     

血管内皮生长因子在人脑胶质瘤中的表达及意义

目的研究人脑胶质瘤中血管内皮生长因子(vascularendothelialgrowthfactor,VEGF)的表达及临床病理意义.方法应用SABC免疫组化技术检测67例人脑胶质瘤、8例正常脑组织中VEGF表达.结果VEGF仅在肿瘤组织中表达,阳性表达率为83.6%,而在正常脑组织中无表达.VEGF与胶质瘤恶性程度(P<0.01)及肿瘤复发(P<0.01)相关.结论胶质瘤细胞能分泌VEGF,VEGF表达与肿瘤复发及预后有关.     

Somatostatin inhibits the production of vascular endothelial growth factor in human glioma cells

In various cell types, the neuro- and endocrine peptide somatostatin induces inhibitory and anti-secretory effects. Since somatostatin receptors, especially of the subtype sst2A, are constantly over-expressed in gliomas, we investigated the influence of somatostatin and the receptor subtype-selective peptide/non-peptide agonists octreotide and L-054,522 on the secretion of the most important angiogenesis factor produced by gliomas, vascular endothelial growth factor (VEGF). Cultivated cells from solid human gliomas of different stages and glioma cell lines secreted variable amounts of VEGF, which could be lowered to 25% to 80% by co-incubation with somatostatin or sst2-selective agonists (octreotide and L-054,522). These effects were dose-dependent at nanomolar concentrations. Stimulation with different growth factors (EGF, bFGF) or hypoxia considerably increased VEGF production over basal levels. Growth factor-induced VEGF synthesis could be suppressed to <50% by co-incubation with somatostatin or an sst2-selective agonist; this was less pronounced in hypoxia-induced VEGF synthesis. The effects were detected at the protein and mRNA levels. These experiments indicate a potent anti-secretory action of somatostatin or sst2 agonists on human glioma cells that may be useful for inhibiting angiogenesis in these tumors.     

Platelet-derived growth factor receptor as a prognostic marker and a therapeutic target for imatinib mesylate therapy in osteosarcoma

The purpose of this review was to determine whether imatinib mesylate (STI571, Gleevec) has a role in the treatment of osteosarcoma. The expression of platelet-derived growth factor (PDGF) receptor and its ligand was examined in a panel of surgical specimens obtained from 54 osteosarcoma patients, and then the expression was compared with prognosis. The effects of imatinib mesylate on growth and molecular events in 10 patient-derived osteosarcoma cell cultures were investigated. Immunohistochemical studies demonstrated frequent expression of PDGF-AA (80.4%) and PDGF-alpha receptor (79.6%) and their correlation with inferior event-free survival (P < .05). PDGF-B-B and PDGF-beta-receptor expressions were also frequent (75.4% and 86%, respectively); however, statistically significant inferior event-free survival was not demonstrated (P = .15). In vitro studies demonstrated that imatinib mesylate had a variable cytotoxic effect on various osteosarcoma primary cultures, with an IC(50) of 5.6 microM to 9.5 microM, and blocked the PDGF-induced intracellular signal transduction as well as inhibition of downstream Akt phosphorylation. Mitogen-activated protein kinase (MAPK) was constitutively activated despite PDGF stimulation and imatinib mesylate treatment in 7 of 10 osteosarcoma cultures, perhaps explaining uncontrolled proliferation and relative unresponsiveness to imatinib. Imatinib mesylate could not be viewed as having a role as a single agent at current conventional doses for the treatment of osteosarcoma. These findings predicted activity in osteosarcoma clinical trials and suggested that in vitro model systems predict clinical behavior and that PDGF and its receptor expression could potentially be used for determining prognosis of osteosarcoma.     

血管内皮因子及其受体与胶质瘤

 血管内皮生长因子及其受体在肿瘤的生长和转移过程中可能是最关键的刺激因子。在胶质瘤血管形成过程中起促进作用，它们的表达与胶质瘤的分级相关,且在抗胶质瘤血管生成治疗中是比较理想的靶位。     

QTc interval prolongation with vascular endothelial growth factor receptor tyrosine kinase inhibitors

Background:

Multi-targeted vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKIs) are known to cause cardiac toxicity, but the relative risk (RR) of QTc interval prolongation and serious arrhythmias associated with them are not reported.

Methods:

We conducted a trial-level meta-analysis of randomised phase II and III trials comparing arms with and without a US Food and Drug Administration-approved VEGFR TKI (sunitinib, sorafenib, pazopanib, axitinib, vandetanib, cabozantinib, ponatinib and regorafenib). A total of 6548 patients from 18 trials were selected. Statistical analyses were conducted to calculate the summary incidence, RR and 95% CIs.

Results:

The RR for all-grade and high-grade QTc prolongation for the TKI vs no TKI arms was 8.66 (95% CI 4.92–15.2, P<0.001) and 2.69 (95% CI 1.33–5.44, P=0.006), respectively, with most of the events being asymptomatic QTc prolongation. Respectively, 4.4% and 0.83% of patients exposed to VEGFR TKI had all-grade and high-grade QTc prolongation. On subgroup analysis, only sunitinib and vandetanib were associated with a statistically significant risk of QTc prolongation, with higher doses of vandetanib associated with a greater risk. The rate of serious arrhythmias including torsades de pointes did not seem to be higher with high-grade QTc prolongation. The risk of QTc prolongation was independent of the duration of therapy.

Conclusions:

In the largest study to date, we show that VEGFR TKI can be associated with QTc prolongation. Although most cases were of low clinical significance, it is unclear whether the same applies to patients treated off clinical trials.     

晚期恶性肿瘤血清VEGF含量测定的临床意义

Objective: To elucidate the clinical significance of serum vascular endothelial growth factor (VEGF) level in patients with advanced cancer. Methods: Enzyme linked immunosorbent assay (ELISA) was used to determine the serum VEGF concentration in 40 patients with advanced cancer [non-small cell lung cancer (NSCLC), esophageal cancer (EC) and nasopharyngeal carcinoma (NPC)] before and after chemotherapy and 10 healthy volunteers as control group. Results: The serum VEGF concentrations in 40 cases of advanced cancer patients were significantly higher than those of 10 healthy control cases [(477.07 ± 374.10 ) pg/mL vs (139.09 ± 133.41 ) pg/mL; P = 0.016]. The serum VEGF concentrations in patients with NSCLC, EC and NPC were (518.53 ± 378.99) pg/mL, (399.21 ± 393.69) pg/mL and (500.68 ± 348.48) pg/mL, respectively. The differences were all statistically significant as compared with healthy control group (P values were 0.011,0.044 and 0.019, respectively). The serum VEGF concentrations of the patients in response to chemotherapy was significantly lower than those of the same patients before they undergoing chemotherapy [(400.41 332.84) pg/mL vs (777.10 ± 666.01) pg/mL; P = 0.034]. Conclusion: The serum VEGF level might be a novel and promising tumor marker of advanced malignancies and a predictor of disease progression, prognosis and therapeutic efficacy.     

Phase I and pharmacokinetic study of vatalanib plus capecitabine in patients with advanced cancer

Angiogenesis inhibition is now a proven therapeutic strategy in treatment of several solid tumors. Vatalanib is a potent inhibitor of all known vascular endothelial growth factor receptor (VEGFR) tyrosine kinases. In view of the effectiveness of angiogenesis inhibitor therapy when combined with chemotherapy and the established role of capecitabine in treatment of colorectal and breast cancer, we undertook a phase I clinical trial of the combination of capecitabine and vatalanib with the goal of developing a combination oral regimen. The study objectives were to determine the maximally tolerated dose of vatalanib that could be safely administered daily with capecitabine given orally for 14 out of 21 days to patients with advanced cancer; to characterize the safety, tolerability, and pharmacokinetic profile of vatalanib given in combination with capecitabine; and to describe any pharmacokinetic interactions between the drugs. The study had an initial dose escalation phase followed by a dose expansion phase. During the dose escalation phase, cohorts of at least three patients each were treated with capecitabine and escalating doses of vatalanib until the maximally tolerated dose of vatalanib was determined. Vatalanib given continuously at a dose of 1,250 mg/day could be safely combined with capecitabine at a dose of 2,000 mg/m²/day given for 14 of 21 days. Dose-limiting toxicities of the combination included fatigue, hypertension, dizziness, and proteinuria. Vatalanib did not alter the pharmacokinetics of 5-FU, the active metabolite of capecitabine. Vatalanib and capecitabine can be safely combined without unexpected toxicities or significant pharmacokinetic interactions.     

Vascular endothelial growth factor expression is independent of hypoxia in human malignant glioma spheroids and tumours

We recently showed that severe hypoxia was not universally present adjacent to necrosis in human glioma xenografts and spheroids established from the M059K, M006, M006X, M006XLo and M010b cell lines. Using these glioma models, we wished to test whether oxygen serves as a regulator of cellular VEGF expression in situ. In situ hybridization (ISH) and immunohistochemistry (IHC) were used to detect vascular endothelial growth factor (VEGF) mRNA and protein expression in sections of glioma xenografts and spheroids in which hypoxic regions and regions with well-oxygenated necrosis were identified on contiguous sections by use of the hypoxia-specific marker, 3H-misonidazole. Independent validation of the presence of radiobiologically hypoxic cells in M006 xenografts was undertaken using the comet assay. Northern blotting analyses of monolayer cells demonstrated significant up-regulation of VEGF mRNA in the M006X line at oxygen concentrations of 6% and below. ISH analysis of VEGF mRNA showed unexpectedly strong staining for VEGF mRNA across the entire viable rim of M006X and M006XLo glioma spheroids. Similarly, in virtually all xenograft tumours of the M059K, M006 and M010b lines, VEGF ISH showed similar staining across all regions of healthy cells up to the border of necrosis. Only in one M006X tumour was there a suggestion of increased VEGF expression in cells adjacent to necrosis. IHC for VEGF showed good concordance with the ISH results. IHC analysis of the VEGF receptor flt-1 showed strong tumour cell staining in M006XLo glioma cells. In human glioma spheroids and xenograft tumours, regions of severe hypoxia do not correspond to areas of up-regulated VEGF expression; in fact, VEGF expression is quite uniform. Furthermore, this and our previous study demonstrate that levels of VEGF expression vary among sublines (M006, M006X and M006XLo) derived from a single human glioma specimen.     

Imatinib mesylate for targeting the platelet-derived growth factor beta receptor in combination with fluorouracil and leucovorin in patients with refractory pancreatic, bile duct, colorectal, or gastric cancer--a dose-escalation Phase I trial

BACKGROUND: In previous experimental models, because of its ability to inhibit the activity of platelet-derived growth factor beta receptor, imatinib decreased the interstitial fluid pressure and improved the delivery and efficacy of anticancer drugs, including fluorouracil. The objective of this Phase I study was to define the dose-limiting toxicity (DLT) and maximum tolerated dose (MTD) of imatinib in combination with fluorouracil and leucovorin in patients with chemotherapy-refractory gastrointestinal cancer. METHODS: A 3-patient cohort dose-escalating study design was used. Patients received leucovorin 200 mg/m2 followed by fluorouracil 2000 mg/m2 as a 24-hour infusion on Days 1 and 2 combined with imatinib on Days -4, -3, -2, -1, 1, 2, 3, and 4. Cycles were repeated every 2 weeks, and the imatinib dose was escalated from 300 mg daily to 700 mg daily in 100-mg steps. RESULTS: Thirty patients were enrolled at 5 dose levels. Frequent and dose-dependant National Cancer Institute Common Toxicity Criteria grade 1-4 adverse events with suspected relation to the treatment were anemia (43%), nausea (33%), fluid retention (27%), elevated serum gamma-glutamyl-transpeptidase (20%), and diarrhea. DLTs were severe neutropenia, central fluid retention, and severe nausea observed in 1 patient each, resulting in an MTD for imatinib of 600 mg per day. There were no differences in imatinib pharmacokinetics before or during chemotherapy. A minor response was observed; and signs of clinical activity, including the resolution of ascites and improvement in performance status, were noted in some patients. CONCLUSIONS: The combination of biweekly fluorouracil/leucovorin and imatinib 600 mg daily given in a week-on/week-off schedule was feasible and safe. Nausea and fluid retention represented the DLTs.     

Metronomic chemotherapy with daily, oral etoposide plus bevacizumab for recurrent malignant glioma: a phase II study

Background:

We evaluated bevacizumab with metronomic etoposide among recurrent malignant glioma patients in a phase 2, open-label trial.

Methods:

A total of59 patients, including 27 with glioblastoma (GBM) and 32 with grade 3 malignant glioma, received 10 mg kg⁻¹ bevacizumab biweekly and 50 mg m⁻² etoposide daily for 21 consecutive days each month. The primary end point was a 6-month progression-free survival, and secondary end points included safety and overall survival. Vascular endothelial growth factor (VEGF), VEGFR-2, carbonic anhydrase 9 (CA9) and hypoxia-inducible factor-2α (HIF-2α) were assessed semiquantitatively in archival tumours using immunohistochemistry and were correlated with outcome.

Results:

Among grade 3 and GBM patients, the 6-month progression-free survivals were 40.6% and 44.4%, the radiographic response rates were 22% and 37% and the median survivals were 63.1 and 44.4 weeks, respectively. Hypertension predicted better outcome among both grade 3 and GBM patients, whereas high CA9 and low VEGF were associated with poorer progression-free survival (PFS) among those with GBM. The most common grade ⩾3 adverse events included neutropaenia (24%), thrombosis (12%), infection (8%) and hypertension (3%). Two patients had asymptomatic, grade 1 intracranial haemorrhage and one on-study death occurred because of pulmonary embolism.

Conclusion:

Bevacizumab with metronomic etoposide has increased toxicity compared with previous reports of bevacizumab monotherapy. Its anti-tumour activity is similar to that of bevacizumab monotherapy or bevacizumab plus irinotecan. (ClinicalTrials.gov: NCT00612430).     

Prognostic but not predictive role of platelet‐derived growth factor receptors in patients with recurrent glioblastoma

Platelet‐derived growth factor receptor (PDGFR) signaling has been implicated in the pathogenesis of glioblastomas and represents a target for the tyrosine kinase inhibitor imatinib. To examine the prognostic or predictive role of PDGFRs in recurrent glioblastomas, expression was examined in tumor samples of 101 patients of CSTI571BDE40, a randomized trial comparing hydroxyurea monotherapy and a combination of hydroxyurea and imatinib. Furthermore, PDGFRα phosphorylation was investigated using in situ proximity ligation assay. PDGFRα protein was expressed in 33% of tumors and was associated with male sex, young age, presence of R132H mutated isocitrate dehydrogenase 1 protein and short median survival (142 vs. 187 days, p = 0.028). Tumor PDGFRα phosphorylation was also associated with short survival (p = 0.030). The subset of patients with PDGFRα positive glioblastoma did not have longer survival on treatment with hydroxyurea and imatinib compared with hydroxyurea monotherapy. In conclusion, both PDGFRα protein expression and phosphorylation status had a prognostic role in recurrent glioblastomas but did not define a group that showed benefit from the combination therapy consisting of hydroxyurea and imatinib.     

Phase II study of imatinib mesylate and hydroxyurea for recurrent grade III malignant gliomas

Purpose Recent reports demonstrate the activity of imatinib mesylate, an ATP-mimetic, tyrosine kinase inhibitor, plus hydroxyurea, a ribonucleotide reductase inhibitor, in patients with recurrent glioblastoma multiforme. We performed the current phase 2 study to evaluate this regimen among patients with recurrent WHO grade III malignant glioma (MG). Patients and method Patients with grade III MG at any recurrence, received imatinib mesylate plus hydroxyurea (500 mg twice a day) orally on a continuous, daily schedule. The imatinib mesylate dose was 500 mg twice a day for patients on enzyme inducing anti-epileptic drugs (EIAEDs) and 400 mg once a day for those not on EIAEDs. Clinical assessments were performed monthly and radiographic assessments were obtained at least every 2 months. The primary endpoint was 6-month progression-free survival (PFS) rate. Results Thirty-nine patients were enrolled. All patients had progressive disease after prior radiotherapy and at least temozolomide-based chemotherapy. The median number of episodes of prior progression was 2 (range, 1–7) and the median number of prior treatment regimens was 3 (range, 1–8). With a median follow-up of 82.9 weeks, 24% of patients were progression-free at 6 months. The radiographic response rate was 10%, while 33% achieved stable disease. Among patients who achieved at least stable disease at first evaluation, the 6-month and 12-month PFS rates were 53% and 29%, respectively. The most common grade 3 or greater toxicities were hematologic and complicated less than 4% of administered courses. Conclusion Imatinib mesylate plus hydroxyurea, is well tolerated and associated with anti-tumor activity in some patients with recurrent grade 3 MG. Supported by National Institutes of Health grant nos. 1-P50-CA108786-01, NS20023 and CA11898 and by grant no. MO1 RR 30 through the General Clinical Research Centers Program, National Center for Research Resources, National Institutes of Health.     

Lenvatinib in combination with golvatinib overcomes hepatocyte growth factor pathway‐induced resistance to vascular endothelial growth factor receptor inhibitor

Vascular endothelial growth factor receptor (VEGFR) inhibitors are approved for the treatment of several tumor types; however, some tumors show intrinsic resistance to VEGFR inhibitors, and some patients develop acquired resistance to these inhibitors. Therefore, a strategy to overcome VEGFR inhibitor resistance is urgently required. Recent reports suggest that activation of the hepatocyte growth factor (HGF) pathway through its cognate receptor, Met, contributes to VEGFR inhibitor resistance. Here, we explored the effect of the HGF/Met signaling pathway and its inhibitors on resistance to lenvatinib, a VEGFR inhibitor. In in vitro experiments, addition of VEGF plus HGF enhanced cell growth and tube formation of HUVECs when compared with stimulation by either factor alone. Lenvatinib potently inhibited the growth of HUVECs induced by VEGF alone, but cells induced by VEGF plus HGF showed lenvatinib resistance. This HGF‐induced resistance was cancelled when the Met inhibitor, golvatinib, was added with lenvatinib. Conditioned medium from tumor cells producing high amounts of HGF also conferred resistance to inhibition by lenvatinib. In s.c. xenograft models based on various tumor cell lines with high HGF expression, treatment with lenvatinib alone showed weak antitumor effects, but treatment with lenvatinib plus golvatinib showed synergistic antitumor effects, accompanied by decreased tumor vessel density. These results suggest that HGF from tumor cells confers resistance to tumor endothelial cells against VEGFR inhibitors, and that combination therapy using VEGFR inhibitors with Met inhibitors may be effective for overcoming resistance to VEGFR inhibitors. Further evaluation in clinical trials is warranted.     

子宫肌瘤中血管内皮生长因子及孕激素受体的表达

目的：研究血管内皮生长因子及孕激素受体在子宫肌瘤和正常子宫肌层中的表达及其在肌瘤发展中的作用。方法：应用免疫组织化学SP法检测40例子宫肌瘤组织和相应子宫肌层组织中血管内皮生长因子（VEGF）及孕激素受体（PR）表达。结果：子宫肌瘤血管内皮生长因子阳性率为77．5％,孕激素受体阳性率为87．5％,相应子宫肌层组织阳性率分别为12．5％、37．5％。两组间比较有显著性差异（P〈0．05）,血管内皮生长因子及孕激素受体表达之间存在明显关联性（P〈0．01）。结论：子宫肌瘤的发生发展可能与血管内皮生长因子及孕激素受体有关。     

前列腺癌细胞株VEGF及其受体KDR,bFGF及其受体FGFR2的表达及意义

目的:探讨人前列腺癌细胞株血管内皮细胞生长因子(VEGF)及其受体(KDR),碱性成纤维细胞生长因子(bFGF)及其受体(FGFR2)的表达,进一步阐明前列腺癌细胞中VEGF和bFGF的自分泌机制。方法:以小鼠成纤维细胞系L929作为对照,选取三种前列腺癌细胞株(PC3、LNcap和DU145),采用免疫组化染色、RT-PCR及Westernblot,检测VEGF及其受体KDR,bFGF及其受体FGFR2的表达。结果:三种前列腺癌细胞株(PC3、LNcap和DU145)中均有VEGF、KDR及bFGF、FGFR2的表达,但表达水平略有差别。结论:在前列腺癌的血管形成中可能存在VEGF和bFGF的自分泌机制。     

子宫肌瘤中血管内皮生长因子及孕激素受体的表达

目的:研究血管内皮生长因子及孕激素受体在子宫肌瘤和正常子宫肌层中的表达及其在肌瘤发展中的作用.方法:应用免疫组织化学SP法检测40例子宫肌瘤组织和相应子宫肌层组织中血管内皮生长因子(VEGF)及孕激素受体(PR)表达.结果:子宫肌瘤血管内皮生长因子阳性率为77.5%,孕激素受体阳性率为87.5%,相应子宫肌层组织阳性率分别为12.5%、37.5%.两组间比较有显著性差异(P<0.05),血管内皮生长因子及孕激素受体表达之间存在明显关联性(P<0.01).结论:子宫肌瘤的发生发展可能与血管内皮生长因子及孕激素受体有关.     

The vascular endothelial growth factor receptor tyrosine kinase inhibitor PTK787/ZK222584 inhibits growth and migration of multiple myeloma cells in the bone marrow microenvironment

Our prior studies show that multiple myeloma (MM) cell lines and patient cells express high-affinity vascular endothelial growth factor (VEGF) receptor (VEGFR) Flt-1 but not Flk-1/KDR. Moreover, these studies have shown that VEGF induces proliferation and migration of MM cells, and we have begun to delineate the signaling cascades mediating those sequelae. In this study, we examined the activity of PTK787/ZK 222584 (PTK787), a molecule designed to bind specifically to the tyrosine kinase domain of VEGFR and inhibit angiogenesis. We show that PTK787 acts both directly on MM cells and in the bone marrow microenvironment. Specifically, PTK787 (1-5 micro M) inhibits proliferation of MM cells by 50%, as assayed by [(3)H]thymidine uptake. This effect of PTK787 is dose dependent in both MM cell lines and patient cells that are both sensitive and resistant to conventional therapy. PTK787 enhances the inhibitory effect of dexamethasone on growth of MM cells and can overcome the protective effect of interleukin 6 (IL-6) against dexamethasone-induced apoptosis. PTK787 (1 micro M) also blocks VEGF-induced migration of MM cells across an extracellular matrix. Importantly, PTK787 also inhibits the increased MM cell proliferation and increased IL-6 and VEGF secretion in cultures of MM cells adherent to bone marrow stem cells. These findings therefore demonstrate that PTK787 both acts directly on MM cells and inhibits paracrine IL-6-mediated MM cell growth in the bone marrow milieu. The demonstrated anti-MM activity of PTK787, coupled with its antiangiogenic effects, provides the framework for clinical trials of this agent to overcome drug resistance and improve outcome in MM.