Posttreatment plasma VEGF levels may be associated with the overall survival of patients with advanced non-small cell lung cancer treated with bevacizumab plus chemotherapy

Association between continuous decrease of plasma VEGF-A levels and the efficacy of chemotherapy in combination with anti-programmed cell death 1 antibody in non-small cell lung cancer patients

OBJECTIVES

Vascular endothelial growth factor-A (VEGF-A) plays important roles in tumor immune suppression and thus correlates with the efficacy of anti-programmed cell death-1/ligand 1 (anti-PD-1/PD-L1) antibodies. We aimed to determine the association between change in plasma VEGF-A levels and the efficacy of chemotherapy combined with anti-PD-1/PD-L1 antibodies (chemo-PD1) in non-small cell lung cancer (NSCLC) patients.

METHODS

We included NSCLC patients treated with chemo-PD1. Plasma VEGF-A levels were measured at baseline (Pre) and days 7 (D7) and 14 (D14) after the initiation of chemo-PD1. Continuous VEGF-A decrease was determined by comparing Pre with the median value of maximum change rate of posttreatment VEGF-A as cutoff. Patients whose change rates of VEGF-A at both D7 and D14 were consistently lower than the cutoff value were classified into the VEGF-A decrease group, whereas those whose VEGF-A at D7 or D14 were higher than the cutoff level were classified into the VEGF-A no-decrease group. The primary outcome was progression-free survival (PFS).

RESULTS

A total of 32 patients were evaluated. The median Pre VEGF-A levels was 49 (range, 13-257). The median change rate of VEGF-A at D7 and D14 was -25.6% (range, -77.5-376.9) and -42.3% (range, -100-138.5) respectively. The cutoff value of posttreatment VEGF-A change rate was -9.3%. The PFS was significantly longer in the VEGF-A decrease group than that in the VEGF-A no-decrease group (median, not reached vs 2.4 months; p = 0.017).

CONCLUSIONS

Continuous decrease of plasma VEGF-A levels during treatment may be associated with the efficacy of chemo-PD1.

Elevated GPC3 level promotes cell proliferation in liver cancer

The aim of the present study was to investigate the biological role of glypican 3 (GPC3), and to identify its mechanism and clinical significance in the carcinogenesis of liver cancer. A total of 114 patients with liver cancer were involved. Their clinical data, hematoxylin and eosin-stained and Antigen Ki-67 protein (Ki-67) and GPC3 immunohistochemically-stained liver cancer tissue sections were analyzed to evaluate the correlation between the liver cancer proliferation, differentiation and GPC3 expression. Fluorescence microscopy, western blotting, MTT and reverse transcription quantitative polymerase chain reaction (RT-qPCR) assays were performed in HepG2 and HLE cell lines to investigate the potential mechanisms of action. Among the 114 patients with liver cancer enrolled in the present study, 12 exhibited well-differentiated liver cancer, of which 6 (50%) were positive for GPC3. A total of 30 cases exhibited poorly differentiated liver cancer; 26 (87%) of these expressed GPC3 and 11 cases (37%) demonstrated strong positive expression levels. The other 72 liver cancer cases were moderately differentiated; 75% (54/72) of these expressed GPC3 and 12.5% (9/72) exhibited strong positive expression levels. There was a significant association between the levels of GPC3 expression and liver cancer differentiation (χ²=16.306, P=0.008). Ki-67 staining as the criteria of the liver cancer cell proliferation index also indicated a cross correlation between liver cancer proliferation and GPC3 levels. Among the 39 liver cancer samples with a cell proliferation index <5%, only 2.6% (1/39) exhibited strong positive GPC3 staining, but of the 16 cases with a high cell proliferation index >50%, 6 exhibited strong GPC3 staining (37.5%). The difference of cell proliferation indexes between cancer cells were well, moderate and poorly differentiated, and was markedly significant (χ²=26.334, P=0.002), and suggested that liver cancer cell proliferation was positively correlated with GPC3 expression (r=0.316, P=0.001). Consistently, in vitro analysis indicated that GPC3 promoted HepG2 and HLE cell growth, which was more apparent in HepG2 cells. The RT-qPCR results indicated that GPC3 promoted proliferation through the Hedgehog (Hh) pathway in HepG2 cells, but not in HLE cells. In the present study, it was demonstrated that patients with liver cancer with higher GPC3 levels exhibited poorer differentiation and higher proliferation levels. In vitro GPC3 may promote liver cancer cell lines proliferation through the Hh pathway.

JAK2 inhibitor combined with DC-activated AFP-specific T-cells enhances antitumor function in a Fas/FasL signal-independent pathway

Objective

Combination therapy for cancer is more effective than using only standard chemo- or radiotherapy. Our previous results showed that dendritic cell-activated α-fetoprotein (AFP)-specific T-cells inhibit tumor in vitro and in vivo. In this study, we focused on antitumor function of CD8⁺ T-cells combined with or without JAK2 inhibitor.

Methods

Proliferation and cell cycle were analyzed by CCK-8 and flow cytometry. Western blot was used to analyze the expression level of related protein and signaling pathway.

Results

We demonstrated reduced viability and induction of apoptosis of tumor cells with combination treatment. Intriguingly, cell cycle was blocked at the G1 phase by using AFP-specific CD8⁺ T-cells combined with JAK2 inhibitor (AG490). Furthermore, an enhanced expression of BAX but no influence on Fas/FasL was detected from the tumor cells.

Conclusion

These results indicate a Fas/FasL-independent pathway for cellular apoptosis in cancer therapies with the treatment of AFP-specific CD8⁺ T-cells combined with JAK2 inhibitor.

Antitumor effect of recombinant human endostatin combined with cisplatin on rats with transplanted Lewis lung cancer

OBJECTIVE

To observe the antitumor effect and mechanism of recombinant human endostatin (Endostar) injection in tumor combined with intraperitoneal injection of cisplatin on subcutaneous transplanted Lewis lung cancer in rats.

METHODS

A total of 30 C57 rats were selected, and the monoplast suspension of Lewis lung cancer was injected into the left axilla to prepare the subcutaneous transplanted tumor models in the axilla of right upper limb. The models were randomly divided into Groups A, B, and C. Medication was conducted when the tumor grew to 400 mm(3). Group A was the control group without any interventional treatment. Group B was injected with Endostar 5 mg kg(-1) d(-1) for 10 d. Group C was given the injection of Endostar 5 mg kg(-1) d(-1) combined with intraperitoneal injection of cisplatin 5 mg kg(-1) d(-1) for 10 d. All the rats in three groups were executed the day after the 10 d medication and the tumor was taken off for measurement of volume and mass changes and calculation of antitumor rate, after which the vascular endothelial growth factor (VEGF) concentration in rats' plasma was determined by ELISA. The tumor tissues were cut for the preparation of conventional biopsies. After hematoxylin-eosin staining, the pathologic histology was examined to observe the structures of tumor tissues, VEGF score and microvessel density (MVD) in each group.

RESULTS

The volume and mass of tumor in Groups B and C were significantly lower than Group A (P < 0.05) while the tumor volume and mass in Group C were significantly lower than Group B (P < 0.05). The antitumor rate in Group C was significantly higher than Group B (P < 0.05), but the tumor VEGF score, MVD and plasma VEGF level in Group C were significantly lower than Groups A and B (P < 0.05). In Group B, the tumor VEGF score, MVD and plasma VEGF level were significantly lower than Group A (P < 0.05). The microscopic image of Group C showed that its number of active tumor cells and the blood capillary around tumor was significantly smaller than that of Groups A and B, and meanwhile atrophy and liquefactive necrosis were seen in local tumor.

CONCLUSIONS

Endostar injection combined with intraperitoneal injection of cisplatin is effective in reducing tumor VEGF score and MVD of transplanted tumor tissues in rats with Lewis lung cancer to obstruct the nutrient supply of tumor cells and kill tumor cells, so that the inhibition of tumor cell proliferation and metastasis can be achieved with a remarkable effect.

Bevacizumab: a review of its use in advanced cancer

The humanized monoclonal antibody bevacizumab (Avastin(®)) has been available in the EU since 2005. Results of phase III trials demonstrate that adding intravenous bevacizumab to antineoplastic agents improves progression-free survival and/or overall survival in patients with advanced cancer, including when used as first- or second-line therapy in metastatic colorectal cancer, as first-line therapy in advanced nonsquamous non-small cell lung cancer, as first-line therapy in metastatic renal cell carcinoma, as first-line therapy in metastatic breast cancer, and as first-line therapy in epithelial ovarian, fallopian tube or primary peritoneal cancer or in recurrent, platinum-sensitive or platinum-resistant disease. Results of these studies are supported by the findings of routine oncology practice studies conducted in real-world settings. The tolerability profile of bevacizumab is well defined and adverse events associated with its use (e.g. hypertension, proteinuria, haemorrhage, wound healing complications, arterial thromboembolism, gastrointestinal perforation) are generally manageable. In conclusion, bevacizumab remains an important option for use in patients with advanced cancer.

Lower Ras expression as an independent predictor of patient outcomes in lung cancer treated with bevacizumab plus chemotherapy

The objective of this study was to analyze the predictive roles of VEGF/KDR/Ras/MAPK gene expression in patients with advanced non-small-cell lung cancer (NSCLC) treated with bevacizumab plus chemotherapy. Twenty-five patients participating in an open-label phase IV trial (SAiL, MO19390) with available tumor tissues were analyzed. The mRNA expression levels of VEGF, kinase insert domain receptor (KDR), Ras, and mitogen-activated protein kinase (MAPK) in tumor tissues were detected using real-time quantitative PCR methods. The relationships between gene expression and disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) were assessed. Patients with lower Ras expression had a longer PFS and OS than patients with higher expression (median PFS, 9.9 vs 5.5 months, χ(2)=3.944, P=0.047; OS, 19.3 vs 7.1 months, χ(2)=9.384, P=0.002). The PFS and OS of patients with lower and higher MAPK expression exhibited a marginal and significant difference (median PFS, 9.9 vs 5.5 months, χ(2)=3.464, P=0.063; OS, 19.3 vs 9.7 months, χ(2)=5.298, P=0.021), respectively. Multivariate analyses using Cox's proportional hazards model showed that Ras is an independent predictor of OS (χ(2)=9.384, P=0.002). No differences in DCR were found according to Ras expression level. The results indicate that Ras is an independent predictor of OS. Thus, patients with lower Ras expression are most likely to benefit from bevacizumab plus chemotherapy treatment regimen. Patients with higher levels of Ras should receive other inhibitors that target Ras. The results also suggest that gene therapies that decrease RAS expression combined with bevacizumab may improve lung cancer treatment. Although there is a very important implication to patient selection in the target therapy, the data in this study are very preliminary owing to the too small sample size. Therefore, further research involving large numbers of patients and a prospective assessment of low and high RAS mRNA expressions getting the same treatments need to be done before conclusions can be made.

High circulating VEGF level predicts poor overall survival in lung cancer

PURPOSE

Vascular endothelial growth factor (VEGF) is considered as the best-validated key regulator of angiogenesis, while the prognostic role of circulating VEGF in lung cancer remains controversial. We conducted a meta-analysis to evaluate the prognostic role of circulating VEGF.

METHODS

Nineteen studies with a total number of 2,890 patients were analyzed in our meta-analysis. Hazard ratios (HRs) and their 95 % confidence intervals (CIs) were used to quantify the predictive ability of circulating VEGF on survival.

RESULTS

The pooled HR of all 17 studies evaluating overall survival (OS) was 1.29 (95 % CI 1.19-1.40, p < 0.001), indicating high circulating VEGF predicted poor OS. When grouped by disease stages, the pooled HRs were 0.97 (95 % CI 0.47-1.47, p < 0.001) for operable stage and 1.34 (95 % CI 1.18-1.49, p < 0.001) for inoperable stage. The pooled HRs were 1.28 (95 % CI 1.15-1.42, p < 0.001) for serum and 1.31 (95 % CI 1.13-1.49, p < 0.001) for plasma, when categorized by blood sample. Meta-analysis of circulating VEGF related to progression-free survival (PFS) was performed in 7 studies, and the pooled HR was 1.03 (95 % CI 0.96-1.09).

CONCLUSIONS

Our results indicate that high level of circulating VEGF predicts poor OS in lung cancer, yet it does not predict poor PFS.

Monoclonal antibodies in lung cancer

INTRODUCTION

Lung cancer is the leading cause of cancer death worldwide. As clinical benefits to conventional cancer therapies are still formidable, there is an urgent need for novel agents and approaches to improve the overall clinical outcomes for patients with lung cancer.

AREAS COVERED

This article reviews the current understanding of targeted therapy for lung cancer with monoclonal antibodies (mAbs), mainly bevacizumab and cetuximab. The results from several key clinical trials validating the effectiveness and safety of bevacizumab and cetuximab, the relation of cancer biomarkers, the polymorphic correlation of targeted genes with the therapeutic outcome of mAb-based treatment, as well as the impact of Biomarker-integrated Approaches of Targeted Therapy for Lung Cancer Elimination (BATTLE) trial on personalised treatment of lung cancer are discussed.

EXPERT OPINION

The addition of bevacizumab or cetuximab to chemotherapy has shown promising benefits to the patients with non-small-cell lung cancer. However, the overall benefits of mAb-based targeted therapy to lung cancer patients vary among individuals. It is therefore necessary to define reliable predictive biomarkers in an effort to better identify patients who are most likely to benefit from treatment with these novel agents in lung cancer.

sVEGF R1 and Tie-2 levels during chemotherapy of lung cancer patients

Angiogenesis plays important role in tumor growth and development. Protein ligands and their receptor tyrosine kinases are crucial in tumor related angiogenesis. Ligand/receptor systems such as vascular endothelial growth factor (VEGF), and tyrosine kinase with immunoglobulin-like and epidermal growth factor homology domains (Tie) family play important role in this phenomenon. The aim of this study was to evaluate the concentration of soluble receptor of VEGF (sVEGF R1) and Tie-2 domain in plasma of lung cancer patients before and after chemotherapy. Forty four lung cancer patients, 11 with small lung cancer (SCLC), 5 females and 6 males (mean age 60.2, range 39-72 years), and 33 patients with non-small cell lung cancer (N-SCLC), 6 females and 27 males (mean age 61.9, range 42-78 years) received four courses of chemotherapy. Control group consisted of 44 patients with COPD, 4 females and 40 males (mean age 37.1, 18-60 years). In all cases clinical partial response was achieved. Both sVEGF R1 and Tie-2 concentrations were elevated in cancer group before treatment compared with control: sVEGF (pg/ml): 60.7 and 66.2 vs. 48.8 and Tie-2 (ng/ml): 37.3 and 37.5 vs. 30.7 in SCLC and N-SCLC vs. C, respectively. Treatment decreased sVEGF R1 (pg/ml): 66.7 vs. 11.6 (p < 0.05) and 66.2 vs. 14.39 (p < 0.001), and Tie-2 (ng/ml): 37.3 vs. 26.3 (p < 0.05) and 37.5 vs. 25.7 (p < 0.001) in SCLC and N-SCLC, respectively. We conclude that VEGF R1and Tie-2 receptors may play important role in lung cancer development and their receptor concentrations may reflect the patients' response to treatment.

Phase-I/II study of bortezomib in combination with carboplatin and bevacizumab as first-line therapy in patients with advanced non-small-cell lung cancer

BACKGROUND

This study aimed to establish the maximum tolerated dose (MTD) of weekly bortezomib in combination with fixed standard doses of carboplatin and bevacizumab, and to estimate the efficacy (response rate and progression free survival [PFS]) and safety of combination therapy with carboplatin, bortezomib, and bevacizumab as first-line therapy in patients with advanced non-small-cell lung cancer (NSCLC).

METHODS

Patients were assigned to three dose levels of weekly bortezomib with the fixed standard doses of carboplatin AUC 6 and bevacizumab (15 mg/kg) every 3 weeks using a standard phase-I design. Bortezomib doses were 1.3 mg/m, 1.6 mg/m, and 1.8 mg/m weekly on day 1 and day 8 of every 3-week cycle. A maximum of six cycles was administered. Patients with complete, partial response or stable disease were continued on single-agent bevacizumab (15 mg/kg every 3 weeks) as maintenance therapy. In phase II, either level III or MTD was administered to evaluate the efficacy and safety of the combination in first-line treatment of advanced NSCLC.

RESULTS

Sixteen patients were enrolled (three, four, and nine patients in dose level I, II, and III, respectively). There was no predefined dose limiting toxicity in cycle 1 in all 16 patients. The recommended phase-II dose is bortezomib 1.8 mg/m weekly on day 1 and day 8 in combination with carboplatin AUC 6 and bevacizumab 15 mg/kg on every 21-day cycle. Totally 9 patients were treated at the recommended phase-II dose level. The most common treatment related grade-3/4 toxicities during the subsequent cycles were thrombocytopenia (58%), lymphopenia (25%), neutropenia (12%), and diarrhea (25%). The grade-1/2 neuropathy was seen in 7 out of 16 patients (44%). The response rate, PFS, and overall survival in all patients were 37.5% (95%CI 13.8%-61.2%), 5.0 months (95%CI: 3.1-8.4), 9.9 months (95% CI: 8.2-14.1), and among the 9 patients in phase-II portion are 44% (95%CI 15.3%-77.3%), 5.5 months (95%CI: 3.1-2.2) and 10.9 months (95%CI: 8.0-14.1).

CONCLUSION

The recommended phase-II dose for this combination is: carboplatin AUC 6, bevacizumab 15 mg/kg on day 1 and bortezomib 1.8 mg/m on day 1 and day 8 on every 21-day cycle. The regimen was very well tolerated with interesting clinical activity in first-line treatment of NSCLC.

A phase I trial of PX-12, a small-molecule inhibitor of thioredoxin-1, administered as a 72-hour infusion every 21 days in patients with advanced cancers refractory to standard therapy

PURPOSE

This phase I trial assessed the safety, dose limiting toxicity (DLT) and pharmacodynamics of PX-12 in adult patients with advanced refractory cancers.

METHODS

PX-12 was administered to sequential cohorts as a 72-h infusion utilizing a portable infusion pump on days 1, 2, and 3 of a 21-day cycle at a starting dose level of 300 mg/m(2)/day and escalating dose levels till DLT was observed. Plasma thioredoxin (Trx-1), vascular endothelial growth factor (VEGF) and FGF-2 (fibroblast growth factor) levels were measured predose and during infusion of PX-12.

RESULTS

Patients (n = 14) were enrolled to the following dose cohorts, 300 mg/m(2) (n = 3), 400 mg/m(2) (n = 10) and 500 mg/m(2) (n = 1). Common grade 1/2 toxicities included fatigue, taste alteration and odor caused by expired drug metabolite. DLTs were one episode each of grade 3 hypoxia at the 400 mg/m(2) and grade 3 reversible pneumonitis at the 500 mg/m(2) dose levels. Best response was stable disease in a patient with rectal cancer. Predose Trx-1 levels (n = 12) ranged from 5.1 to 30.0 ng/mL (median 12.6 ng/mL).

CONCLUSION

PX-12 administered at 400 mg/m(2)/day by 72-hour infusion appears safe and tolerable. Inhibition of thioredoxin is a strategy worth evaluation with next generation of inhibitors.