Motesanib, or open-label bevacizumab, in combination with paclitaxel, as first-line treatment for HER2-negative locally recurrent or metastatic breast cancer: a phase 2, randomised, double-blind, placebo-controlled study

Vascular Endothelial Growth Factor Receptors [VEGFR] as Target in Breast Cancer Treatment: Current Status in Preclinical and Clinical Studies and Future Directions

Breast cancer [BC] is one of the most common cancers among women, one of the leading causes of a considerable number of cancer-related death globally. Among all procedures leading to the formation of breast tumors, angiogenesis has an important role in cancer progression and outcomes. Therefore, various anti-angiogenic strategies have developed so far to enhance treatment's efficacy in different types of BC. Vascular endothelial growth factors [VEGFs] and their receptors are regarded as the most well-known regulators of neovascularization. VEGF binding to vascular endothelial growth factor receptors [VEGFRs] provides cell proliferation and vascular tissue formation by the subsequent tyrosine kinase pathway. VEGF/VEGFR axis displays an attractive target for anti-angiogenesis and anti-cancer drug design. This review aims to describe the existing literature regarding VEGFR inhibitors, focusing on BC treatment reported in the last two decades.

Risk of hypertension with anti-VEGF monoclonal antibodies in cancer patients: a systematic review and meta-analysis of 105 phase II/III randomized controlled trials

We performed a meta-analysis to fully investigate the hypertension of anti-VEGF mAbs in cancer patients. Databases were searched for randomized controlled trials (RCTs) treated with anti-VEGF mAbs till January 2021. The relevant RCTs in cancer patients treated with anti-VEGF mAbs were retrieved and the systematic evaluation was conducted. One hundred and five RCTs and 65358 patients were included. Our study suggests that anti-VEGF mAbs significantly increased the risks of all-grade (RR, 3.22; 95%CI, 2.83-3.65; p < 0.00001; I²=71%) and high-grade (RR, 6.15; 95%CI, 5.58-6.78; p < 0.00001; I²=48%) hypertension in cancer patients. Those risks may be dependent on drug type. Icrucumab did not association with an increased risk of hypertension. The RR of hypertension did not vary significantly according to the type of cancer, line of therapy, and treatment duration. The available data suggested that the use of anti-VEGF mAbs were associated with a significantly increased risk of hypertension.

A Systematic Review and Meta-Analysis of Bevacizumab in First-Line Metastatic Breast Cancer: Lessons for Research and Regulatory Enterprises

BACKGROUND

The US Food and Drug Administration's accelerated approval and later withdrawal of bevacizumab in patients with metastatic breast cancer (mBC) is a seminal case for ongoing debates about the validity of using progression-free survival (PFS) as a surrogate measure for overall survival (OS) in cancer drug approvals. We systematically reviewed and meta-analyzed the evidence around bevacizumab's regulatory approval and withdrawal in mBC.

METHODS

We searched for all published phase II or III clinical trials testing bevacizumab as a first-line therapy for patients with mBC. Data were extracted on trial demographics, interventions, and outcomes. Descriptive analysis was stratified by whether the trial was initiated before, during, or after the accelerated approval. We used a cumulative random-effects meta-analysis to assess the evolution of evidence of the effect of bevacizumab on PFS and OS. We estimated the association between the trial-level PFS and OS effect using a nonlinear mixed-regression model.

RESULTS

Fifty-two studies were included. Trial activity dramatically dropped after the accelerated approval was withdrawn. Eight clinical trials reported hazard ratios (hazard ratios) and were meta-analyzed. The cumulative hazard ratio for PFS was 0.72 (95% CI = 0.65 to 0.79), and the cumulative hazard ratio for OS was 0.90 (95% CI = 0.80 to 1.01). The regression model showed a statistically nonsignificant association between PFS benefit and OS benefit (β = 0.43, SE = 0.81).

CONCLUSION

The US Food and Drug Administration's decision-making in this case was consistent with the evolving state of evidence. However, the fact that seven clinical trials are insufficient to conclude validity (or lack thereof) for a trial-level surrogate suggests that it would be more efficient to conduct trials using the more clinically meaningful endpoints.

Efficacy of bevacizumab combined with chemotherapy in the treatment of HER2-negative metastatic breast cancer: a network meta-analysis

Background

It is not known what combination of bevacizumab and chemotherapy agents is the best therapeutic regimen. Comparative study results among the efficacies of bevacizumab plus chemotherapy remain controversial in patients with HER2-negative metastatic breast cancer.

Methods

We searched Pubmed, Embase, and Cochrane Library Central Resister of Controlled Trials through were July 2019 for randomized controlled trials that evaluated the efficacy of bevacizumab plus chemotherapy in HER2-negative metastatic breast cancer. Data on included study characteristics, outcomes, and risk of bias were abstracted by two reviewers.

Results

A total of 16 RCT studies involving 5689 patients were included. The results showed that bevacizumab (Bev) - taxanes (Tax) - capecitabine (Cap) has highest-ranking and is probably more effective for prolonging progression-free survival (PFS) than Tax, Cap, Bev-Tax and Bev-Cap, which was no convincing differences among Bev-Cap-vinorelbine, Bev-Tax-everolimus, Bev-Tax-trebananib, Bev-exemestane, Bev-Cap-cyclophosphamide in Bev-containing regimens. For overall response rate (ORR), Bev-Tax-Cap is superior to Tax, Cap and Bev-Cap, while Bev-Tax-trebananib is superior to Cap. The cumulative probability ranking showed that Bev-Tax-Cap or Bev-Tax-trebananib may have best pathological response rate in HER2-negative metastatic breast cancer.

Conclusion

Our results provide moderate quality evidence that bevacizumab-taxanes-capecitabine maybe the most effective bevacizumab plus chemotherapy on PFS and ORR in HER2-negative metastatic breast cancer, however it should be also considered that bevacizumab may add toxicity to chemotherapy and whether improve overall survival (OS) or not.

Risks and benefits of bevacizumab combined with chemotherapy for advanced or metastatic breast cancer: a meta-analysis of randomized controlled trials

BACKGROUND

The combination of bevacizumab and chemotherapy has greatly improved progression-free survival (PFS) and objective response rate (ORR) in HER2-negative metastatic breast cancer in many pivotal trials. However, risk-benefit balance related to bevacizumab addition could not be confirmed because of a lack of overall survival (OS) improvement. Therefore, we conducted a meta-analysis to evaluate multiple endpoints pertaining to bevacizumab use in metastatic breast cancer (MBC) treatment.

METHODS

We searched PubMed and Cochrane Library databases and included seven studies in our meta-analysis in which bevacizumab combined with chemotherapy was compared with chemotherapy alone in MBC.

RESULTS

Compared to the chemotherapy-alone group, the combination treatment group had significantly improved PFS [hazard ratio (HR): 0.72, 95% CI 0.67-0.77, P < 0.00001]. Furthermore, bevacizumab addition did not significantly improve OS (HR: 0.95, 95% CI 0.87-1.03, P = 0.22). The ORRs in the combination treatment and chemotherapy-alone groups were 42% and 32%, respectively (HR: 1.47, 95% CI 1.26-1.71, P < 0.00001). Bevacizumab addition significantly increased the incidence of therapy discontinuation due to toxicity and toxicity of grade 3 or higher (HR: 1.43, 95% CI 1.06-1.93, P = 0.02, HR: 1.43; 95% CI 1.25-1.64, P < 0.00001, respectively). A qualitative systematic review of two randomized controlled trials indicated no significant differences in quality of life from baseline between the two groups.

CONCLUSIONS

Compared to chemotherapy alone, bevacizumab combined with chemotherapy significantly improved PFS in the HER2-negative MBC patients. However, the lack of a significant OS difference remained.

Comparative Toxicities of Neoadjuvant Chemotherapy With or Without Bevacizumab in HER2-Negative Breast Cancer Patients: A Meta-analysis

Background: The addition of bevacizumab to neoadjuvant chemotherapy improves the pathological complete response rate of human epidermal growth factor 2 (HER2)-negative breast cancer patients. However, the characteristics of adverse events associated with the use of bevacizumab should receive more attention from clinicians. Objective: This meta-analysis aimed to detect the adverse events of adding bevacizumab to neoadjuvant chemotherapy compared with neoadjuvant chemotherapy alone in HER2-negative breast cancer patients. Methods: PubMed, Cochrane Library, Web of Science, and EMBASE databases were systematically accessed to find eligible studies from January 1, 2000, to October 20, 2019. Reference lists were searched for additional studies. Pooled risk ratios for adverse events of bevacizumab were meta-analyzed. Results: Overall, 6 of 829 initially identified studies met the inclusion criteria, with 4681 patients randomized (2321 in the bevacizumab plus neoadjuvant chemotherapy group and 2360 in the neoadjuvant chemotherapy group). The incidence of grade ≥3 hypertension, left-ventricular dysfunction, mucositis, febrile neutropenia, infection, pain, hand-foot syndrome, hemorrhage, and neutropenia significantly increased in patients treated with bevacizumab plus neoadjuvant chemotherapy. However, adding bevacizumab to neoadjuvant chemotherapy was not associated with increasing the incidences of grade ≥3 proteinuria, dyspnea, heart failure, peripheral neurotoxicity, thrombosis, thrombocytopenia, fatigue, leucopenia, vomiting, nausea, and diarrhea. Conclusion and Relevance: Adding bevacizumab to neoadjuvant chemotherapy to treat HER2-negative breast cancer patients increased adverse events. However, most adverse events are clinically manageable. Patients, therefore, need to be monitored carefully for hypertension, left-ventricular dysfunction, mucositis, febrile neutropenia, infection, pain, hand-foot syndrome, hemorrhage, and neutropenia when treated with bevacizumab and neoadjuvant chemotherapy simultaneously.

Comparative Effectiveness of Taxane-Containing Regimens for Treatment of HER2-Negative Metastatic Breast Cancer: A Network Meta-analysis

STUDY OBJECTIVES

To compare the effectiveness of different taxane-containing regimens and to identify the best strategy for the treatment of human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC).

DESIGN

Network meta-analysis of 20 randomized controlled trials (RCTs).

PATIENTS

A total of 6577 patients with HER2-negative MBC who received treatment (20 different regimens) with taxanes (paclitaxel [4267 patients] or docetaxel [2310 patients]).

MEASUREMENTS AND MAIN RESULTS

The PubMed, Embase, Cochrane Library, and ClinicalTrials.gov databases were searched (through March 2019) for RCTs that evaluated any taxane-containing regimens for the treatment of HER2-negative MBC. A network meta-analysis in a Bayesian framework was performed using the random-effects model. We compared the surface under the cumulative ranking (SUCRA) curve for each regimen. Overall, paclitaxel-based combinations were superior to paclitaxel alone in objective response rate (ORR) (odds ratio 1.60, 95% credible interval [CrI] 1.15-2.16) and overall survival (OS) (hazard ratio 1.08, 95% CrI 1.01-1.15). Docetaxel-based combinations were also superior to paclitaxel alone in ORR. Among the paclitaxel-based regimens, based on the results of SUCRA, paclitaxel + bevacizumab + capecitabine was likely to be the most efficacious in improving ORR, OS, and progression-free survival (PFS), whereas paclitaxel + gemcitabine was likely to be the most efficacious in 1-year OS rate. Among the docetaxel-based regimens, based on the results of SUCRA, docetaxel + gemcitabine was likely to be the most efficacious in improving PFS and OS.

CONCLUSION

These findings demonstrated that paclitaxel-based combinations can provide significant improvement in ORR and OS compared with paclitaxel alone. The regimens of paclitaxel + bevacizumab + capecitabine, docetaxel + gemcitabine, and paclitaxel + gemcitabine may be superior to other regimens for the treatment of HER2-negative MBC.

Evaluating the addition of bevacizumab to endocrine therapy as first-line treatment for hormone receptor-positive metastatic breast cancer: a pooled analysis from the LEA (GEICAM/2006-11_GBG51) and CALGB 40503 (Alliance) trials

BACKGROUND

Randomised trials comparing the efficacy of standard endocrine therapy (ET) versus experimental ET + bevacizumab (Bev) in 1st line hormone receptor-positive patients with metastatic breast cancer have thus far shown conflicting results.

PATIENTS AND METHODS

We pooled data from two similar phase III randomised trials of ET ± Bev (LEA and Cancer and Leukemia Group B 40503) to increase precision in estimating treatment effect. Primary end-point was progression-free survival (PFS). Secondary end-points were overall survival (OS), objective response rate (ORR), clinical benefit rate (CBR) and safety. Exploratory analyses were performed within subgroups defined by patients with recurrent disease, de novo disease, prior endocrine sensitivity or resistance and reported grades III-IV hypertension and proteinuria.

RESULTS

The pooled sample consisted of 749 patients randomised to ET or ET + Bev. Median PFS was 14.3 months for ET versus 19 months for ET + Bev (unadjusted hazard ratio [HR] 0.77; 95% confidence interval [CI] 0.66-0.91; p < 0.01). ORR and CBR with ET and ET + Bev were 40 versus 61% (p < 0.01) and 64 versus 77% (p < 0.01), respectively. There was no difference in OS (HR 0.96; 95% CI 0.77-1.18; p = 0.68). PFS was superior for ET + Bev for endocrine-sensitive patients (HR 0.68; 95% CI 0.53-0.89; p = 0.004). Grade III-IV hypertension (2.2 versus 20.1%), proteinuria (0 versus 9.3%), cardiovascular (0.5 versus 4.2%) and liver events (0 versus 2.9%) were significantly higher for ET + Bev (all p < 0.01). Hypertension and proteinuria were not predictors of efficacy (interaction test p = 0.33).

CONCLUSION

The addition of Bev to ET increased PFS overall and in endocrine-sensitive patients but not OS at the expense of significant additional toxicity.

TRIALS REGISTRATION

ClinicalTrial.Gov NCT00545077 and NCT00601900.

Increased risk of adverse drug events secondary to bevacizumab treatment in patients with advanced or metastatic breast cancer: a meta-analysis of randomized controlled trials

Background

Several clinical trials have shown an increased risk of hypertension with bevacizumab when added to chemotherapy in different types of malignancy; however, the risks of other significant adverse events besides hypertension, specifically in breast cancer, have not been completely elucidated. This study was conducted with the aim, primarily, to assess the overall incidence and risk of common toxicities associated with bevacizumab in patients with advanced or metastatic breast cancer and, secondarily, to descriptively review study results concerning a potential correlation between bevacizumab-induced hypertension and its efficacy for breast cancer treatment.

Methods

We carried out a meta-analysis of relevant randomized controlled trials (RCTs) identified from a database search (Cochrane Library and PubMed) and, additionally, by reviewing previous reviews and meta-analyses. Overall incidence rates, odds ratios (ORs), and 95% confidence intervals (CIs) were assessed with the random- or fixed-effect models, depending on the level of heterogeneity across the included trials. The primary clinical outcomes were high-grade adverse events commonly reported with bevacizumab therapy.

Results

We included 6,260 patients with advanced-stage breast cancer from 12 RCTs in the meta-analysis. Five types of high-grade (Grade 3 or 4) adverse drug events were identified as being correlated with bevacizumab treatment versus alternative treatment with statistical significance: hypertension (OR 5.67, 95% CI 3.02–10.65), proteinuria (OR 10.09, 95% CI 4.79–21.27), bleeding (OR 3.45, 95% CI 2.25–5.30), cardiac toxicity (OR 2.15, 95% CI 1.29–3.59), and neutropenic fever (OR 1.51, 95% CI 1.15–2.00). The prognostic value of bevacizumab-induced hypertension for its antitumor efficacy among patients with breast cancer remains controversial, with mixed results presented in the five retrospective studies that were identified from our additional literature search.

Conclusion

The addition of bevacizumab to anticancer therapy was associated with a significant increase in the risk of high-grade adverse events, including hypertension, proteinuria, bleeding, cardiac toxicity, and neutropenic fever among patients with advanced-stage breast cancer. Although several retrospective studies suggested a predictive importance of hypertension secondary to bevacizumab therapy, the role of elevated blood pressure as a prognostic biomarker for its antitumor efficacy remains controversial, and further prospective trials are required to confirm such a correlation.

Bevacizumab significantly increases the risks of hypertension and proteinuria in cancer patients: A systematic review and comprehensive meta-analysis

Published data regarding the overall risks and incidence of hypertension and proteinuria associated with bevacizumab were still unclear. To quantify the precise risks and incidence, we performed this comprehensive meta-analysis of 72 published clinical trials including 21902 cases and 20608 controls. The overall incidence, risk ratios (RRs), and 95% confidence intervals (95% CIs) were calculated using a fixed or random-effect model based on the heterogeneity. The incidence of all-grade and high-grade hypertension were 25.3% (95% CI: 21.5%−29.5%) and 8.2% (95% CI: 7%−9.8%) for patients treated with bevacizumab. And the incidence of all-grade and high-grade proteinuria were 18% (95% CI: 11.7%−26.6%) and 2.4% (95% CI: 1.8%−3.2%), respectively. Compared with controls, bevacizumab significantly increased the risks of all-grade (RR: 3.595, 95% CI: 2.952−4.378) and high-grade hypertension (RR: 5.173, 95% CI: 4.188−6.390). Obviously increased risks of all-grade (RR: 3.369, 95% CI: 2.492−4.556) and high-grade proteinuria (RR: 5.494, 95% CI: 3.991−7.564) were also observed. In the subgroup analysis, the risks of hypertension and proteinuria may significantly vary with bevacizumab dosage, cancer types and concomitant drugs. Whereas, no obvious difference were discovered when stratified based on phase of trials, age of patients, treatment line and duration. So, close monitor and effective management were highly recommended for the safe use of bevacizumab.

Bevacizumab plus paclitaxel versus placebo plus paclitaxel as first-line therapy for HER2-negative metastatic breast cancer (MERiDiAN): A double-blind placebo-controlled randomised phase III trial with prospective biomarker evaluation

AIM

MERiDiAN evaluated plasma vascular endothelial growth factor-A (pVEGF-A) prospectively as a predictive biomarker for bevacizumab efficacy in metastatic breast cancer (mBC).

METHODS

In this double-blind placebo-controlled randomised phase III trial, eligible patients had HER2-negative mBC previously untreated with chemotherapy. pVEGF-A was measured before randomisation to paclitaxel 90 mg/m² on days 1, 8 and 15 with either placebo or bevacizumab 10 mg/kg on days 1 and 15, repeated every 4 weeks until disease progression, unacceptable toxicity or consent withdrawal. Stratification factors were baseline pVEGF-A, prior adjuvant chemotherapy, hormone receptor status and geographic region. Co-primary end-points were investigator-assessed progression-free survival (PFS) in the intent-to-treat and pVEGF-A_high populations.

RESULTS

Of 481 patients randomised (242 placebo-paclitaxel; 239 bevacizumab-paclitaxel), 471 received study treatment. The stratified PFS hazard ratio was 0.68 (99% confidence interval, 0.51-0.91; log-rank p = 0.0007) in the intent-to-treat population (median 8.8 months with placebo-paclitaxel versus 11.0 months with bevacizumab-paclitaxel) and 0.64 (96% confidence interval, 0.47-0.88; log-rank p = 0.0038) in the pVEGF-A_high subgroup. The PFS treatment-by-VEGF-A interaction p value (secondary end-point) was 0.4619. Bevacizumab was associated with increased incidences of bleeding (all grades: 45% versus 27% with placebo), neutropenia (all grades: 39% versus 29%; grade ≥3: 25% versus 13%) and hypertension (all grades: 31% versus 13%; grade ≥3: 11% versus 4%).

CONCLUSION

The significant PFS improvement with bevacizumab is consistent with previous placebo-controlled first-line trials in mBC. Results do not support using baseline pVEGF-A to identify patients benefitting most from bevacizumab.

CLINICAL TRIALS REGISTRATION

ClinicalTrials.gov NCT01663727.

Bevacizumab Addition in Neoadjuvant Treatment Increases the Pathological Complete Response Rates in Patients with HER-2 Negative Breast Cancer Especially Triple Negative Breast Cancer: A Meta-Analysis

Background

Neoadjuvant therapy is administered to breast cancer patients as an induction process before surgery or radiotherapy to reduce tumor size. Human epidermal growth factor receptor-2 (HER-2) negative breast cancer lacks effective standard target therapy. Bevacizumab has a controversial role in the treatment of breast cancer and we conduct a meta-analysis to evaluate the value of adding bevacizumab in neoadjuvant regimen.

Methods

Potentially eligible studies were retrieved using PubMed, EMBASE and Medline. Clinical characteristics of patients and statistical data with pathological complete response (pCR) data were collected. Then a meta-analysis model was established to investigate the correlation between administration of bevacizumab in neoadjuvant therapy and pCR rates in HER-2 negative breast cancer.

Results

Seven eligible studies and 5408 patients were yielded. The pCR rates for “breast” or “breast plus lymph node” were similar. In subgroup analysis, we emphasized on patients with triple-negative breast cancer (TNBC). In the criterion of “lesions in breast” the pooled ORs was 1.55 [1.29, 1.86], P<0.00001 and regarding to the evaluation criterion of “lesions in breast and lymph nodes”, the pooled ORs was 1.48 [1.23, 1.78], P<0.0001, in favor of bevacizumab administration.

Conclusion

According to our pooled results, we finally find that bevacizumab addition as a neoadjuvant chemotherapy component, for induction use with limited cycle to improve the pCR rates and patients may avoid long-term adverse event and long-term invalid survival improvement. Especially in subgroup analysis, pCR rates could be improved significantly and physicians could consider bevacizumab with caution. As patients could avoid the adverse event caused by long-term using of bevacizumab, long-term quality of life improvement may be achieved, especially in TNBC.

Meta-analysis of cardiovascular toxicity risks in cancer patients on selected targeted agents

PURPOSE

The purpose was to estimate the risk and severity of cardiovascular toxicities associated with selected targeted agents.

METHODS

We searched English-language literature for randomized clinical trials published between January 1, 2000 and November 30, 2013 of targeted cancer therapy drugs approved by the FDA by November 2010. One hundred ten studies were eligible. Using meta-analytic methods, we calculated the relative risks of several cardiovascular toxicities [congestive heart failure (CHF), decreased left ventricular ejection fraction (DLVEF), myocardial infarction (MI), arrhythmia, and hypertension (HTN)], adjusting for sample size using the inverse-variance technique. For each targeted agent and side effect, we calculated the number needed to harm.

RESULTS

Regarding CHF, trastuzumab showed significantly greater risk of all-grade and high-grade CHF. There was significant increased risk of all-grade DLVEF with sorafenib, sunitinib, and trastuzumab and high-grade DLVEF with bevacizumab and trastuzumab. Sorafenib was associated with significant increased all-grade risk of MI based on one study. None was associated with high-grade risk of MI or increased risk of arrhythmia. Bevacizumab, sorafenib, and sunitinib had significant increased risk of all-grade and high-grade HTN.

CONCLUSIONS

Several of the targeted agents were significantly associated with increased risk of specific cardiovascular toxicities, CHF, DLVEF, and HTN. Several had significant increased risk for high-grade cardiovascular toxicities (CHF, DLVEF, and HTN). Patients receiving such therapy should be closely monitored for these toxicities and early and aggressive treatment should occur. However, clinical experience has demonstrated that some of these toxicities may be reversible and due to secondary effects.

Efficacy and Safety of Bevacizumab Combined with Chemotherapy for Managing Metastatic Breast Cancer: A Meta-Analysis of Randomized Controlled Trials

Although the FDA revoked metastatic breast cancer (MBC) from bevacizumab (BEV) indication in 2011, BEV combined with paclitaxel has been written in the breast cancer NCCN guidelines. This systematic assessment was performed to evaluate the efficacy and safety of BEV + chemotherapy (CHE) for managing MBC. PubMed and EMBASE were searched for original articles written in English and published before July, 2015. Progression-free survival was significantly improved in the CHE + BEV arms compared to the CHE arms in overall group and in human epidermal growth factor receptor 2-negative group (HR 0.75, 95% CI: 0.68–0.84, P < 0.001; HR 0.75, 95% CI: 0.69–0.82, P < 0.001). There were no significant improvement in overall survival in the CHE + BEV arms compared to the CHE arms. Significantly more grade 3 febrile neutropenia, hypertension, proteinuria, and cardiac events were observed in the CHE + BEV arm, which are controllable and reversible. Severe bleeding occurred more in the BEV + taxane arms and in patients with brain metastases. Therefore, CHE + BEV significantly increases progression-free survival in patients with MBC, it should be considered as a treatment option for these patients under the premise of reasonable selection of target population and combined CHE drugs.

Efficacy and Safety Assessment of the Addition of Bevacizumab to Adjuvant Therapy Agents in Cancer Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

AIM

To evaluate the efficacy and safety of bevacizumab in the adjuvant cancer therapy setting within different subset of patients.

METHODS & DESIGN/ RESULTS

PubMed, EMBASE, Cochrane and Clinical trials.gov databases were searched for English language studies of randomized controlled trials comparing bevacizumab and adjuvant therapy with adjuvant therapy alone published from January 1966 to 7th of May 2014. Progression free survival, overall survival, overall response rate, safety and quality of life were analyzed using random- or fixed-effects models according to the PRISMA guidelines. We obtained data from 44 randomized controlled trials (30,828 patients). Combining bevacizumab with different adjuvant therapies resulted in significant improvement of progression free survival (log hazard ratio, 0.87; 95% confidence interval (CI), 0.84-0.89), overall survival (log hazard ratio, 0.96; 95% CI, 0.94-0.98) and overall response rate (relative risk, 1.46; 95% CI: 1.33-1.59) compared to adjuvant therapy alone in all studied tumor types. In subgroup analyses, there were no interactions of bevacizumab with baseline characteristics on progression free survival and overall survival, while overall response rate was influenced by tumor type and bevacizumab dose (p-value: 0.02). Although bevacizumab use resulted in additional expected adverse drug reactions except anemia and fatigue, it was not associated with a significant decline in quality of life. There was a trend towards a higher risk of several side effects in patients treated by high-dose bevacizumab compared to the low-dose e.g. all grade proteinuria (9.24; 95% CI: 6.60-12.94 vs. 2.64; 95% CI: 1.29-5.40).

CONCLUSIONS

Combining bevacizumab with different adjuvant therapies provides a survival benefit across all major subsets of patients, including by tumor type, type of adjuvant therapy, and duration and dose of bevacizumab therapy. Though bevacizumab was associated with increased risks of some adverse drug reactions such as hypertension and bleeding, anemia and fatigue were improved by the addition of bevacizumab.

A network meta-analysis of everolimus plus exemestane versus chemotherapy in the first- and second-line treatment of estrogen receptor-positive metastatic breast cancer

The goal of this study was to compare the efficacy and toxicity of chemotherapy to exemestane plus everolimus (EXE/EVE) through a network meta-analysis (NMA) of randomized controlled trials. NMA methods extend standard pairwise meta-analysis to allow simultaneous comparison of multiple treatments while maintaining randomization of individual studies. The method enables "direct" evidence (i.e., evidence from studies directly comparing two interventions) and "indirect" evidence (i.e., evidence from studies that do not compare the two interventions directly) to be pooled under the assumption of evidence consistency. We used NMA to evaluate progression-free survival (PFS) and time to progression (TTP) curves in 34 studies, and response rate (RR) and the hazard ratios (HRs) of the PFS/TTP in 36 studies. A number needed to treat (NNT) analysis was also performed as well as descriptive comparison of reported toxicities. The NMA for PFS/TTP curves and for HR shows EXE/EVE is more efficacious than capecitabine plus sunitinib, CMF, megestrol acetate and tamoxifen, with an average of related-PFS/TTP difference ranging from about 10 months for capecitabine plus sunitinib to more than 6 months for tamoxifen. The NMA for overall RR shows that EXE/EVE provides a better RR than bevacizumab plus capecitabine, capecitabine, capecitabine plus sorafenib, capecitabine plus sunitinib, CMF, gemcitabine plus epirubicin plus paclitaxel, EVE plus tamoxifen, EXE, FEC, megestrol acetate, mitoxantrone, and tamoxifen. Finally, the NMA for NNT shows that EXE/EVE is more beneficial as compared to BMF, capecitabine, capecitabine plus sunitinib, CMF, FEC, megestrol acetate, mitoxantrone, and tamoxifen. The combination of EXE/EVE as first- or second-line therapy for ER+ve/HER2-ve metastatic breast cancer is more efficacious than several chemotherapy regimens that were reported in the literature. Toxicities also favored EXE/EVE in most instances.

Motesanib plus carboplatin/paclitaxel in patients with advanced squamous non-small-cell lung cancer: results from the randomized controlled MONET1 study

INTRODUCTION

The phase 3 MONET1 study evaluated motesanib (a small-molecule inhibitor of vascular endothelial growth factor receptors) plus carboplatin/paclitaxel versus placebo plus carboplatin/paclitaxel as first-line therapy for advanced non-small-cell lung cancer (NSCLC). Treatment and enrollment of patients with squamous histology were permanently discontinued following higher early mortality and gross hemoptysis in those with squamous NSCLC who received motesanib. Enrollment of patients with nonsquamous histology was temporarily halted, but resumed following a protocol amendment (Scagliotti et al. J Clin Oncol. 2012;30:2829-2836). Herein, we report data from the squamous cohort.

METHODS

Patients with stage IIIB/IV or recurrent squamous NSCLC (without prior systemic therapy for advanced disease) received up to six 3-week cycles of chemotherapy (carboplatin, area under the curve 6 mg/mL•min/paclitaxel, 200 mg/m) and were randomized 1:1 to receive motesanib 125 mg (Arm A) or placebo (Arm B) once daily. The primary end point was overall survival.

RESULTS

Three-hundred and sixty patients with squamous NSCLC were randomized (Arm A, n = 182; Arm B, n = 178) between July 2007 and November 2008. Twenty-three patients (13%) in Arm A and 10 (6%) in Arm B had fatal adverse events within the first 60 days of treatment. Among these, six patients in Arm A, but none in Arm B, had fatal bleeding events. At final analysis, serious adverse events had occurred in 47% of patients in Arm A and 29% of patients in Arm B. Median overall survival was similar in Arms A and B (11.1 versus 10.7 months).

CONCLUSIONS

Motesanib plus carboplatin/paclitaxel had unacceptable toxicity compared with carboplatin/paclitaxel alone in patients with advanced squamous NSCLC.

Republished: Importance of carcinoma-associated fibroblast-derived proteins in clinical oncology

Carcinoma-associated fibroblast (CAF) as prominent cell type of the tumour microenvironment has complex interaction with both the cancer cells and other non-neoplastic surrounding cells. The CAF-derived regulators and extracellular matrix proteins can support cancer progression by providing a protective microenvironment for the cancer cells via reduction of chemotherapy sensitivity. On the other hand, these proteins may act as powerful prognostic markers as well as potential targets of anticancer therapy. In this review, we summarise the clinical importance of the major CAF-derived signals influencing tumour behaviour and determining the outcome of chemotherapy.

Motesanib with or without panitumumab plus FOLFIRI or FOLFOX for the treatment of metastatic colorectal cancer

PURPOSE

This study assessed the safety, efficacy, and pharmacokinetics of motesanib, a multitargeted small molecule angiogenesis inhibitor, with and without panitumumab, in combination with FOLFIRI or FOLFOX in patients with metastatic colorectal cancer (mCRC).

METHODS

This open-label, phase 1b, two-part, multicenter study in patients with mCRC and ≤1 prior treatment evaluated escalating doses (50, 75, 100, or 125 mg QD, 75 mg BID) of motesanib with panitumumab and chemotherapy (Part 1) and the target dose of motesanib with chemotherapy (Part 2).

RESULTS

At 17 sites in the USA and Australia, 119 patients were enrolled between December 2004 and February 2010. In Part 1 [motesanib plus panitumumab/FOLFIRI (n = 36) or plus panitumumab/FOLFOX (n = 17)], all motesanib doses tested were tolerated and 125 mg QD was deemed the target dose. Following toxicity results for combination therapy in other trials, panitumumab was withdrawn from the study. Part 2 evaluated motesanib 125 mg with chemotherapy [FOLFIRI (n = 37); FOLFOX (n = 29)]. The primary endpoint, objective response rate in patients with measurable disease by RECIST, was 20 % overall and was higher among patients receiving first-line (27 % overall; FOLFOX, 24 %; FOLFIRI, 27 %) compared with second-line therapy (14 % overall; FOLFOX, 0 %; FOLFIRI, 20 %). The most common adverse events were diarrhea, nausea, fatigue, and hypertension. We observed a low rate of cholecystitis [3 of 119 (2.5 %)], a known adverse event of motesanib and other small molecule VEGF inhibitors.

CONCLUSIONS

Motesanib 125 mg QD in combination with FOLFIRI or FOLFOX chemotherapy was tolerated and demonstrated modest efficacy in first-/second-line mCRC.

Receptor tyrosine kinase inhibitors: Are they real tumor killers?

Inhibiting tumor growth by targeting the tumor vasculature was first proposed by Judah Folkman almost 40 years ago. Since then, different approaches and numerous drugs and agents have been developed to achieve this goal, either with the aim of inhibiting tumor neoangiogenesis or normalizing the tumor vasculature. Among the most promising therapeutic targets are receptor tyrosine kinases (RTKs), some of which are predominantly expressed on tumor endothelial cells, although they are sometimes also present on tumor cells. The majority of RTK inhibitors investigated over the past two decades competes with ATP at the active site of the kinase and therefore block the phosphorylation of intracellular targets. Some of these drugs have been approved for therapy, whereas others are still in clinical trials. Here, we discuss the scientific basis, current status, problems and future prospects of RTK inhibition in anti-tumor therapy.

Trebananib (AMG 386) plus weekly paclitaxel with or without bevacizumab as first-line therapy for HER2-negative locally recurrent or metastatic breast cancer: A phase 2 randomized study

INTRODUCTION

This phase 2 randomized study evaluated trebananib (AMG 386), a peptide-Fc fusion protein that inhibits angiogenesis by neutralizing the interaction of angiopoietin-1 and -2 with Tie2, in combination with paclitaxel with or without bevacizumab in previously untreated patients with HER2-negative locally recurrent/metastatic breast cancer.

METHODS

Patients received paclitaxel 90 mg/m(2) once weekly (3-weeks-on/1-week-off) and were randomly assigned 1:1:1:1 to also receive blinded bevacizumab 10 mg/kg once every 2 weeks plus either trebananib 10 mg/kg once weekly (Arm A) or 3 mg/kg once weekly (Arm B), or placebo (Arm C); or open-label trebananib 10 mg/kg once a week (Arm D). Progression-free survival was the primary endpoint.

RESULTS

In total, 228 patients were randomized. Median estimated progression-free survival for Arms A, B, C, and D was 11.3, 9.2, 12.2, and 10 months, respectively. Hazard ratios (95% CI) for Arms A, B, and D versus Arm C were 0.98 (0.61-1.59), 1.12 (0.70-1.80), and 1.28 (0.79-2.09), respectively. The objective response rate was 71% in Arm A, 51% in Arm B, 60% in Arm C, and 46% in Arm D. The incidence of grade 3/4/5 adverse events was 71/9/4%, 61/14/5%, 62/16/3%, and 52/4/7% in Arms A/B/C/D. In Arm D, median progression-free survival was 12.8 and 7.4 months for those with high and low trebananib exposure (AUCss ≥ 8.4 versus < 8.4 mg·h/mL), respectively.

CONCLUSIONS

There was no apparent prolongation of estimated progression-free survival with the addition of trebananib to paclitaxel and bevacizumab at the doses tested. Toxicity was manageable. Exposure-response analyses support evaluation of combinations incorporating trebananib at doses > 10 mg/kg in this setting.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00511459.

Paclitaxel and bevacizumab with or without capecitabine as first-line treatment for HER2-negative locally recurrent or metastatic breast cancer: a multicentre, open-label, randomised phase 2 trial

BACKGROUND

The addition of bevacizumab to paclitaxel or capecitabine has demonstrated improved progression-free survival (PFS) and objective response rate (ORR) as compared with chemotherapy alone in patients with HER2-negative locally recurrent or metastatic breast cancer (LR/MBC). We evaluated the efficacy and safety of first-line therapy of paclitaxel and bevacizumab with or without capecitabine in patients with HER2-negative LR/MBC.

METHODS

In this multicentre, open-label, randomised phase II trial, women with HER2-negative LR/MBC were randomly assigned in a 1:1 ratio to paclitaxel (90 mg/m2 intravenously [IV] on days 1, 8, and 15) and bevacizumab (10 mg/kg IV on days 1 and 15) every 4 weeks for six cycles, followed by bevacizumab (15 mg/kg IV on day 1) every 3 weeks (AT) or to paclitaxel (90 mg/m2 IV on days 1 and 8), bevacizumab (15 mg/kg IV on day 1) and capecitabine (825 mg/m2 orally twice daily on days 1–14) every 3 weeks for eight cycles, followed by bevacizumab and capecitabine at the same doses every 3 weeks (ATX). The primary end-point was investigator-assessed PFS. Secondary end-points included ORR, duration of response, overall survival (OS) and safety. Exploratory analyses were conducted to evaluate the impact of capecitabine on OS and to validate a novel prognostic model. This trial is registered with EudraCT, number 2006-006058-83.

FINDINGS

Median PFS was significantly longer in ATX as compared with AT (11.2 months versus 8.4 months; stratified hazard ratio (HR), 0.52; 95% confidence interval (CI), 0.41–0.67; p < 0.0001). The ORR in ATX patients with measurable disease (n = 268) was higher than that in AT (69% versus 51%; p = 0.01). The median duration of response was 6.8 versus 5.4 months for, respectively, ATX and AT (p < 0.0001). Median OS was 24.2 months for ATX and 23.1 months for AT (p = 0.53). The increased rate of grade 3–4 adverse events related to the addition of capecitabine, being hand-foot syndrome (34% versus 0% for AT) and neutropenia (20% versus 12% for AT), generally did not preclude continuation of treatment. Exploratory analyses indicated that (1) patients receiving capecitabine at some line for treatment have significantly improved OS and (2) a prognostic model can classify patients into three risk groups associated with OS.

INTERPRETATION

In patients with HER2-negative LR/MBC, addition of capecitabine to paclitaxel and bevacizumab significantly improved PFS, ORR and response duration. This combination was reasonably well tolerated and may be considered of use as first-line treatment in rapidly progressive disease.

FUNDING

F. Hoffmann-La Roche Ltd, the Netherlands.

Novel antiangiogenic drugs for the management of breast cancer: new approaches for an old issue?

Since angiogenesis plays an important role in cancer growth, infiltration and metastasis, many agents targeting this pathway have been developed over the last decade. Antiangiogenic drugs interfere with this process and may inhibit neoplastic growth or induce tumor dormancy by blocking the expanding network of newly formed capillaries. Despite the initial promise, targeting angiogenesis in breast cancer has not reached major breakthroughs. Nevertheless, the immunologic role of VEGF deserves to be further explored. We aim to describe the biological mechanisms which underlie the role of angiogenesis in breast cancer carcinogenesis, to depict its contribution to the metastatic process and to review the most important clinical trials testing angiogenic inhibitors in breast cancer, including monoclonal antibodies and novel small molecules.

Importance of carcinoma-associated fibroblast-derived proteins in clinical oncology

Carcinoma-associated fibroblast (CAF) as prominent cell type of the tumour microenvironment has complex interaction with both the cancer cells and other non-neoplastic surrounding cells. The CAF-derived regulators and extracellular matrix proteins can support cancer progression by providing a protective microenvironment for the cancer cells via reduction of chemotherapy sensitivity. On the other hand, these proteins may act as powerful prognostic markers as well as potential targets of anticancer therapy. In this review, we summarise the clinical importance of the major CAF-derived signals influencing tumour behaviour and determining the outcome of chemotherapy.

Multitarget inhibitors derived from crosstalk mechanism involving VEGFR2

Seven VEGFR small-molecule inhibitors have been approved by the US FDA as anticancer drugs, which confirms the therapeutic value of angiogenesis inhibitors. However, much more evidence indicates that VEGFR inhibition alone is usually not sufficient to block the tumor progress. The potential of some agents targeting VEGFR owes partially to the simultaneous inhibition of additional targets in other signaling pathways. In this review, the crosstalk between VEGFR2 and the additional targets in other signaling pathways, such as EGFR, MET, FGFR, PDGFR, c-Kit, Raf, PI3K and HDAC, and the synergistic effects derived from multitarget activities against these crosstalks are discussed. We also briefly describe the multitarget inhibitors in clinical trials or reported in the literature and patents under the different multitarget categories involving VEGFR2.

Newer therapies for the treatment of metastatic breast cancer: a clinical update

Breast cancer is the foremost common malignancy among the female population around the world. Female breast cancer incidence rates have increased since 1980, slowed in 1990, the rate of increase have leveled off since 2001. In spite of the advances in the early detection, treatment, surgery and radiation support, almost 70% of the patients develop metastasis and die of the disease. Around 10% of the patients when diagnosed with breast cancer have metastases. Survival among the breast cancer patients have increased due to the introduction of novel single agent, combination of chemotherapeutic agents and targeted biologic agents, which is breast cancer specific. The staging of tumor-node-metastasis is significant for the prognosis and treatment. Predominantly the combination of chemotherapeutic regimen is given to improve the rate of clinical benefit and the overall survival rate. Novel mono-therapeutic options are being used often in metastatic setting as they will not be able to endure the toxicity of the combination regimen. Usually, endocrine therapy is recommended for hormone-responsive breast cancer due to efficacy and favorable side effect profile but chemotherapy becomes an option when endocrine therapy fails. This review summarizes the newer therapeutic options for early breast cancer and advanced breast cancer that are pretreated heavily on other chemotherapeutic agents. Further it provides monotherapies and other emerging novel combination regime which can be opted for first line or second line setting.

A systematic review of bevacizumab efficacy in breast cancer

Angiogenesis is a key component of cancer growth, invasion and metastasis. Therefore, inhibition of angiogenesis is an attractive strategy for the treatment of cancer. We systematically describe phase II and III clinical trials of bevacizumab for the treatment of breast cancer.

METHODS

A computer-based literature search was carried out using PUBMED and conference databases. Original phase II and III studies reporting ≥15 patients who received bevacizumab were included.

RESULTS

41 phase II trials were identified in the metastatic setting. Most trials found bevacizumab treatment feasible. Response rates (RR) varied from 0% to 76.5%, time to progression (TTP)/progression free survival (PFS) from 2.4 to 25.3 months and overall survival from 11.5 to more than 38 months. 14 phase III trials including more than 4400 patients with MBC unanimously showed increased RR and PFS, however, no trials demonstrated an OS benefit. In the neoadjuvant setting 23 phase II and III trials were identified. All studies found increased pCR/tpCR but no benefit in terms of OS could be demonstrated. The only study conducted in the adjuvant setting failed to show any survival benefit of bevacizumab.

CONCLUSION

Despite increased response rates in both the metastatic and neoadjuvant setting, bevacizumab has failed to show any OS benefit. Future trials should include identification of robust predictive biomarkers in order to improve our understanding of molecular biomarkers and mechanisms.

An updated meta-analysis of fatal adverse events caused by bevacizumab therapy in cancer patients

Background

The risk of fatal adverse events (FAEs) due to bevacizumab-based chemotherapy has not been well described; we carried out an updated meta-analysis regarding this issue.

Methods

An electronic search of Medline, Embase and The Cochrane Central Register of Controlled Trials was conducted to investigate the effects of randomized controlled trials on bevacizumab treatment on cancer patients. Random or fixed-effect meta-analytical models were used to evaluate the risk ratio (RR) of FAEs due to the use of bevacizumab.

Results

Thirty-four trials were included. Allocation to bevacizumab therapy significantly increased the risk of FAEs; the RR was 1.29 (95% CI:1.05–1.57). This association varied significantly with tumor types (P = 0.002) and chemotherapeutic agents (P = 0.005) but not with bevacizumab dose (P = 0.90). Increased risk was seen in patients with non–small cell lung cancer, pancreatic cancer, prostate cancer, and ovarian cancer. However, FAEs were lower in breast cancer patients treated with bevacizumab. In addition, bevacizumab was associated with an increased risk of FAEs in patients who received concomitant agents of taxanes and/or platinum.

Conclusion

Compared with chemotherapy alone, the addition of bevacizumab was associated with an increased risk of FAEs among patients with special tumor types, particularly when combined with chemotherapeutic agents such as platinum.

The efficacy of bevacizumab plus paclitaxel as first-line treatment for HER2-negative metastatic breast cancer: a meta-analysis of randomized controlled trials

Although both bevacizumab and paclitaxel significantly improve the efficacy of chemotherapy for human epidermal growth factor receptor 2 (HER2)-negative patients with metastatic breast cancer (MBC), little have changed with overall survival rates when they have been used alone or combined with other chemotherapy. Thus, a meta-analysis was conducted to evaluate the efficacy of bevacizumab combined with paclitaxel in HER2-negative MBC patients. Pubmed and Embase were systematically reviewed for studies published up to September 2013 in which bevacizumab plus paclitaxel were compared with other chemotherapy. Primary outcomes comprised overall survival (OS), progression-free survival (PFS), and objective response rate (ORR). Eight phase II/III clinical trials met the inclusion criteria, with a total of 3,758 patients. The pooled results showed that combination of bevacizumab and paclitaxel significantly improved the PFS (HR = 0.63, 95% CI, 0.55-0.73, P = 0.011), ORR (RR = 1.28, 95% CI, 0.96-1.70, P = 0.0), but had no effect on OS (HR = 0.91, 95% CI, 0.81-1.01, P = 0.855). The meta-analysis confirms the benefits of bevacizumab-paclitaxel combination therapy in HER2 negative metastatic breast cancer, with an improvement in both progression free survival and objective response rate. However, no significant OS benefit was observed.

Multitargeted antiangiogenic tyrosine kinase inhibitors combined to chemotherapy in metastatic breast cancer: a systematic review and meta-analysis

PURPOSE

We undertook a meta-analysis of randomized trials to evaluate the efficacy of multitargeted antiangiogenic tyrosine kinase inhibitors (MATKIs) in addition to chemotherapy in metastatic breast cancer.

METHODS

PubMed, Web of Knowledge databases and the ASCO meeting abstracts were searched for eligible literature published up to August 30, 2013. The endpoints included progression-free survival (PFS), overall survival (OS), overall response rate (ORR) and toxicities. Pooled hazard ratios (HRs) for survival outcomes and odds ratio (ORs) for dichotomous data with 95 % confidence intervals (CIs) were derived.

RESULTS

Eight studies including 2,077 participants were analyzed. Compared to chemotherapy alone, adding MATKIs to chemotherapy resulted in a 14 % risk reduction of PFS events. However, the benefit did not reach statistical significance (HR 0.86; 95 % CI 0.70-1.04, P=0.126). Also, no OS benefit was observed (HR 1.03; 95 % CI 0.89-1.18, P=0.724). The addition of MATKIs significantly increased the ORR (OR 1.57; 95 % CI 1.30-1.91, P=0.000). Subgroup analysis revealed that sorafinib showed a significantly greater effect on PFS in patients with HER2 negative metastatic breast cancer (HR 0.67; 95 % CI 0.55-0.82, P=0.000) in comparison to chemotherapy alone. Additionally, sunitinib seemed to have no substantial efficacy for metastatic breast cancer. Toxicities were more frequent in patients receiving MATKIs.

CONCLUSION

Overall, regimens consisting of MATKIs seemed not to be superior to chemotherapy alone in terms of PFS and OS, although significant improvement in ORR was observed. However, the addition of sorafenib significantly improved PFS. Further studies are needed to corroborate this finding.

First-line bevacizumab in combination with chemotherapy for HER2-negative metastatic breast cancer: pooled and subgroup analyses of data from 2447 patients

BACKGROUND

Bevacizumab has consistently demonstrated improved progression-free survival (PFS) and response rate when combined with first-line chemotherapy for HER2-negative metastatic breast cancer (mBC). However, the lack of a significant overall survival (OS) difference continues to attract debate, and identification of patients deriving greatest benefit from bevacizumab remains elusive.

PATIENTS AND METHODS

Individual patient data from three randomised phase III trials in the first-line HER2-negative mBC setting were analysed, focusing specifically on efficacy in poor-prognosis patients.

RESULTS

The meta-analysis (n = 2447) demonstrated a PFS hazard ratio (HR) of 0.64 (95% confidence interval [CI] 0.57-0.71; median 9.2 months with bevacizumab versus 6.7 months with non-bevacizumab therapy) and response rate of 49% versus 32%, respectively. The OS HR was 0.97 (95% CI 0.86-1.08); median 26.7 versus 26.4 months, respectively. In patients with triple-negative mBC, the HRs for PFS and OS were 0.63 (95% CI 0.52-0.76) and 0.96 (95% CI 0.79-1.16), respectively. Median PFS was 8.1 months with bevacizumab versus 5.4 months with chemotherapy alone, median OS was 18.9 versus 17.5 months, respectively, and 1-year OS rates were 71% versus 65%.

CONCLUSIONS

Bevacizumab improves efficacy, including 1-year OS rates, both overall and in subgroups of poor-prognosis patients with limited treatment options.

Molecular-targeted agents combination therapy for cancer: developments and potentials

Although chemotherapy has advanced into the era of targeted drugs, the antitumor efficacies of current therapies are limited, most likely because of the high degree of cancer clonal heterogeneity, intratumor genetic heterogeneity and cell signal complexity. As shutdown of a single target does not necessarily eradicate the cancer, the use of combinations of molecular-targeted agents (MATs) has been proposed, and some pioneering research has been conducted to examine the efficacy of this strategy. In this article, the clinical and preclinical studies that are underway in an attempt to improve the anticancer efficacy of chemotherapies through combination strategies are summarized. Studies of combining cytotoxic agents with MATs, coinhibiting two or more targets in a single pathway or coinhibiting parallel or compensatory pathways as well as specific combinations will be introduced, and the antitumor potentials of each combination strategy will be evaluated.

A randomized, phase II, three-arm study of two schedules of ixabepilone or paclitaxel plus bevacizumab as first-line therapy for metastatic breast cancer

The aim of this phase II trial was to estimate the objective response rate (ORR) of two different schedules of ixabepilone [weekly or every 3 weeks (Q3W)] combined with bevacizumab, relative to a reference arm of weekly paclitaxel and bevacizumab. Patients with human epidermal growth factor receptor 2-normal, chemotherapy-naïve metastatic breast cancer (MBC) were randomized 3:3:2 to ixabepilone 16 mg/m(2) weekly plus bevacizumab 10 mg/kg Q2W (Arm A: n = 46); ixabepilone 40 mg/m(2) Q3W (reduced to 32 mg/m(2) after four cycles of treatment) plus bevacizumab 15 mg/kg Q3W (Arm B: n = 45); or paclitaxel 90 mg/m(2) weekly plus bevacizumab 10 mg/kg intravenous infusion Q2W (Arm C: n = 32). Of 123 randomized patients, 122 were treated. All were followed for ≥19 months; 5 % of patients remained on study treatment at the time of this analysis. Grade 3 or 4 neutropenia was more common in Arm B (60 %) than Arms A (16 %) or C (22 %); other adverse events were similar. The investigator-assessed ORR was 48, 71, and 63 % for Arms A, B, and C, respectively. Median progression-free survival (randomized patients) was 9.6 months in Arm A, 11.9 months in Arm B, and 13.5 months in Arm C. In conclusion, ixabepilone Q3W plus bevacizumab has clinical activity as first-line therapy for MBC relative to paclitaxel plus bevacizumab, but with significantly greater risk of grade 3 or 4 neutropenia. In addition, these data suggest that weekly dosing of ixabepilone may be less active than Q3W dosing, but with less neutropenia.

The potential role of aerobic exercise to modulate cardiotoxicity of molecularly targeted cancer therapeutics

Molecularly targeted therapeutics (MTT) are the future of cancer systemic therapy. They have already moved from palliative therapy for advanced solid malignancies into the setting of curative-intent treatment for early-stage disease. Cardiotoxicity is a frequent and potentially serious adverse complication of some targeted therapies, leading to a broad range of potentially life-threatening complications, therapy discontinuation, and poor quality of life. Low-cost pleiotropic interventions are therefore urgently required to effectively prevent and/or treat MTT-induced cardiotoxicity. Aerobic exercise therapy has the unique capacity to modulate, without toxicity, multiple gene expression pathways in several organ systems, including a plethora of cardiac-specific molecular and cell-signaling pathways implicated in MTT-induced cardiac toxicity. In this review, we examine the molecular signaling of antiangiogenic and HER2-directed therapies that may underpin cardiac toxicity and the hypothesized molecular mechanisms underlying the cardioprotective properties of aerobic exercise. It is hoped that this knowledge can be used to maximize the benefits of small molecule inhibitors, while minimizing cardiac damage in patients with solid malignancies.

New developments and future directions in systemic therapy

Adjuvant systemic therapies for breast cancer have led to a significant reduction in the risk of relapse and improvement in overall survival. However, a substantial proportion of breast cancer patients still ultimately experience relapse with metastatic disease. Here we review recent progress in trials of systemic therapies, including endocrine therapy, chemotherapy and targeted therapies for breast cancer. A current challenge for translational research is to identify drivers of resistance that may be amenable to therapy, as well as potential compensatory mechanisms that might limit the effectiveness of novel therapies. Unfortunately, not all targeted agents entering clinical trials will show sufficient efficacy to be approved for use. We highlight key findings from trials of novel agents, and the need for further research to identify biomarkers of response to systemic therapies in breast cancer.

Strategies for improving the clinical benefit of antiangiogenic drug based therapies for breast cancer

Viewed as a whole, the aggregate outcomes of a number of positive randomized phase III clinical trial results evaluating the VEGF-pathway targeting antiangiogenic drug bevacizumab, with or without concurrent chemotherapy, in metastatic breast cancer patients have been disappointingly modest. In the case of antiangiogenic tyrosine kinase inhibitors (TKIs) the results have been negative. Nevertheless, several findings indicate antiangiogenic drugs, especially bevacizumab, are active and can lead to demonstrable clinical benefit in some patients, thus stimulating research into developing strategies to significantly improve their efficacy and reduce toxicity. Some of these initiatives include: 1) discovery and validation of predictive markers that can prospectively identify patients more likely to benefit from antiangiogenic therapy; 2) recognition that the nature of the chemotherapy partner or backbone can strongly impact outcomes when combined with antiangiogenic drugs such as bevacizumab, and thus developing what may be improved combination chemotherapy partner regimens, e.g. metronomic chemotherapy; 3) evaluating prospectively in more depth whether subtypes of the disease-especially triple negative or inflammatory breast cancer-are more responsive to antiangiogenic therapy than other subtypes; 4) evaluating new agents that inhibit angiogenesis in a VEGF-independent manner and other types of drug that can be effectively combined with antiangiogenics, e.g. c-met inhibitors; 5) uncovering the basis of resistance or relapse/progression on the therapy with antiangiogenic drugs; 6) development of improved predictive preclinical breast cancer models for therapy testing, e.g. treatment of mice with established multi-organ breast cancer metastatic disease or genetically engineered mouse models of breast cancer, or mice bearing patient derived breast cancer tissue xenografts.

Patients with metastatic breast cancer using bevacizumab as a treatment: is there still a role for it?

OPINION STATEMENT

Over the last few decades, the angiogenesis mechanism has increasingly been studied and implicated in cancer pathophysiology. At present, it is known that angiogenesis plays a relevant role in tumor growth, and more importantly many new molecules exists can potentially interfere with this process. Bevacizumab, a humanized monoclonal antibody targeting the vascular endothelial growth factor A (VEGF-A) now commonly used in the treatment of colorectal, renal cell, and brain cancer, is the first anti-angiogenesis drug delivered in combination with chemotherapy that has consistently shown clinical efficacy in the treatment of breast cancer. Since the ECOG 2100 trial has shown that bevacizumab added to paclitaxel as a first-line treatment for advanced breast cancer nearly doubled the time to progression and tumor response rate, its approval was granted almost worldwide. However, other phase III trials revealed a smaller absolute improvement in progression-free survival (PFS) and response rates, and no trials yet have demonstrated survival enhancement which led to a great controversy and debate over the use of bevacizumab. The discrepancy between PFS and overall survival also raises the question of whether or not bevacizumab has been applied sub-optimally in some of the studies, if a predictive biomarker(s) exists to select the group of patients whom would receive the greatest benefit and what is the appropriate clinical end-point for approval and funding of new targeted agents. In this article we will review the bevacizumab mechanism of action and the clinical trials that assessed its benefit in the treatment of metastatic breast cancer (MBC).

Novel targeted agents for the treatment of advanced breast cancer

The discovery of the molecular processes involved in cancer development has led to the design of an array of targeted agents. These agents, directed to specific proteins in the machinery of cancer cells, interfere with vital cascades involved in cell invasion, metastasis, apoptosis, cell-cycle control and angiogenesis. In breast cancer, the main pathways studied and targeted by drugs are the HER2 pathway, EGFR, VEGF, PI3K/Akt/mammalian target of rapamycin (PI3K-M-Tor), IGF/IGFR, poly(ADP ribose) polymerase 1, HDAC and many others. In this review, we present the most promising studies of these new targeted therapies and novel combination of targeted therapies with cytotoxic agents for the treatment of breast cancer patients.

Phase 1b dose-finding study of motesanib with docetaxel or paclitaxel in patients with metastatic breast cancer

The purpose of this study was to investigate the safety, tolerability, and pharmacokinetics of motesanib when combined with docetaxel or paclitaxel in patients with metastatic breast cancer. In this open-label, dose-finding, phase 1b study, patients received motesanib 50 or 125-mg orally once daily (QD), beginning day 3 of cycle 1 of chemotherapy, continuously in combination with either paclitaxel 90 mg/m² on days 1, 8, and 15 every 28-day cycle (Arm A) or docetaxel 100 mg/m² on day 1 every 21-day cycle (Arm B). Dose escalation to motesanib 125 mg QD occurred if the incidence of dose-limiting toxicities (DLTs, primary endpoint) was ≤33 %. If the maximum tolerated dose (MTD) of motesanib was established in Arm B, additional patients could receive motesanib at the MTD plus docetaxel 75 mg/m². Forty-six patients were enrolled and 45 received ≥1 dose of motesanib. The incidence of DLTs was <33 % in all cohorts; thus, motesanib 125 mg QD was established as the MTD. Seven patients (16 %) had grade 3 motesanib-related adverse events including cholecystitis (2 patients) and hypertension (2 patients). Pharmacokinetic parameters of motesanib were similar to those reported in previous studies. The objective response rate was 56 % among patients with measurable disease at baseline who received motesanib in combination with taxane-based chemotherapy. The addition of motesanib to either paclitaxel or docetaxel was generally tolerable up to the 125-mg QD dose of motesanib. The objective response rate of 56 % suggests a potential benefit of motesanib in combination with taxane-based chemotherapy.