Paclitaxel, bevacizumab, and everolimus/placebo as first-line treatment for patients with metastatic HER2-negative breast cancer: a randomized placebo-controlled phase II trial of the Sarah Cannon Research Institute

Evaluating everolimus for the treatment of breast cancer

INTRODUCTION

Everolimus is an oral drug that inhibits mTOR with immunosuppressive and antiproliferative characteristics. It is commonly used in association with exemestane in hormone receptor (HR)-positive advanced breast cancer (ABC).

AREAS COVERED

The current review summarizes the publications relating to everolimus from clinical research in breast cancer. Everolimus showed treatment efficacy and an acceptable safety tolerance with prevention of side effects in Phase II/III studies. BOLERO-2 study showed a progression-free survival improvement in patients with HR-positive ABC previously treated with aromatase inhibitors (AI) and leading to its acceptance in this indication. The absence of a post CDK4/6 inhibitor (CDK4/6i.) study and the arrival of new drugs may raise questions about its current place in the therapeutic strategy.

EXPERT OPINION

Everolimus is relevant in the management of HR-positive ABC. Because of its efficacy, acceptable tolerability and the absence of drugs that have shown a greater benefit, it remains a second-line treatment option in HR-positive, HER2 negative (score 0) patients without BRCA mutation or visceral crisis and can be discuss with fulvestrant in second line after CDK4-6i. It is likely that within 5 years this treatment will be replaced in second line HR-positive breast cancer by new emerging treatments: drug-conjugated antibodies, tyrosine kinase inhibitors or immunotherapy in combination with chemotherapy.

Patient preferences for breast cancer treatments: a discrete choice experiment in France, Ireland, Poland, Spain

Aim: To understand breast cancer patients' trade-offs when choosing treatments and to identify the most important treatment attributes which drive decisions. Materials & methods: A discrete choice experiment was conducted in France, Ireland, Poland and Spain. Progression-free survival, febrile neutropenia, pain, functional well-being and out-of-pocket payment were the treatment attributes. Results: 371 patients were willing to pay €6896 per year for 1 additional year of progression-free survival, €17,288 per year for perfect functional well-being and €15,138 for one pain-free year. Patients are willing to trade off progression-free survival months for better functional abilities and less pain. Conclusion: Patient preferences should be considered by regulatory agencies, reimbursement bodies, payors and clinicians for best treatment choices for the individuals.

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.

Molecular subtypes and precision treatment of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype. Despite the progress made in precision treatment of cancer patients, targeted treatment is still at its early stage in TNBC, and chemotherapy remains the standard treatment. With the advances in next generation sequencing technology, genomic and transcriptomic analyses have provided deeper insight into the inter-tumoral heterogeneity of TNBC. Much effort has been made to classify TNBCs into different molecular subtypes according to genetic aberrations and expression signatures and to uncover novel treatment targets. In this review, we summarized the current knowledge regarding the molecular classification of TNBC and explore the future paradigm for using molecular classification to guide the development of precision treatment and clinical practice.

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.

Targeting PI3K/Akt/mTOR signaling pathway by polyphenols: Implication for cancer therapy

Cancer is one of the biggest challenges facing medicine and its cure is regarded to be the Holy Grail of medicine. Therapy in cancer is consisted as various artificial cytotoxic agents and radiotherapy, and recently immunotherapy. Recently much attention has been directed to the use of natural occurring agents in cancer therapy. One of the main group of agents utilized in this regard is polyphenols which are found abundantly in berries, fruits and vegetables. Polyphenols show to exert direct and indirect effects in progression of cancer, angiogenesis, proliferation and enhancing resistance to treatment. One of the cellular pathways commonly affected by polyphenols is PI3K/Akt/mTOR pathway, which has far ranging effects on multiple key aspects of cellular growth, metabolism and death. In this review article, evidence regarding the biology of polyphenols in cancer via PI3K/Akt/mTOR pathway is discussed and their application on cancer pathophysiology in various types of human malignancies is shown.

Renal toxicity with mammalian target of rapamycin inhibitors: A meta-analysis of randomized clinical trials

A meta-analysis of randomized clinical trials (RCT) was done to determine the relative risk (RR) of acute kidney injury (AKI) with the use of mammalian target of rapamycin (mTOR) inhibitors. Citations from PubMed/Medline, clinical trials.gov, package inserts and abstracts from major conferences were reviewed to include RCTs comparing arms with or without mTOR inhibitors. The RR of all grade AKI in patients taking mTOR inhibitors compared to patients not on mTOR inhibitors was 1.55 (95% CI: 1.11 to 2.16, P=0.010). There was no significant difference in the risk of high-grade AKI for the two groups (RR=1.29, P=0.118, 95% CI: 0.94 to 1.77). There was no significant difference in the incidence rates for either all grade or high-grade AKI between the two groups. There was no publication bias and the trials were of high quality per Jadad scoring.

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.

Everolimus-based combination therapies for HR+, HER2- metastatic breast cancer

Metastatic breast cancer (MBC) is the leading cause of cancer-related morbidity and mortality among women worldwide. Endocrine therapy is the standard of care for the most common subtype of MBC, hormone-receptor positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) disease. Advances in treating this type of MBC have focused on improving the efficacy of endocrine therapy by adding agents that target specific molecular pathways of breast cancer cell growth and survival. The combination of the aromatase inhibitor exemestane and the mammalian target of rapamycin inhibitor, everolimus, more than doubled median progression-free survival compared with exemestane alone (7.8 vs 3.2 months, respectively; hazard ratio 0.45 [95% confidence interval 0.38-0.54]; log rank P < 0.0001) in the BOLERO-2 study in postmenopausal women with HR+, HER2- locally advanced or metastatic breast cancer that had recurred or progressed on prior non-steroidal aromatase inhibitor therapy. In addition, everolimus plus exemestane was associated with a manageable safety profile. The results of BOLERO-2 led to regulatory approval of everolimus plus exemestane. Additional everolimus-based combinations have been or are under investigation in the HR+, HER2- MBC setting, including combinations with letrozole, fulvestrant, ribociclib, tamoxifen, and chemotherapy. This review summarizes key data on everolimus-based combinations focusing on efficacy, safety, biomarkers, quality of life, and health economic outcomes. These data are discussed in the context of the changing MBC treatment algorithm to provide insights into the clinical relevance of everolimus-based combinations.

mTOR signalling: jack-of-all-trades 1

The mechanistic target of rapamycin (mTOR) is an evolutionarily conserved serine/threonine kinase that senses and integrates environmental information into cellular regulation and homeostasis. Accumulating evidence has suggested a master role of mTOR signalling in many fundamental aspects of cell biology and organismal development. mTOR deregulation is implicated in a broad range of pathological conditions, including diabetes, cancer, neurodegenerative diseases, myopathies, inflammatory, infectious, and autoimmune conditions. Here, we review recent advances in our knowledge of mTOR signalling in mammalian physiology. We also discuss the impact of mTOR alteration in human diseases and how targeting mTOR function can treat human diseases.

Efficacy of PI3K/AKT/mTOR pathway inhibitors for the treatment of advanced solid cancers: A literature-based meta-analysis of 46 randomised control trials

Background

The phosphatidylinositol-3- kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway (PI3K/AKT/mTOR pathway) plays a key role in cancer. We performed this meta-analysis to assess the clinical effect of using PI3K/AKT/mTOR pathway inhibitors on advanced solid tumours.

Methods

All the randomised controlled trials (RCT) that compared the therapy with PI3K/AKT/mTOR pathway inhibitors with other therapies were included. The main end-point was progression-free survival (PFS); other end-points included overall survival (OS) and objective response rate (ORR). A subgroup analysis was performed mainly for PFS.

Results

In total, 46 eligible RCT were included. The pooled results showed that PI3K/AKT/mTOR pathway inhibitor-based regimens significantly improved the PFS of patients with advanced solid tumours (hazard ratios (HR) = 0.79; 95% confidence intervals (CI): 0.71–0.88) and PI3K pathway mutations (HR = 0.69; 95% CI: 0.56–0.85). All single PI3K/AKT/mTOR pathway inhibitor therapies were compared with other targeted therapies (HR = 0.99; 95% CI: 0.93–1.06) and dual targeted therapies, including PI3K/AKT/mTOR pathway inhibitors and other targeted therapies (HR = 1.04; 95% CI: 0.62–1.74), which showed no significant differences in the PFS. Additional PI3K/AKT/mTOR pathway inhibitors showed no advantage with respect to the OS (HR = 0.98; 95% CI: 0.90–1.07) or ORR (risk ratio (RR) = 1.02; 95% CI: 0.87–1.20).

Conclusion

Our meta-analysis results suggest that the addition of the PI3K pathway inhibitors to the therapy regiment for advanced solid tumours significantly improves PFS. The way that patients are selected to receive the PI3K pathway inhibitors might be more meaningful in the future.

Pharmacokinetically-targeted dosed everolimus maintenance therapy in lymphoma patients

BACKGROUND

Everolimus, an mTOR inhibitor, is active in refractory lymphomas. However, toxicity with flat dosing limits its usage. Speculatively, pharmacokinetically-targeted dosing could improve tolerability. Therefore, we studied serum-trough dosing with rituximab as maintenance after high-dose cyclophosphamide (HDC) consolidation in lymphoma patients.

PATIENTS/METHODS

After HDC, everolimus was dosed to serum trough levels (goal 3-15 ng/mL), with quarterly rituximab infusions for 1 year while maintaining < grade II non-hematologic and < grade III hematologic toxicities. Adult patients in first PR/CR with: mantle cell, transformed, double-hit, or high risk chronic lymphocytic leukemia or in second PR for any relapsed B cell lymphoma were eligible. Prophylaxis was given for encapsulated organisms, HSV and PCP. Serum IgG levels were maintained > 500 mg/dL.

RESULTS

49 patients, median age: 59.0 years enrolled; MCL (26), CLL (10), transformed lymphoma (7), and other histologies (6). During the life of the study, the most frequent everolimus dosing has been 2.5 mg daily or 2.5 mg every other day; at these doses, serum levels are within the therapeutic range and non-hematologic toxicity is rare. At a median follow-up of 27.1 months, three patients remain on active therapy. Two patients withdrew secondary to potentially-attributable adverse events including a bacterial pneumonia and a viral pneumonia; this low rate of discontinuation compares well to other long-term everolimus trials. While a 58 and 76% EFS at 30 months for the entire cohort and MCL cohort, respectively, compares similarly to previously published HDC/rituximab data, longer follow-up is required.

CONCLUSIONS

Pharmacokinetically-targeted dosing appears to increase everolimus tolerability. This finding may be applicable to other patient populations.

PI3K/mTOR Inhibitors in the Treatment of Luminal Breast Cancer. Why, When and to Whom?

Estrogen receptor (ER) signaling represents the main driver of tumor growth and survival in luminal breast cancer (BC). Despite the efficacy of endocrine agents, many patients with luminal BC do not respond to endocrine therapy and many others develop endocrine resistance over time, due to the activation of escape pathways such as the PI3K/AKT/mTOR signaling. Several clinical trials have demonstrated the efficacy of mTOR and PI3K inhibitors in overcoming endocrine resistance in hormone receptor-positive human epidermal growth factor receptor 2 (HER2)-negative metastatic BC (MBC) patients. Nevertheless, to date, everolimus is the only agent targeting the PI3K/mTOR pathway that has been approved for clinical use. Recently, the introduction of CDK 4/6 inhibitors into clinical practice has significantly changed the therapeutic scenarios in luminal MBC. In the absence of direct comparisons among the new treatment combinations and predictive biomarkers of response, the choice of optimal therapeutic algorithms is very challenging. Future trials should focus on identifying more effective and safe combination therapies and defining the best treatment sequences in luminal BC.

Increased life expectancy as a result of non-hormonal targeted therapies for HER2 or hormone receptor positive metastatic breast cancer: A systematic review and meta-analysis

This article aimed to assess the clinical effectiveness of non-hormonal targeted therapies (TTs) in terms of increase of median progression-free survival (PFS) and overall survival (OS) in receptor-positive metastatic breast cancer (MBC) patients by performing a systematic review and meta-analysis. We systematically searched relevant randomized controlled trials and extracted data about number of patients on targeted and comparator therapy, receptor status, line of treatment, median PFS and OS, p values, hazard ratios (HRs) and 95% confidence intervals (CI). Inverse variance was used to estimate pooled HRs, chi-square test for heterogeneity and Jadad scale for quality were applied. Thirty-eight studies (n=17,192 patients) were eligible for inclusion. TTs added 3.3months to the median PFS [0.7-9.6; HRs 0.74, 95% CI 0.71-0.77] of receptor-positive MBC patients and prolonged their median OS with 3.5months [0-4.7; HRs 0.90, 95% CI 0.82-0.98]. The highest increase in median PFS of 3.6months was found in HER2-/hormone receptor(HR)+ patients, while the highest increase in median OS of 7.2months was observed in HER2+/HRmixed status patients. First-line TTs were most effective in increasing the median PFS in the HR+/HER2- group with 2.0months, and in the HER2+/HRmixed group by adding 4.7months to the median OS. Second-line TTs were most effective for HER2-/HR+ patients by adding 2.6months to their PFS, and for HER2+/HRmixed patients by adding 3.1months to their median OS. Albeit small, the gain in months of median PFS and median OS was significant. Importantly, the results reported show large variation, and thus routinely applying a personalized approach seems warranted.

Clinical results of randomized trials and 'real-world' data exploring the impact of Bevacizumab for breast cancer: opportunities for clinical practice and perspectives for research

INTRODUCTION

Angiogenesis plays a fundamental role in breast cancer (BC) growth, progression and metastatic spread. After the promising introduction of bevacizumab for the treatment of advanced BC, the initial enthusiasm decreased when the FDA withdrew its approval in 2011. Nevertheless, several clinical studies exploring the role of bevacizumab have been subsequently published. Areas covered: The aim of this study is to review the available clinical trials exploring the potential effectiveness of bevacizumab in BC, regardless of the disease setting. Expert opinion: Even if the evidence suggests that bevacizumab must be ruled out from the HER2-positive and adjuvant setting, bevacizumab's benefit remains uncertain in the neoadjuvant setting and in the advanced treatment of HER2-negative patients. In the first setting, the addition of bevacizumab to chemotherapy increased the pathological complete response (pCR) rate in most clinical trials. However, the current absence of evidence that pCR is a trial-level surrogate for survival requires waiting for long-term results. In the advanced setting, all trials showed a benefit in progression-free survival, but not in overall survival, highlighting an increase of adverse events. The lack of predictors of response represents the main unmet need in which future clinical research will undoubtedly invest.

Efficacy and safety of adding an agent to bevacizumab/taxane regimens for the first-line treatment of Her2-negative patients with locally recurrent or metastatic breast cancer: results from seven randomized controlled trials

Background

The combined therapy of bevacizumab (BEV) with taxane (paclitaxel or docetaxel) has shown an improvement on progression-free survival (PFS) and objective remission in Her2-negative patients with locally recurrent or metastatic breast cancer (LR/MBC). However, there was no benefit in overall survival (OS). The aim of this study was to evaluate the efficacy and safety of adding an agent to the BEV/taxane regimens for the treatment of Her2-negative patients with LR/MBC in a first-line setting.

Materials and methods

We searched PubMed, Web of Science, EMBASE, EBSCO, and the Cochrane Library databases for eligible trials. A meta-analysis was performed using Review Manager 5.0 freeware package. We calculated the hazard ratio (HR) for PFS and OS. The odds ratio (OR) was used to calculate objective response rate (ORR) and grade 3/4 drug-related adverse events. The heterogeneity of study outcomes was calculated by the χ² test or I² statistics.

Results

A total of 1,124 patients from seven randomized controlled trials were analyzed. Our meta-analysis showed that the ORR was significantly improved in the BEV/taxane-based triplet group when compared with the BEV/taxane-based doublet group (OR =1.31, 95% confidence interval [CI]: 1.03–1.67, P=0.03). A subset analysis showed that a similar result was achieved in the triplet group in which a cytotoxic agent was added (OR =1.46, 95% CI: 1.09–1.95, P=0.01). However, the PFS and OS had no statistically significant differences between the two groups (HR =0.87, 95% CI: 0.68–1.13, P=0.31; HR =0.98, 95% CI: 0.82–1.16, P=0.78, respectively). Regarding safety, thromboembolic events, fatigue, and diarrhea (all $grade 3) were more frequently observed in the BEV/taxane-based triplet group (OR =3.8, 95% CI: 1.86–7.79, P=0.0003; OR =1.55, 95% CI: 1.05–2.27, P=0.03; OR =2.1, 95% CI: 1.29–3.41, P=0.003, respectively). Other toxic effects had no statistically significant differences between the two groups.

Conclusion

Our results showed that adding an agent to BEV/taxane treatment regimens did not significantly improve PFS and prolong OS, except for conferring a significant advantage toward improved ORR in the first-line therapy for Her2-negative patients with LR/MBC. However, its side effects are predictable and manageable.