Overall survival (OS) endpoint: an incomplete evaluation of metastatic breast cancer (MBC) treatment outcome

Trends in endpoint use in pivotal trials and efficacy for US Food and Drug Administration–approved solid tumor therapies, 1995-2021

BACKGROUND: Many cancer therapies are now approved based on surrogate endpoints such as progression-free survival (PFS) to ensure that patients have speedy access to life-saving cancer medicines. However, the link between surrogate endpoints and overall survival (OS) is not well established in many cancers. OBJECTIVE: To characterize trends in endpoints used in pivotal trials leading to approval for US Food and Drug Administration (FDA)-approved solid tumor therapies and their efficacy from 1995 to 2021. METHODS: We reviewed the FDA Oncology (Cancer)/Hematologic Malignancies Approval Notifications webpage to extract data on median OS and PFS among solid tumor therapy approvals from 1995 to 2021. We summarized trends in percentage of trials reporting OS vs PFS, median OS and PFS, and trial designs. We conducted subgroup analyses for lung and breast cancer therapies. RESULTS: Median OS was reported more frequently until 2010 to 2012, when median PFS and OS were reported in 65.2% and 60.9% of trials, respectively. Between 1995 and 2021, there were no observable trends in median OS over time for solid tumor therapy approvals. Median PFS increased by 3.0 months over time. For lung cancer therapies, median OS increased by 6.8 months between the time periods of 1998-2000 and 2019-2021, whereas median PFS increased by 5.0 months between the time periods of 2007-2009 and 2019-2021. For breast cancer therapy, median OS slightly decreased over time, whereas median PFS has increased by 3.4 months since 1995. There has been a recent shift in use of single-arm trials leading to oncology drug approvals. CONCLUSIONS: There has been a transition from reporting OS to PFS, and median PFS has increased by 3 months while median OS has remained stable. The different trends in overall and progression-free survival highlights the challenge and importance of measuring the value of oncology drugs. DISCLOSURES: Dr Suh reports personal fees from Bayer US LLC.

Biases in study design, implementation, and data analysis that distort the appraisal of clinical benefit and ESMO-Magnitude of Clinical Benefit Scale (ESMO-MCBS) scoring

Background

The European Society for Medical Oncology-Magnitude of Clinical Benefit Scale (ESMO-MCBS) is a validated, widely used tool developed to score the clinical benefit from cancer medicines reported in clinical trials. ESMO-MCBS scores assume valid research methodologies and quality trial implementation. Studies incorporating flawed design, implementation, or data analysis may generate outcomes that exaggerate true benefit and are not generalisable. Failure to either indicate or penalise studies with bias undermines the intention and diminishes the integrity of ESMO-MCBS scores. This review aimed to evaluate the adequacy of the ESMO-MCBS to address bias generated by flawed design, implementation, or data analysis and identify shortcomings in need of amendment.

Methods

As part of a refinement of the ESMO-MCBS, we reviewed trial design, implementation, and data analysis issues that could bias the results. For each issue of concern, we reviewed the ESMO-MCBS v1.1 approach against standards derived from Helsinki guidelines for ethical human research and guidelines from the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use, the Food and Drugs Administration, the European Medicines Agency, and European Network for Health Technology Assessment.

Results

Six design, two implementation, and two data analysis and interpretation issues were evaluated and in three, the ESMO-MCBS provided adequate protections. Seven shortcomings in the ability of the ESMO-MCBS to identify and address bias were identified. These related to (i) evaluation of the control arm, (ii) crossover issues, (iii) criteria for non-inferiority, (iv) substandard post-progression treatment, (v) post hoc subgroup findings based on biomarkers, (vi) informative censoring, and (vii) publication bias against quality-of-life data.

Conclusion

Interpretation of the ESMO-MCBS scores requires critical appraisal of trials to understand caveats in trial design, implementation, and data analysis that may have biased results and conclusions. These will be addressed in future iterations of the ESMO-MCBS.

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We reviewed trial design, implementation, and data analysis issues that could bias the results of trials.

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These issues could skew the results of ESMO-MCBS scores.

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Six design, two implementation, and two analysis issues were reviewed, and seven shortcomings were identified.

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These issues will be addressed in future versions of the MCBS scale.

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Interpretation of MCBS scores requires critical appraisal of trials.

Aidi Injection as Adjuvant Drug Combined with Chemotherapy in Treatment of Breast Cancer: A Systematic Meta-Analysis

Objective

To compare the efficacy and safety of combination of Aidi injection and chemotherapy and chemotherapy alone in treatment of breast cancer.

Methods

The related control and randomized studies till August 1^st, 2020, were retrieved in the database including PubMed, Embase, Cochrane Library, CNKI, CBM, Wang-Fang, and VIP. Primary outcomes were response rate (RR) and performance status (KPS) improvement rate; secondary outcomes were rate of adverse drug reactions (ADR) including myelosuppression, digestive tract reaction, liver dysfunction, and cardiac toxicity. Review Manager 5.3 was used in the present analysis.

Results

In total, 20 studies (18 articles) were included in the present analysis. RR (OR 1.76 (1.32, 2.35); p=0.0001) and KPS improvement rate (OR: 2.68 (1.34, 6.46); p=0.007) in Aidi injection plus chemotherapy group were significantly higher than those of chemotherapy alone group. Addition of Aidi injection significantly reduced the rate of myelosuppression, digestive tract reaction, leukocyte decrease, II-IV cardiac function abnormality, atrial dysrhythmia, ventricular arrhythmia, ST segment T wave inversion, and abnormal ECG (all p < 0.05).

Conclusion

Aidi injection could increase the efficacy of chemotherapy, could reduce myelosuppression, digestive tract reaction, and cardiac toxicity induced by chemotherapy, and did not lead to additional toxicity and side effect. Therefore, it is an anticancer drug with good efficacy and low toxicity, worth further popularization.

The Evolution of Clinical Trials in Metastatic Breast Cancer: Design Features and Endpoints That Matter

The evolution of thought in assessing benefit in clinical trials of systemic therapy for metastatic breast cancer (MBC) is well documented, with most agents garnering regulatory approval based either on an advantage in overall survival (OS), time to progression (TTP), or progression-free survival (PFS) over an existing standard of care or objective response rate (ORR). Previous guidance for industry on clinical trial endpoints for the approval of cancer drugs and biologics was provided by the U.S. Food and Drug Administration (FDA) in 2007 and recently updated in 2018. The more recent FDA guidance recognizes that advances in science are facilitating the development of oncology products, which "may also result in the identification of additional endpoints that may be used to support approval of oncology products." This article critically addressed the evolution of thought on the advancement of clinical trials in MBC, from various stakeholder perspectives. Despite the term "stakeholder," the objective of all co-authors and parties concerned is to promote and inform the optimal design, conduct, and reporting of clinical trials for women with advanced breast cancer toward improving and extending lives. This article provides an overview of the evolving perspectives on this issue from the physician, regulatory agency, and patient and/or advocate points of view.

FDG-PET/CT Versus Contrast-Enhanced CT for Response Evaluation in Metastatic Breast Cancer: A Systematic Review

18F-fluorodeoxyglucose positron emission tomography with integrated computed tomography (FDG-PET/CT) and contrast-enhanced computed tomography (CT) can be used for response evaluation in metastatic breast cancer (MBC). In this study, we aimed to review literature comparing the PET Response Criteria in Solid Tumors (PERCIST) with Response Evaluation Criteria in Solid Tumors (RECIST) in patients with MBC. We made a systematic search in Embase, PubMed/Medline, and Cochrane Library using a modified PICO model. The population was MBC patients and the intervention was PERCIST or RECIST. Quality assessment was performed using the QUADAS-2 checklist. A total of 1975 articles were identified. After screening by title/abstract, 78 articles were selected for further analysis of which 2 duplicates and 33 abstracts/out of focus articles were excluded. The remaining 43 articles provided useful information, but only one met the inclusion and none of the exclusion criteria. This was a retrospective study of 65 patients with MBC showing one-year progression-free survival for responders versus non-responders to be 59% vs. 27% (p = 0.2) by RECIST compared to 64% vs. 0% (p = 0.0001) by PERCIST. This systematic literature review identified a lack of studies comparing the use of RECIST (with CE-CT) and PERCIST (with FDG-PET/CT) for response evaluation in metastatic breast cancer. The available sparse literature suggests that PERCIST might be more appropriate than RECIST for predicting prognosis in patients with MBC.

Visualization of Sequential Treatments in Metastatic Breast Cancer

PURPOSE

Treatment sequencing of metastatic breast cancer (MBC) is heterogeneous. The primary objective of this study was to develop a visualization technique to understand population-level treatment sequencing for MBC. Secondary outcomes were to describe the heterogeneity of MBC treatment sequencing, as measured by the proportion of patients with a rare sequence, and to generate hypotheses about the impact of sequencing on overall survival.

METHODS

This retrospective review evaluated treatment sequencing for patients with MBC in the SEER-Medicare database. Patients with either de novo MBC or International Classification of Diseases, Ninth Revision, diagnosis codes for secondary metastasis (197.XX-198.XX) on two separate dates, excluding breast (198.81, 198.82, 198.2) and lymph nodes (196.XX), were included. Complete Medicare Parts A, B, and D coverage was required. A treatment sequence that fewer than 11 patients received was considered rare. A graphic was created with each nonrare treatment-sequence grouping on the y-axis and time on the x-axis. Bars representing time on hormonal therapy, chemotherapy, human epidermal growth factor receptor 2-targeted therapy, and other targeted therapies were color coded. Kaplan-Meier-like curves were overlaid on treatment maps, using estimated median survival for each sequence.

RESULTS

Of 6,639 patients with MBC, 56% received a treatment sequence that fewer than 11 other patients received, with 2,985 other unique, rare sequences were identified. Sequence visualization demonstrated differential survival, with longer median survival for those initially receiving hormonal therapy. The median time receiving initial treatment was similar for patients receiving first-line chemotherapy.

CONCLUSION

Treatment-sequence visualization can enhance the capacity to effectively conceptualize treatment patterns and patient outcomes.

Network pharmacology-based and clinically relevant prediction of the active ingredients and potential targets of Chinese herbs in metastatic breast cancer patients

Chinese Herbal Medicine (CHM) plays a significant role in breast cancer treatment. We conduct the study to ascertain the relative molecular targets of effective Chinese herbs in treating stage IV breast cancer.Survival benefit of CHM was verified by Kaplan-Meier method and Cox regression analysis. A bivariate correlation analysis was used to find and establish the effect of herbs in complex CHM formulas. A network pharmacological approach was adopted to explore the potential mechanisms of CHM.Patients in the CHM group had a median survival time of 55 months, which was longer than the 23 months of patients in the non-CHM group. Cox regression analysis indicated that CHM was an independent protective factor. Correlation analysis showed that 10 herbs were strongly correlated with favorable survival outcomes (P<0.01). Bioinformatics analyses suggested that the 10 herbs might achieve anti-breast cancer activity primarily through inhibiting HSP90, ERα and TOP-II related pathways.

Ongoing unmet needs in treating estrogen receptor-positive/HER2-negative metastatic breast cancer

Estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2 negative (HER2-) advanced or metastatic breast cancer (MBC) is the most common MBC subtype and currently remains incurable, with a median overall survival of 24.8 months (95% confidence interval, 21.3-30.3). Common sites of metastases are bone, viscera, and brain, causing significant symptoms that negatively affect patient functioning, quality of life (QoL), and work productivity. Guidelines state that endocrine therapy (ET) is preferable to chemotherapy as first-line treatment for patients with ER+ MBC, regardless of limited visceral metastases, unless rapid tumor response is required or ET resistance is suspected. Although response rates up to 40% have been reported for first-line MBC treatment, the majority of initial responders eventually develop ET resistance. Notwithstanding the steep decline in efficacy between first and later lines of ET, some patients may receive chemotherapy earlier than necessary. Although new treatments have been approved for patients with ER+/HER2- advanced or MBC in the past decade, neither survival nor QoL appear to have improved significantly. Thus, there remain significant unmet needs for this patient population, including improved survival, maintaining or improving patient QoL, and emphasizing the importance of treatment selection to assist healthcare practitioners managing patient care. In this review, we identify current challenges and unmet needs in this patient population, review cutting-edge treatments, and provide clinically relevant suggestions for treatment selection that can optimize outcomes and patients' health-related QoL.

Reliability of an e-PRO Tool of EORTC QLQ-C30 for Measurement of Health-Related Quality of Life in Patients With Breast Cancer: Prospective Randomized Trial

BACKGROUND

Breast cancer represents the most common malignant disease in women worldwide. As currently systematic palliative treatment only has a limited effect on survival rates, the concept of health-related quality of life (HRQoL) is gaining more and more importance in the therapy setting of metastatic breast cancer. One of the major patient-reported outcomes (PROs) for measuring HRQoL in patients with breast cancer is provided by the European Organization for Research and Treatment of Cancer (EORTC). Currently, paper-based surveys still predominate, as only a few reliable and validated electronic-based questionnaires are available. Facing the possibilities associated with evolving digitalization in medicine, validation of electronic versions of well-established PRO is essential in order to contribute to comprehensive and holistic oncological care and to ensure high quality in cancer research.

OBJECTIVE

The aim of this study was to analyze the reliability of a tablet-based measuring application for EORTC QLQ-C30 in German language in patients with adjuvant and (curative) metastatic breast cancer.

METHODS

Paper- and tablet-based questionnaires were completed by a total of 106 female patients with adjuvant and metastatic breast cancer recruited as part of the e-PROCOM study. All patients were required to complete the electronic- (e-PRO) and paper-based versions of the HRQoL EORTC QLQ-C30 questionnaire. A frequency analysis was performed to determine descriptive sociodemographic characteristics. Both dimensions of reliability (parallel forms reliability [Wilcoxon test] and test of internal consistency [Spearman rho and agreement rates for single items, Pearson correlation and Kendall tau for each scale]) were analyzed.

RESULTS

High correlations were shown for both dimensions of reliability (parallel forms reliability and internal consistency) in the patient's response behavior between paper- and electronic-based questionnaires. Regarding the test of parallel forms reliability, no significant differences were found in 27 of 30 single items and in 14 of 15 scales, whereas a statistically significant correlation in the test of consistency was found in all 30 single items and all 15 scales.

CONCLUSIONS

The evaluated e-PRO version of the EORTC QLQ-C30 is reliable for patients with both adjuvant and metastatic breast cancer, showing a high correlation in almost all questions (and in many scales). Thus, we conclude that the validated paper-based PRO assessment and the e-PRO tool are equally valid. However, the reliability should also be analyzed in other prospective trials to ensure that usability is reliable in all patient groups.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03132506; https://clinicaltrials.gov/ct2/show/NCT03132506 (Archived by WebCite at http://www.webcitation.org/6tRcgQuou).

Optimizing the treatment of bevacizumab as first-line therapy for human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer: an updated meta-analysis of published randomized trials

Background

Manifold data have demonstrated that the addition of bevacizumab to chemotherapy improved progression-free survival (PFS), while few trials have revealed its significant overall survival (OS) benefit. Furthermore, it still remains suspended how to maximize the benefits of bevacizumab as first-line therapy for human epidermal growth factor receptor 2 (HER2)-negative breast cancer. We sought to conduct a meta-analysis to assess the benefits of bevacizumab with chemotherapy and to identify the ideal chemotherapy partner of bevacizumab in the first-line setting for HER2-negative advanced breast cancer patients.

Methods

Computerized and manual searches were performed to identify randomized clinical trials evaluating the efficacy of bevacizumab plus chemotherapy versus chemotherapy alone or bevacizumab with different chemotherapy regimens as first-line therapy for HER2-negative locally recurrent or metastatic breast cancer patients. Risk ratios or odds ratios with their 95% CIs were used to estimate the association between multiple combinations of bevacizumab with chemotherapy and various clinical outcomes.

Results

With 7 trials identified, this analysis included 3,984 eligible patients. The addition of bevacizumab to chemotherapy resulted in a statistically significant improvement in PFS (P=0.019) and objective response rate (ORR; P<0.001) rather than in OS (P=0.783) when compared with chemotherapy alone. The greater benefits in PFS and ORR were achieved from bevacizumab plus taxane-based regimens compared with bevacizumab plus capecitabine-based regimens, while bevacizumab plus capecitabine had comparable OS with bevacizumab plus paclitaxel. Additionally, bevacizumab-based triplet therapy failed to improve the clinical outcomes when compared with doublet therapy.

Conclusion

This meta-analysis reveals that the addition of bevacizumab to chemotherapy yielded PFS and ORR benefits in HER2-negative advanced breast cancer. Additional studies are still prompted to further optimize the first-line treatment of bevacizumab.

Anti-angiogenic treatment in breast cancer: Facts, successes, failures and future perspectives

Angiogenesis is one of the hallmarks of cancer and a crucial requisite in the development of tumors. Interrupting this process by blocking the vascular endothelial growth factor (VEGF) with the monoclonal antibody bevacizumab has been considered a possible breakthrough in the treatment of various types of cancer, especially for advanced disease. However in breast cancer, studies have shown ambivalent results causing debate about the value of this drug. In this article, we review the evidence for anti-angiogenic treatment options for breast cancer, as well as discuss the possible factors limiting the effectiveness of anti-angiogenic agents and offer a recommendation regarding the future research on these therapies for the treatment of breast cancer.

Final results of the TANIA randomised phase III trial of bevacizumab after progression on first-line bevacizumab therapy for HER2-negative locally recurrent/metastatic breast cancer

BACKGROUND

The randomised phase III TANIA trial demonstrated that continuing bevacizumab with second-line chemotherapy for locally recurrent/metastatic breast cancer (LR/mBC) after progression on first-line bevacizumab-containing therapy significantly improved progression-free survival (PFS) compared with chemotherapy alone [hazard ratio (HR) = 0.75, 95% confidence interval (CI) 0.61-0.93]. We report final results from the TANIA trial, including overall survival (OS) and health-related quality of life (HRQoL).

PATIENTS AND METHODS

Patients with HER2-negative LR/mBC that had progressed on or after first-line bevacizumab plus chemotherapy were randomised to receive standard second-line chemotherapy either alone or with bevacizumab. At second progression, patients initially randomised to bevacizumab continued bevacizumab with their third-line chemotherapy, but those randomised to chemotherapy alone were not allowed to cross over to receive third-line bevacizumab. The primary end point was second-line PFS; secondary end points included third-line PFS, combined second- and third-line PFS, OS, HRQoL and safety.

RESULTS

Of the 494 patients randomised, 483 received second-line therapy; 234 patients (47% of the randomised population) continued to third-line study treatment. The median duration of follow-up at the final analysis was 32.1 months in the chemotherapy-alone arm and 30.9 months in the bevacizumab plus chemotherapy arm. There was no statistically significant difference between treatment arms in third-line PFS (HR = 0.79, 95% CI 0.59-1.06), combined second- and third-line PFS (HR = 0.85, 95% CI 0.68-1.05) or OS (HR = 0.96, 95% CI 0.76-1.21). Third-line safety results showed increased incidences of proteinuria and hypertension with bevacizumab, consistent with safety results for the second-line treatment phase. No differences in HRQoL were detected.

CONCLUSIONS

In this trial, continuing bevacizumab beyond first and second progression of LR/mBC improved second-line PFS, but no improvement in longer term efficacy was observed. The second-line PFS benefit appears to be achieved without detrimentally affecting quality of life.

CLINICALTRIALSGOV

NCT01250379.

A Delphi consensus and open debate on the role of first-line bevacizumab for HER2-negative metastatic breast cancer

To gain consensus on the role of bevacizumab plus paclitaxel as first-line treatment for HER2-negative metastatic breast cancer, a panel of expert oncologists experienced in treating patients with metastatic breast cancer in Italy participated in a Delphi consensus study. The panel reached a full consensus on the efficacy of bevacizumab plus paclitaxel and the clinical meaningfulness of the progression-free survival benefit compared with paclitaxel alone, despite the lack of an overall survival effect in clinical trials. The participants agreed that real-world data support the effectiveness and well-defined safety profile of the regimen. Views on the use of bevacizumab plus paclitaxel in specific patient populations were not unanimous and clinical judgment remains important. Nevertheless, a high level of agreement was reached.