Correlation between overall survival and other endpoints in metastatic breast cancer with second- or third-line chemotherapy: Literature-based analysis of 24 randomized trials

Modelling approaches for histology-independent cancer drugs to inform NICE appraisals: a systematic review and decision-framework

BACKGROUND

The first histology-independent marketing authorisation in Europe was granted in 2019. This was the first time that a cancer treatment was approved based on a common biomarker rather than the location in the body at which the tumour originated. This research aims to explore the implications for National Institute for Health and Care Excellence appraisals.

METHODS

Targeted reviews were undertaken to determine the type of evidence that is likely to be available at the point of marketing authorisation and the analyses required to support National Institute for Health and Care Excellence appraisals. Several challenges were identified concerning the design and conduct of trials for histology-independent products, the greater levels of heterogeneity within the licensed population and the use of surrogate end points. We identified approaches to address these challenges by reviewing key statistical literature that focuses on the design and analysis of histology-independent trials and by undertaking a systematic review to evaluate the use of response end points as surrogate outcomes for survival end points. We developed a decision framework to help to inform approval and research policies for histology-independent products. The framework explored the uncertainties and risks associated with different approval policies, including the role of further data collection, pricing schemes and stratified decision-making.

RESULTS

We found that the potential for heterogeneity in treatment effects, across tumour types or other characteristics, is likely to be a central issue for National Institute for Health and Care Excellence appraisals. Bayesian hierarchical methods may serve as a useful vehicle to assess the level of heterogeneity across tumours and to estimate the pooled treatment effects for each tumour, which can inform whether or not the assumption of homogeneity is reasonable. Our review suggests that response end points may not be reliable surrogates for survival end points. However, a surrogate-based modelling approach, which captures all relevant uncertainty, may be preferable to the use of immature survival data. Several additional sources of heterogeneity were identified as presenting potential challenges to National Institute for Health and Care Excellence appraisal, including the cost of testing, baseline risk, quality of life and routine management costs. We concluded that a range of alternative approaches will be required to address different sources of heterogeneity to support National Institute for Health and Care Excellence appraisals. An exemplar case study was developed to illustrate the nature of the assessments that may be required.

CONCLUSIONS

Adequately designed and analysed basket studies that assess the homogeneity of outcomes and allow borrowing of information across baskets, where appropriate, are recommended. Where there is evidence of heterogeneity in treatment effects and estimates of cost-effectiveness, consideration should be given to optimised recommendations. Routine presentation of the scale of the consequences of heterogeneity and decision uncertainty may provide an important additional approach to the assessments specified in the current National Institute for Health and Care Excellence methods guide.

FURTHER RESEARCH

Further exploration of Bayesian hierarchical methods could help to inform decision-makers on whether or not there is sufficient evidence of homogeneity to support pooled analyses. Further research is also required to determine the appropriate basis for apportioning genomic testing costs where there are multiple targets and to address the challenges of uncontrolled Phase II studies, including the role and use of surrogate end points.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Evidence Synthesis programme and will be published in full in Health Technology Assessment; Vol. 25, No. 76. See the NIHR Journals Library website for further project information.

Surrogate Endpoints in Oncology: Overview of Systematic Reviews and Their Use for Health Decision Making in Mexico

OBJECTIVES

The use of surrogate endpoints (SEs) for cancer drug approval in health systems is common. The objectives of this study were to identify systematic reviews (SRs) that evaluated the correlation of SEs with overall survival (OS) in cancer drugs to analyze the applications of approved cancer drugs with SEs in Mexico and to apply the validation framework proposed by the Institute for Quality and Efficiency in Health Care (IQWiG).

METHODS

An overview of SRs was conducted according to Cochrane Collaboration methodology. Applications for approved cancer drugs with SEs in Mexico were analyzed. The IQWiG validation framework was applied to evaluate the SEs identified in the overview and in the applications in Mexico.

RESULTS

A total of 85 SRs that assessed 192 SEs for different types of cancer were selected. According to the IQWiG model, only 2.5% of the SEs analyzed in the overview and only one of the applications in Mexico could be used as surrogates for OS because the reliability (methodological quality) of the SRs and the strength of the correlation of SEs with OS was mostly low (92%) and low (correlation coefficient r ≤ 0.7; 50.5%), respectively. Of the total number of cancer drugs approved in Mexico, 19.4% used SEs.

CONCLUSIONS

Most SEs for different types of cancer could not be used as surrogates for OS according to the IQWiG model, and their use for the approval of cancer drugs in Mexico is generally not justified.

Associations of Estrogen Receptor, Progesterone Receptor, Human Epidemic Growth Factor Receptor-2 and Ki-67 with Ultrasound Signs and Prognosis of Breast Cancer Patients

Objective

The functions of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and Ki-67 in breast cancer have been explored. This study was carried out to explore ER, PR, HER-2 and Ki-67 expression levels in breast cancer patients and their relationship with ultrasound signs and prognosis.

Patients and Methods

A total of 274 female primary breast cancer patients received preoperative ultrasound examination. ER, PR, HER-2 and Ki-67 expression levels in breast cancer tissues were detected by immunohistochemical staining after surgery. The correlations of ER, PR, HER-2 and Ki-67 expression with ultrasound signs and prognosis of breast cancer patients were analyzed.

Results

The positive expression rate of ER, PR and HER-2 and Ki-67 high expression in 274 breast cancer patients was 73.36% (201/274), 59.85% (164/274), 24.09% (66/274) and 66.06% (181/274), respectively. ER-positive expression had association with lymph node metastasis (LNM) and blood flow grading; HER-2-positive expression was associated with LNM, while Ki-67-positive expression was related to the tumor diameter, LNM, and blood flow grading. LNM and Ki-67 high expression were risk factors for OS; PR-positive was a protective factor for OS; TNM stage, tumor diameter, LNM and Ki-67 high expression were risk factors for DFS in breast cancer patients.

Conclusion

ER, PR, HER-2 and Ki-67 in breast cancer are related to the ultrasound signs and prognosis of breast cancer patients. The joint detection of multiple indicators provides a reference for the individualized treatment of targeted drugs.

A systematic review of meta-analyses assessing the validity of tumour response endpoints as surrogates for progression-free or overall survival in cancer

BACKGROUND

Tumour response endpoints, such as overall response rate (ORR) and complete response (CR), are increasingly used in cancer trials. However, the validity of response-based surrogates is unclear. This systematic review summarises meta-analyses assessing the association between response-based outcomes and overall survival (OS), progression-free survival (PFS) or time-to-progression (TTP).

METHODS

Five databases were searched to March 2019. Meta-analyses reporting correlation or regression between response-based outcomes and OS, PFS or TTP were summarised.

RESULTS

The systematic review included 63 studies across 20 cancer types, most commonly non-small cell lung cancer (NSCLC), colorectal cancer (CRC) and breast cancer. The strength of association between ORR or CR and either PFS or OS varied widely between and within studies, with no clear pattern by cancer type. The association between ORR and OS appeared weaker and more variable than that between ORR and PFS, both for associations between absolute endpoints and associations between treatment effects.

CONCLUSIONS

This systematic review suggests that response-based endpoints, such as ORR and CR, may not be reliable surrogates for PFS or OS. Where it is necessary to use tumour response to predict treatment effects on survival outcomes, it is important to fully reflect all statistical uncertainty in the surrogate relationship.

Real-life activity of eribulin mesylate among metastatic breast cancer patients in the multicenter national observational ESME program

Eribulin mesylate (EM) was recently approved for metastatic breast cancer (MBC) chemotherapy (CT) in late lines by the FDA, with debated results in second line. We evaluated outcomes in breast cancer patients receiving EM as second, third and fourth line in a national real-life cohort of 16,703 consecutive MBC patients initiating their first metastatic therapeutic line between 2008 and 2014. Primary and secondary objectives were overall survival (OS) and progression-free survival (PFS). An imbalance was seen for HER2+ tumors and concomitant anti-HER2 targeted therapies use, we thus performed a subanalysis in HER2- patients. PFS and OS were significantly better in EM patients in third and fourth lines, compared to "Other chemotherapies" patients (PFS: 4.14 vs. 3.02 months, p = 0.0010; 3.61 vs. 2.53 months, p = 0.0102, third and fourth-line; OS: 11.27 vs. 7.65 months, p = 0.0001; 10.91 vs. 5.95 months, p < 0.0001, third and fourth-line). No significant difference was reported in second-line (PFS: 5.06 vs. 4.14 months, p = 0.1171; OS: 13.99 vs. 11.66 months, p = 0.151). Among HER2- patients, a significant difference was seen for all lines, including 2nd-line (PFS: 4.57 vs. 3.91 months, p = 0.0379; OS: 14.98 vs. 10.51 months, p = 0.0113). In this large real-world database, HER2-negative MBC patients receiving EM in second or later CT line presented significantly better PFS and OS. This difference disappeared in second line in the overall population, probably because of the imbalance in HER2-targeted treatments use. Our results mirror those of the published randomized trials. The effect of anti-HER2 therapies addition in this setting still needs to be defined.

Intra-arterial Mitomycin C infusion in a large cohort of advanced liver metastatic breast cancer patients: safety, efficacy and factors influencing survival

PURPOSE

The aim of this study was to determine the safety and efficacy of Mitomycin C (MMC) infusion in a large cohort of advanced liver metastatic breast cancer patients (LMBC) and to determine factors influencing overall survival (OS).

METHODS

We retrospectively analysed LMBC patients, treated with MMC infusion between 2000 and 2017. Hepatic response was measured with baseline CT scans and first available CT scan after MMC infusion by RECIST 1.1 criteria. Adverse events were registered by the CTCAE version 5.0. OS and hepatic progression free survival (hPFS) were evaluated using Kaplan-Meier estimates. After univariable analysis, a stepwise forward multivariable (MV) prediction analysis was developed to select independent pre-treatment factors associated with OS.

RESULTS

We included 176 patients with a total of 599 MMC infusions, mostly heavily pre-treated patients with a median time from diagnosis of MBC to MMC infusion of 36.9 months. RECIST evaluation of liver lesions (n = 132) showed a partial response rate of 15%, stable disease of 43% and progressive disease in 17%. Adverse events grade 3 and 4 were reported in 17.5%. Median PFS was 5.5 months and median OS was 7.8 months. Significant independent baseline predictors of worse OS included number of prior systemic chemotherapy lines, prior liver ablation, higher liver tumour burden and elevated levels of bilirubin and ALT.

CONCLUSION

MMC infusion is safe and effective in advanced LMBC patients. An increased number of prior therapies, a higher liver tumour burden and elevated levels of bilirubin and ALT were associated with a worse OS.

Combined Detection of HER2, Ki67, and GSTP1 Genes on the Diagnosis and Prognosis of Breast Cancer

OBJECTIVE

Breast cancer (BC) is a common malignant tumor in females. The combined assay of multiple molecular markers benefits the diagnosis and prognostic prediction. Human epidermal growth factor receptor 2 (HER2) facilitates the proliferation and differentiation of cancer cells through ligand binding. Ki67 is a tumor proliferation-related gene, whereas GSTP1 is a DNA repair-related gene. This study thus investigated the significance of HER2 and Ki67/GSTP1 gene combined assay in the diagnosis and prognosis of BC.

MATERIALS AND METHODS

A total of 86 breast tumor tissues and adjacent tissues were collected. Gene expression and protein levels of HER2 and Ki67 were quantified by real-time polymerase chain reaction (PCR) and Western blot, respectively. Methylation frequency of GSTP1 was analyzed by methylation-specific PCR. The correlation between HER2 and Ki67/GSTP1 and clinical/pathological features of BC was analyzed.

RESULTS

Gene and protein expression levels of HER2 and Ki67 in tumor tissues were increased (p < 0.05 compared with adjacent tissues). Methylation frequency of GSTP1 gene was 37.2%, which was significantly higher in breast tumor tissues than in adjacent tissues (12.79%, p < 0.05). HER2 expression was positively correlated with TNM stage, tumor size, and lymph node metastasis, and negatively correlated with tissue grade and estrogen receptor (ER)/progesterone receptor (PR) expression (p < 0.05). GSTP1 methylation was positively correlated with TNM stage and tumor size, and negatively correlated with ER/PR expression (p < 0.05).

CONCLUSIONS

HER2, Ki67, and GSTP1 methylation were correlated with clinical and pathological features of BC. The combined assay benefits the early diagnosis and prognostic prediction of cancer.

Can contemporary trials of chemotherapy for HER2-negative metastatic breast cancer detect overall survival benefit?

PURPOSE

Although several trials have demonstrated improved progression-free survival (PFS) with first-line regimens for HER2-negative metastatic breast cancer (mBC), overall survival (OS) benefit is elusive. We calculated required sample sizes to power for OS using published data from recent mBC trials.

PATIENTS AND METHODS

Randomized superiority trials of first-line chemotherapy/targeted therapy for HER2-negative mBC including >150 patients, meeting the primary efficacy objective, and published in 2000-2018 were identified. The sample sizes required to power for PFS and OS were calculated retrospectively for each trial using observed results and study/recruitment follow-up durations (α=0.05, two-sided log-rank test, 80% power), and summarized as a factor (x) relative to actual sample size.

RESULTS

Nine of 13 identified trials reported all information required for retrospective sample size calculation. Six had sample sizes larger than required to demonstrate a significant PFS benefit but all would have required larger sample sizes to demonstrate significant OS benefit with the observed results. In ten trials, the required sample size was ≥5-fold larger to power for OS than PFS.

CONCLUSION

Designing trials to test potential new treatments for HER2-negative mBC is challenging, requiring a balance of regulatory acceptability, feasibility, and realistic medical assumptions to calculate sample sizes. Powering for OS is particularly difficult in heterogeneous populations with long postprogression survival, potential crossover, heterogeneous poststudy therapy, and evolving treatment standards. Validated surrogate endpoints are critical. Ongoing trials of cancer immunotherapy (new mode of action) in triple-negative mBC (more homogeneous, shorter OS and postprogression survival, fewer treatment options) may show a new pattern.

Oral etoposide in heavily pre-treated metastatic breast cancer: results from the ESME cohort and comparison with other chemotherapy regimens

INTRODUCTION

HER2-negative metastatic breast cancer (MBC) is a common setting in which chemotherapy could be effective even in later lines of treatment. Oral etoposide has demonstrated clinical activity in this setting in small-scale studies, but its efficacy has not been compared to that of other chemotherapy regimens.

METHODS

We used the ESME database (Epidemiological Strategy and Medical Economics), a real-life national French multicentre cohort of MBC patients initiating therapy between 1 January 2008 to 31 December 2014. HER2-negative MBC patients who received oral etoposide as > 3rd chemotherapy line and for more than 14 days were included. Primary objective was progression-free survival (PFS); secondary objectives were overall survival (OS), and propensity-score matched Cox models including comparison with other therapies in the same setting.

RESULTS

Three hundred forty-five out of 16,702 patients received oral etoposide and 222 were eligible. Median PFS was 3.2 months [95% CI 2.8-4] and median OS 7.3 months [95% CI 5.7-10.3]. Median PFS did not significantly differ according to the therapeutic line. The only prognostic factor for both PFS and OS was the MBC phenotype (hormone receptor-positive versus triple-negative, HR = 0.71 [95% CI 0.52-0.97], p = 0.028 for PFS and HR = 0.65 [0.46-0.92], p = 0.014 for OS). After matching for the propensity score, no differential effect on PFS or OS was observed between oral etoposide and other chemotherapy regimens administered in the same setting (HR = 0.94 [95% CI 0.77-1.15], p = 0.55 for PFS and HR = 1.10 [95% CI 0.88-1.37], p = 0.40 for OS).

CONCLUSION

Oral etoposide retains some efficacy in selected heavily pre-treated patients with HER2-negative MBC, with the advantages of oral administration.

Balancing early access with uncertainties in evidence for drugs authorized by prospective case series - systematic review of reimbursement decisions

Aims

To review clinical and cost‐effectiveness evidence underlying reimbursement decisions relating to drugs whose authorization mainly is based on evidence from prospective case series.

Methods

A systematic review of all new drugs evaluated in 2011–2016 within a health care profession‐driven resource prioritization process, with a market approval based on prospective case series, and a reimbursement decision by the Swedish Dental and Pharmaceutical Benefits Agency (TLV). Public assessment reports from the European Medicines Agency, published pivotal studies, and TLV, Scottish Medicines Consortium and National Institute of Health and Care Excellence decisions and guidance documents were reviewed.

Results

Six drug cases were assessed (brentuximab vedotin, bosutinib, ponatinib, idelalisib, vismodegib, ceritinib). The validity of the pivotal studies was hampered by the use of surrogate primary outcomes and the absence of recruitment information. To quantify drug treatment effect sizes, the reimbursement agencies primarily used data from another source in indirect comparisons. TLV granted reimbursement in five cases, compared with five in five cases for Scottish Medicines Consortium and four in five cases for National Institute of Health and Care Excellence. Decision modifiers, contributing to granted reimbursement despite hugely uncertain cost‐effectiveness ratios, were, for example, small population size, occasionally linked to budget impact, severity of disease, end of life and improved life expectancy.

Conclusion

For drugs whose authorization is based on prospective case series, most applications for reimbursement within public health care are granted. The underlying evidence has limitations over and above the design per se, and decision modifiers are frequently referred to in the value‐based pricing decision making.