Pilot trial of paclitaxel-trastuzumab adjuvant therapy for early stage breast cancer: a trial of the ECOG-ACRIN cancer research group (E2198)

Targeting HER2 in breast cancer: new drugs and paradigms on the horizon

About 15-20% of all breast cancers (BCs) are defined human epidermal growth factor receptor 2 (HER2)-positive, based on the overexpression of HER2 protein and/or amplification of ERBB2 gene. Such alterations lead to a more aggressive behavior of the disease, but also predict response to treatments targeting HER2. Indeed, several anti-HER2 compounds have been developed and approved in the last two decades, significantly improving our ability to cure patients in the early setting, and greatly extending their survival in the advanced setting. However, recent evolutions in this field promise to improve outcomes even further, through advancements in established HER2-targeting strategies, as well as the exploration of novel strategies. In particular, the engineering of new antibody-drug conjugates, with higher drug-to-antibody ratios (DARs) and cleavable linkers, has already led to the development of a highly effective drug, namely trastuzumab deruxtecan, recently approved by the Food and Drug Administration (FDA) and European Medicines Agency (EMA) for the treatment of advanced HER2-positive (HER2+) BC, and currently in study in the early setting. Moreover, the novel tyrosine kinase inhibitor tucatinib was recently approved by FDA and EMA, showing to improve survival of HER2+ advanced BC patients, particularly in those with brain metastasis. Immunotherapy is also being investigated in the HER2+ subtype, through immune-checkpoint inhibition, cancer vaccines and adoptive-cell therapies. Overall, the enlarging arsenal of promising anti-HER2 compounds is expected to deliver significant improvements in the prognosis of both early and advanced HER2+ BC in the years to come. Moreover, some of such agents are showing encouraging activity in the much wider population of HER2-low advanced BC patients, challenging current BC classifications. If confirmed, this new paradigm would potentially expand the population deriving benefit from HER2-targeted treatments to up to 70% of all advanced BC patients, leading to a revolution in current treatment algorithms, and possibly to a redefinition of HER2 classification.

Neoadjuvant chemotherapy with biosimilar trastuzumab in human epidermal growth factor receptor 2 overexpressed non-metastatic breast cancer: patterns of use and clinical outcomes in India

BACKGROUND

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer is associated with poor prognosis and access to anti-HER2 treatment is still a challenge in lower-middle income countries. The availability of the biosimilar trastuzumab has improved access by lowering the costs. We report the pattern of use of neoadjuvant ± adjuvant trastuzumab and outcomes in patients with HER2-positive non-metastatic breast cancer treated with regimens incorporating shorter durations of therapy and the use of the biosimilar trastuzumab compared to the innovator.

METHODS

We conducted a retrospective analysis of patients with non-metastatic HER2-positive breast cancer treated with neoadjuvant ± adjuvant trastuzumab (innovator (n = 34 (33%)) and biosimilar (n = 70 (67%)) manufactured by Biocon Biologics) with chemotherapy. Information regarding chemotherapy regimens, duration of trastuzumab use (≤12 weeks and >12 weeks), pathological response (Miller Payne grade), disease free survival (DFS), overall survival (OS) and safety data were collected from electronic medical records.

RESULTS

A total of 135 patients were analysed with a median age of 51 years (range: 23-82); of these, 57% were postmenopausal, 31.8% were hormone receptor positive and 62.9% had stage III disease. The overall pathological complete response (p-CR) in both breast and axilla increased to 37.6% in patients treated with trastuzumab preoperatively as compared to 22.2% in patients who did not receive any trastuzumab. Patients receiving innovator trastuzumab and biosimilar trastuzumab showed a p-CR of 28.5% and 41.7%, respectively. At a median follow-up of 42 months (range: 3-114), there were 18 relapses and 11 deaths. The 3-year DFS was 87.1% and OS was 92.2%. Cardiac dysfunction developed in 4 of 78 (5.1%) evaluable patients.

CONCLUSION

Access to anti-HER2 therapy in the treatment of non-metastatic HER2-positive breast cancer in resource-constrained settings has improved significantly with the availability of the biosimilar trastuzumab. Imbalances in patient profiles at baseline in routine clinical practice led to inconclusive outcomes of ≤12 weeks versus >12 weeks trastuzumab treatment. However, on the basis of historical data, patients could be offered shorter duration of trastuzumab when a standard 1-year treatment of adjuvant trastuzumab is not feasible in resource-constrained settings. The p-CR using the biosimilar trastuzumab in neoadjuvant treatment has been observed to be comparable to the innovator trastuzumab.

6 versus 12 months of adjuvant trastuzumab in HER2+ early breast cancer: A systematic review and meta-analysis

BACKGROUND

Adjuvant trastuzumab improves survival outcomes of human epidermal receptor 2 positive early breast cancer patients. Currently, administration of 12 months adjuvant trastuzumab is the standard therapy. However, whether 6 months treatment is non-inferior to the standard 12 months treatment remains controversial.

METHODS

Relevant records were searched in PubMed, Cochrane Library, Web of Science, and EMBASE through Jan 14, 2020. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) for disease-free survival (DFS) and overall survival (OS) were meta-analyzed. The primary endpoint was DFS with a non-inferiority hazard margin of 1.2 and the second was OS with 1.43.

RESULTS

Three randomized clinical studies met the inclusion criteria, including 3974 patients in 6 months group and 3976 in 12 months group. HR for DFS was 1.18 (95% CI 0.97-1.44, P = .09), with the non-inferiority margin comprised in the 95% CI. HR for OS was 1.14 (95% CI 0.98-1.32, P= .08), whereas the upper limit of 95% CI did not exceed the non-inferiority hazard margin.

CONCLUSION

Our analysis failed to show that 6 months treatment was non-inferior to 12 months treatment in improving the DFS. Although the non-inferiority of the 6-month adjuvant trastuzumab treatment was found for OS, considering that breast cancer patients should receive additional systematic therapies when disease progression or relapse happens, we suggest that 12 months adjuvant trastuzumab treatment should remain the standard therapeutic strategy for patients with early human epidermal receptor 2 positive breast cancer.

Optimum duration of adjuvant trastuzumab in treatment of human epidermal growth factor receptor-2 positive early breast cancer: protocol for a network meta-analysis of randomised controlled trials

INTRODUCTION

Controversy regarding optimum duration of trastuzumab treatment remains in patients with human epidermal growth factor receptor-2 (HER2) positive early breast cancer. The objective of applying network meta-analysis (NMA) is to integrate existing evidence based on direct and indirect comparisons of efficacy and safety, and then to determine the duration of trastuzumab treatments with the greatest impact on therapeutic outcomes in HER2-positive early breast cancers.

METHODS AND ANALYSIS

Electronic searching of trastuzumab treatments for early breast cancer by titles and abstracts will be conducted for the period from inception to 16 June 2019 in PubMed, Cochrane Library, Embase and ClinicalTrils.gov, as well as the annual meetings of San Antonio Breast Cancer Symposium (SABCS), European Society of Medical Oncology (ESMO) and American Society of Clinical Oncology (ASCO) online archives. The outcomes of interest are overall survival, disease-free survival, acceptability, cardiotoxicities and grade 3 to 4 non-haematological toxicities. Two independent reviewers will screen and extract eligible data based on the inclusion and exclusion criteria, and then assess the risk of bias and evidence quality of individual studies using Cochrane Collaboration's tool and Grades of Recommendation, Assessment, Development and Evaluation (GRADE). The heterogeneity, transitivity and inconsistency of NMA will be evaluated. In addition, we will perform subgroup and sensitivity analyses to assess the robustness and reliability of findings in our NMA.

ETHICS AND DISSEMINATION

Ethics approval is not required for our NMA. Findings from our NMA will be submitted as peer-reviewed journal manuscripts and international conference reports.

TRIAL REGISTRATION NUMBER

CRD42019139109.

Risk-based Approaches for Optimizing Treatment in HER2-Positive Early Stage Breast Cancer

Advancements in the care for patients with early stage HER2-positive breast cancer is a story of incremental successes aimed at optimizing efficacy and reducing the toxicities of administered therapies. HER2 drives an aggressive breast cancer subtype that represents 15%-20% of breast cancers, for which HER2-targeted therapy is very active. In addition to trastuzumab, pertuzumab, neratinib, and ado-trastuzumab emtansine have been approved in recent years for the treatment of high-risk early stage HER2-positive breast cancer. As a result of both a high response rate to neoadjuvant therapy and the opportunity for response-adapted adjuvant therapy, the treatment paradigm has evolved so that most patients with stage II and III disease now receive neoadjuvant therapy. Additionally, the efficacy of HER2-therapy allows for de-escalation of treatment in many patients with stage I disease. As a result, multidisciplinary evaluation is essential for the optimal care of patients with HER2-positive breast cancer. Important areas of further research include tailoring the duration and intensity of therapy based on disease risk and response to neoadjuvant therapy. This article will review the evaluation of patients with early stage HER2-positive breast cancer and provide an evidence- and guideline-based summary of risk-based treatment strategies.

Tailored duration of adjuvant trastuzumab for human epidermal growth factor receptor 2-positive breast cancer

We assumed that the effect of adjuvant trastuzumab on survival is mediated by the treatment time and we conducted this trial-level meta-regression to determine the appropriate length of treatment. Twelve adjuvant trastuzumab trials (from January 2000 to June 2019, consisting of 20,271 patients) were included. We considered 12-month trastuzumab treatment as the standard. The primary study endpoint was disease-free survival (DFS). By quantifying the relationship between shortened treatment time (month) and altered recurrence risk (expressed as hazard ratio), we found the regression coefficient β was 0.05 (95% confidence interval: 0.02–0.08, P = 0.002), indicating the recurrence risk would increase 5.1% for each month that treatment was shortened. Accordingly, 3, 6, and 9-month reductions in treatment time resulted in 16%, 35%, and 57% increases in recurrence risk, respectively. We revealed a significant linear association between shortened treatment time of trastuzumab and recurrence risk. The clinical duration of adjuvant trastuzumab should be tailored.

Evaluation of 1-Year vs Shorter Durations of Adjuvant Trastuzumab Among Patients With Early Breast Cancer: An Individual Participant Data and Trial-Level Meta-analysis

IMPORTANCE

The optimum duration of adjuvant trastuzumab among patients with early breast cancer is uncertain but of great therapeutic relevance.

OBJECTIVE

To compare shorter durations with 1 year of adjuvant trastuzumab for patients with early breast cancer.

DATA SOURCES

PubMed, Embase, Cochrane Central Register of Clinical Trials, and conference proceedings were searched from January 1, 2005, to June 30, 2019, for relevant randomized clinical trials (RCTs).

STUDY SELECTION

To be eligible, the trial had to be randomized, compare a shorter duration with 1 year of trastuzumab as adjuvant treatment, and include patients with early breast cancer.

DATA EXTRACTION AND SYNTHESIS

Individual patient data for disease-free survival (DFS) and overall survival (OS) were extracted from published survival curves of included RCTs; DFS and OS curves for each trial and the combined population were reconstructed. The DFS and OS hazard ratios (HRs) were estimated from the reconstructed survival curves as well as published estimates. The HR for DFS was used to test noninferiority using the median noninferiority margin of eligible RCTs. This study followed Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline.

MAIN OUTCOMES AND MEASURES

The primary outcome was DFS; OS and cardiac toxic effects were secondary outcomes.

RESULTS

There were 6 eligible RCTs with a median DFS noninferiority margin of 1.3 (range, 1.15-1.53), 5 of which had extractable individual patient data for 11 376 patients, 1659 DFS events, and 871 deaths. For shorter duration vs 1 year of trastuzumab, the 5-year DFS was 85.42% (95% CI, 84.41%-86.38%) vs 87.12% (95% CI, 86.15%-88.02%) (HR, 1.14; 95% CI, 1.03-1.25, 1-sided P for noninferiority = .004), and OS was 92.39% (95% CI, 91.61%-93.10%) vs 93.46% (95% CI, 92.73%-94.13%) (HR, 1.17; 95% CI, 1.02-1.33). Using trial-level published estimates from 6 RCTs, including 11 603 patients, 1760 DFS events, and 930 deaths, the HR for DFS was 1.15 (95% CI, 1.04-1.26; 1-sided P for noninferiority = .002) and, for OS, 1.17 (95% CI, 1.03-1.33). There was significantly less risk of congestive heart failure with shorter-duration trastuzumab (relative risk, 0.53; 95% CI, 0.38-0.74).

CONCLUSIONS AND RELEVANCE

In this study, a shorter duration of adjuvant trastuzumab was noninferior to its 1-year administration and resulted in lower rates of cardiac toxic effects. These results suggest that a shorter duration may be the preferred option for patients with low-risk disease or a predisposition to cardiac toxic effects.

Six versus 12 months' adjuvant trastuzumab in patients with HER2-positive early breast cancer: the PERSEPHONE non-inferiority RCT

BACKGROUND

The addition of adjuvant trastuzumab to chemotherapy has significantly improved outcomes for people with human epidermal growth factor receptor 2 (HER2)-positive, early, potentially curable breast cancer. Twelve months' trastuzumab, tested in registration trials, was adopted as standard adjuvant treatment in 2006. Subsequently, similar outcomes were demonstrated using 9 weeks of trastuzumab. Shorter durations were therefore tested for non-inferiority.

OBJECTIVES

To establish whether or not 6 months' adjuvant trastuzumab is non-inferior to 12 months' in the treatment of HER2-positive early breast cancer using a primary end point of 4-year disease-free survival.

DESIGN

This was a Phase III randomised controlled non-inferiority trial.

SETTING

The setting was 152 NHS hospitals.

PARTICIPANTS

A total of 4088 patients with HER2-positive early breast cancer who it was planned would receive both chemotherapy and trastuzumab took part.

INTERVENTION

Randomisation (1 : 1) to 6 months' or 12 months' trastuzumab treatment.

MAIN OUTCOMES

The primary end point was disease-free survival. The secondary end points were overall survival, cost-effectiveness and cardiac function during treatment with trastuzumab. Assuming a 4-year disease-free survival rate of 80% with 12 months' trastuzumab, 4000 patients were required to demonstrate non-inferiority of 6 months' trastuzumab (5% one-sided significance, 85% power), defining the non-inferiority limit as no worse than 3% below the standard arm. Costs and quality-adjusted life-years were estimated using a within-trial analysis and a lifetime decision-analytic model.

RESULTS

Between 4 October 2007 and 31 July 2015, 2045 patients were randomised to 12 months' trastuzumab and 2043 were randomised to 6 months' trastuzumab. Sixty-nine per cent of patients had ER-positive disease; 90% received anthracyclines (49% with taxanes; 41% without taxanes); 10% received taxanes without anthracyclines; 54% received trastuzumab sequentially after chemotherapy; and 85% received adjuvant chemotherapy (58% were node negative). At 6.1 years' median follow-up, with 389 (10%) deaths and 566 (14%) disease-free survival events, the 4-year disease-free survival rates for the 4088 patients were 89.5% (95% confidence interval 88.1% to 90.8%) in the 6-month group and 90.3% (95% confidence interval 88.9% to 91.5%) in the 12-month group (hazard ratio 1.10, 90% confidence interval 0.96 to 1.26; non-inferiority p = 0.01), demonstrating non-inferiority of 6 months' trastuzumab. Congruent results were found for overall survival (non-inferiority p = 0.0003) and landmark analyses 6 months from starting trastuzumab [non-inferiority p = 0.03 (disease-free-survival) and p = 0.006 (overall survival)]. Six months' trastuzumab resulted in fewer patients reporting adverse events of severe grade [365/1929 (19%) vs. 460/1935 (24%) for 12-month patients; p = 0.0003] or stopping early because of cardiotoxicity [61/1977 (3%) vs. 146/1941 (8%) for 12-month patients; p < 0.0001]. Health economic analysis showed that 6 months' trastuzumab resulted in significantly lower lifetime costs than and similar lifetime quality-adjusted life-years to 12 months' trastuzumab, and thus there is a high probability that 6 months' trastuzumab is cost-effective compared with 12 months' trastuzumab. Patient-reported experiences in the trial highlighted fatigue and aches and pains most frequently.

LIMITATIONS

The type of chemotherapy and timing of trastuzumab changed during the recruitment phase of the study as standard practice altered.

CONCLUSIONS

PERSEPHONE demonstrated that, in the treatment of HER2-positive early breast cancer, 6 months' adjuvant trastuzumab is non-inferior to 12 months'. Six months' treatment resulted in significantly less cardiac toxicity and fewer severe adverse events.

FUTURE WORK

Ongoing translational work investigates patient and tumour genetic determinants of toxicity, and trastuzumab efficacy. An individual patient data meta-analysis with PHARE and other trastuzumab duration trials is planned.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN52968807, EudraCT 2006-007018-39 and ClinicalTrials.gov NCT00712140.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 40. See the NIHR Journals Library website for further project information.

Cost-effectiveness of six months versus 1-year adjuvant trastuzumab in HER2 positive early breast cancer in Egypt

Introduction: Breast cancer is the most prevalent cancer among women in Egypt. Trastuzumab is administered with chemotherapy for patients with HER2-positive advanced breast cancer (HER2 + ve ABC) in the metastatic and adjuvant settings resulting in improved treatment outcomes, and long-term follow-up. Some studies have evaluated whether equivalent outcomes can be achieved with reduced treatment duration. This study evaluates the cost-effectiveness of 6-month versus 1-year trastuzumab treatments from payer perspective over a 10 year time horizon.Methods: A half-cycle corrected Markov model was developed with five mutually exclusive health states; patient with HER2 +ve ABC, disease-free survival (DFS), local or regional relapse, metastatic relapse, and death. A cycle length of 6 months was applied, direct medical costs including cost of treatments, day-care, surgery, health states and follow-up visits were collected, and indirect costs such as lost productivity were not estimated. The transition probabilities and utilities were extracted from published literature, and deterministic sensitivity analyses were conducted.Results: Among the HER2 +ve ABC patient population in Egypt, the total QALYs of the 6-month trastuzumab were estimated to be 2.99 compared with 2.93 for the 1-year trastuzumab which resulted in a difference of 0.06 QALYs. The total costs were EGP 271,647 ($106,947) and EGP 381,248 ($150,097), respectively. These costs yielded an ICER of -109,600 EGP/QALY (-43,149 $/QALY) for the 6-month trastuzumab. The 6-month trastuzumab is a dominant strategy when compared to 1-year trastuzumab, resulting in improved effectiveness at a reduced cost. All analyses results confirmed the dominance of 6-month trastuzumab and our model robustness.Conclusions: This study concluded that 6-month trastuzumab is a cost-effective option when compared to 1-year trastuzumab in patients with HER2 +ve ABC in Egypt. Our findings provide health care decision makers with additional insights to best allocate available resources concurrently with the improvement of the Egyptian patient's outcomes.

Six Months vs. 12 Months of Adjuvant Trastuzumab Among Women With HER2-Positive Early-Stage Breast Cancer: A Meta-Analysis of Randomized Controlled Trials

Purpose: Both 12 and 6 months of trastuzumab in combination with chemotherapy are effective for HER2+ early-stage breast cancer. This meta-analysis was performed to assess the effectiveness and the toxicity of the two durations. Methods and Materials: We acquired relevant randomized controlled trials (RCTs) from PubMed, the Cochrane Library, ScienceDirect, EMBASE, Ovid MEDLINE, Web of Science, Scopus, and Google Scholar. Our endpoints included disease-free survival (DFS), overall survival (OS), number of recurrences, mortality and early stopping of trastuzumab, and adverse events (AEs). Results: We included five good-quality studies. Both durations of trastuzumab were effective among women with HER2+ early-stage breast cancer, but 12 months of trastuzumab appeared to have better DFS [hazard ratio (HR) = 1.10, 95% confidence interval (CI): 0.99-1.23, P = 0.09] and better OS than 6 months of trastuzumab (HR = 1.14, 95% CI: 0.99-1.32, P = 0.07). However, the 12 month group had more AEs, especially cardiac events [risk ratio (RR) = 0.66, 95% CI: 0.56-0.77, P < 0.00001]. In our sub-analyses, the 12 months duration had better DFS among patients using trastuzumab concurrently than the 6 months duration (HR = 1.23, 95% CI: 1.06-1.44, P = 0.006). Additionally, the 12 months duration had superior OS in women with ER-negative breast cancer (HR = 1.51, 95% CI: 1.10-2.08, P = 0.01) and patients treated with trastuzumab concurrently than the 6 months duration (HR = 1.61, 95% CI: 1.13-2.29, P = 0.008). Conclusions: Twelve months was the standard duration of adjuvant trastuzumab among patients with HER2+ early-stage breast cancer, with a tendency toward superior survival. However, patients in the 12 month group had more significant cardiac toxicity than those in the 6 month group.

Cardiotoxicity of trastuzumab given for 12 months compared to shorter treatment periods: a systematic review and meta-analysis of six clinical trials

BACKGROUND

Treatment de-escalation in early-stage, human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) has been attempted in order to decrease costs and toxicities. One of the strategies pursued is decreasing trastuzumab treatment duration, with mixed results thus far. Trastuzumab-associated cardiotoxicity, however, may be more frequent with 12 months of trastuzumab compared with shorter treatment lengths. Therefore, we have conducted a meta-analysis to address this question.

MATERIALS AND METHODS

A meta-analysis of trials testing 12 months of adjuvant trastuzumab versus shorter regimens, reporting cardiac outcomes in patients with HER2-positive BC was performed with the random effects model with inverse variance weighting.

RESULTS

Clinical cardiac dysfunction associated with 12 months of trastuzumab versus shorter trastuzumab regimens, including 11 250 patients, showed a pooled OR (pOR) of 1.90 (95% CI 1.37 to 2.64; p value <0.001; I2=65.7%); in the subgroup comparison of 12 versus 6 months, the pOR was 1.57 (95% CI 1.30 to 1.90; p<0.001; I2=5.7%). pOR for low left ventricular ejection fraction was 1.45 (95% CI 1.19 to 1.75; p<0.001; I2=11.9%), 1.55 (95% CI 1.00 to 2.42; p=0.052; I2=0.0%) for congestive heart failure and 3.70 (95% CI 0.27 to 51.60; p=0.33; I2=78.8%) for premature trastuzumab discontinuation due to cardiotoxicity for 12 months versus shorter trastuzumab regimens. Funnel plot analyses indicated a low risk of publication bias.

CONCLUSIONS

Compared to shorter treatment durations, there is sufficient evidence that 12 months of trastuzumab yields higher odds for the occurrence of relevant cardiac events. An individual patient-level data meta-analysis is needed in order to provide adequate data on risk factors for cardiotoxicity.

Effect of Adjuvant Trastuzumab for a Duration of 9 Weeks vs 1 Year With Concomitant Chemotherapy for Early Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer: The SOLD Randomized Clinical Trial

Importance

Trastuzumab plus chemotherapy is the standard adjuvant treatment for patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer. While the standard duration of trastuzumab treatment is 12 months, the benefits and harms of trastuzumab continued beyond the chemotherapy are unclear.

Objective

To evaluate the efficacy and safety of adjuvant trastuzumab continued beyond chemotherapy in women treated with up-front chemotherapy containing a taxane and trastuzumab.

Design, Setting, and Participants

Open-label, randomized (1:1) clinical trial including women with HER2-positive breast cancer. Chemotherapy was identical in the 2 groups, consisting of 3 cycles of 3-weekly docetaxel (either 80 or 100 mg/m2) plus trastuzumab for 9 weeks, followed by 3 cycles of fluorouracil, epirubicin, and cyclophosphamide. Thereafter, no trastuzumab was administered in the 9-week group, whereas controls received trastuzumab to complete 1 year of administration. Disease-free survival (DFS) was compared between the groups using a Cox model and the noninferiority approach. The estimated sample size was 2168 patients (1-sided testing, with a relative noninferiority margin of 1.3). From January 3, 2008, to December 16, 2014, 2176 patients were accrued from 7 countries.

Intervention

Docetaxel plus trastuzumab for 9 weeks, followed by 3 cycles of fluorouracil, epirubicin, and cyclophosphamide in both groups. Controls continued trastuzumab to 1 year.

Main Outcomes and Measures

The primary objective was DFS; secondary objectives included distant disease-free survival, overall survival, cardiac DFS, and safety.

Results

In the 2174 women analyzed, median age was 56 (interquartile range [IQR], 48-64) years. The median follow-up was 5.2 (IQR, 3.8-6.7) years. Noninferiority of the 9-week treatment could not be demonstrated for DFS (hazard ratio, 1.39; 2-sided 90% CI, 1.12-1.72). Distant disease-free survival and overall survival did not differ substantially between the groups. Thirty-six (3%) and 21 (2%) patients in the 1-year and the 9-week groups, respectively, had cardiac failure; the left ventricle ejection fraction was better maintained in the 9-week group. An interaction was detected between the docetaxel dose and DFS; patients in the 9-week group treated with 80 mg/m2 had inferior and those treated with 100 mg/m2 had similar DFS as patients in the 1-year group.

Conclusions and Relevance

Nine weeks of trastuzumab was not noninferior to 1 year of trastuzumab when given with similar chemotherapy. Cardiac safety was better in the 9-week group. The docetaxel dosing with trastuzumab requires further study.

Trial Registration

ClinicalTrials.gov Identifier: NCT00593697.

6 versus 12 months of adjuvant trastuzumab for HER2-positive early breast cancer (PERSEPHONE): 4-year disease-free survival results of a randomised phase 3 non-inferiority trial

BACKGROUND

Adjuvant trastuzumab significantly improves outcomes for patients with HER2-positive early breast cancer. The standard treatment duration is 12 months but shorter treatment could provide similar efficacy while reducing toxicities and cost. We aimed to investigate whether 6-month adjuvant trastuzumab treatment is non-inferior to the standard 12-month treatment regarding disease-free survival.

METHODS

This study is an open-label, randomised phase 3 non-inferiority trial. Patients were recruited from 152 centres in the UK. We randomly assigned patients with HER2-positive early breast cancer, aged 18 years or older, and with a clear indication for chemotherapy, by a computerised minimisation process (1:1), to receive either 6-month or 12-month trastuzumab delivered every 3 weeks intravenously (loading dose of 8 mg/kg followed by maintenance doses of 6 mg/kg) or subcutaneously (600 mg), given in combination with chemotherapy (concurrently or sequentially). The primary endpoint was disease-free survival, analysed by intention to treat, with a non-inferiority margin of 3% for 4-year disease-free survival. Safety was analysed in all patients who received trastuzumab. This trial is registered with EudraCT (number 2006-007018-39), ISRCTN (number 52968807), and ClinicalTrials.gov (number NCT00712140).

FINDINGS

Between Oct 4, 2007, and July 31, 2015, 2045 patients were assigned to 12-month trastuzumab treatment and 2044 to 6-month treatment (one patient was excluded because they were double randomised). Median follow-up was 5·4 years (IQR 3·6-6·7) for both treatment groups, during which a disease-free survival event occurred in 265 (13%) of 2043 patients in the 6-month group and 247 (12%) of 2045 patients in the 12-month group. 4-year disease-free survival was 89·4% (95% CI 87·9-90·7) in the 6-month group and 89·8% (88·3-91·1) in the 12-month group (hazard ratio 1·07 [90% CI 0·93-1·24], non-inferiority p=0·011), showing non-inferiority of the 6-month treatment. 6-month trastuzumab treatment resulted in fewer patients reporting severe adverse events (373 [19%] of 1939 patients vs 459 [24%] of 1894 patients, p=0·0002) or stopping early because of cardiotoxicity (61 [3%] of 1939 patients vs 146 [8%] of 1894 patients, p<0·0001).

INTERPRETATION

We have shown that 6-month trastuzumab treatment is non-inferior to 12-month treatment in patients with HER2-positive early breast cancer, with less cardiotoxicity and fewer severe adverse events. These results support consideration of reduced duration trastuzumab for women at similar risk of recurrence as to those included in the trial.

FUNDING

UK National Institute for Health Research, Health Technology Assessment Programme.

Deescalating Adjuvant Trastuzumab in HER2-Positive Early-Stage Breast Cancer: A Systemic Review and Meta-Analysis

Background

One year of adjuvant trastuzumab in combination with chemotherapy is the standard of care in early-stage human epidermal growth factor receptor 2 (HER2)-positive breast cancer. Existing data on shortening trastuzumab treatment show conflicting results.

Methods

A search of PubMed and abstracts from key conferences identified randomized trials that compared abbreviated trastuzumab therapy to 1 year of treatment in early-stage HER2-positive breast cancer. Hazard ratios (HRs) and 95% confidence intervals (CIs) were extracted for disease-free survival (DFS) and overall survival (OS). Subgroup analyses evaluated the effect of nodal involvement, estrogen receptor expression, and the duration of abbreviated trastuzumab (9–12 weeks vs 6 months). Odds ratios (ORs) and 95% confidence intervals were computed for prespecified cardiotoxicity events including cardiac dysfunction and congestive heart failure. P values were two-sided.

Results

Analysis included six trials comprising 11 603 patients. Shorter trastuzumab treatment was associated with worse DFS (HR = 1.14, 95% CI = 1.05 to 1.25, P  = .002) and OS (HR = 1.15, 95% CI = 1.02 to 1.29. P = .02). The effect on DFS was not influenced by estrogen receptor status (P for the subgroup difference = .23), nodal involvement (P = .44), or the different duration of trastuzumab in the experimental arm (P = .09). Shorter trastuzumab treatment was associated with lower odds of cardiac dysfunction (OR = 0.67, 95% CI = 0.55 to 0.81, P < .001) and congestive heart failure (OR = 0.66, 95% CI = 0.50 to 0.86, P = .003).

Conclusions

Compared with 1 year, shorter duration of adjuvant trastuzumab is associated with statistically significantly worse DFS and OS despite favorable cardiotoxicity profile. One year of targeted HER2 treatment should remain the standard adjuvant treatment in early-stage HER2-positive disease with appropriate cardiac monitoring.

Disease-free survival as a surrogate for overall survival in patients with HER2-positive, early breast cancer in trials of adjuvant trastuzumab for up to 1 year: a systematic review and meta-analysis

BACKGROUND

Although frequently used as a primary endpoint, disease-free survival has not been validated as a surrogate for overall survival in early breast cancer. We investigated this surrogacy in the adjuvant setting of treatment with anti-HER2 antibodies.

METHODS

In a systematic review and meta-analysis, we identified published and non-published randomised controlled trials with completed accrual and available disease-free survival and overall survival results for the intention-to-treat population as of September 2016. Bibliographic databases (MEDLINE, Embase, and Cochrane Central Register of Controlled Trials), clinical trial registries (Clinicaltrials.gov, EU Clinical Trials Register, WHO International Clinical Trials Registry Platform, and PharmNet.Bund), and trial registries from relevant pharmaceutical companies were searched. Eligibility for treatment of HER2-positive early breast cancer required at least one group to have an anti-HER antibody treatment (ie, trastuzumab, pertuzumab, or trastuzumab emtansine) planned for 12 months, and at least one control arm with chemotherapy without the antibody, a lower total dose or duration of the antibody, or observation alone. Units of analysis were contrasts: two-group trials gave rise to one contrast, whereas trials with more than two groups gave rise to more than one contrast. We excluded trials enrolling patients with recurrent, metastatic, or non-invasive disease, and those testing neoadjuvant therapy exclusively. Our primary objective was to estimate patient-level and trial-level correlations between disease-free survival and overall survival. We measured the association between disease-free survival and overall survival using Spearman's correlation coefficient (rs), and the association between hazard ratios (HRs) for disease-free survival and overall survival using R2. We computed the surrogate threshold effect, the maximum HR for disease-free survival that statistically predicts an HR for overall survival less than 1·00 in a future trial.

FINDINGS

Eight trials (n=21 480 patients) gave rise to a full set (12 contrasts). Patient-level associations between disease-free and overall survival were strong (rs=0·90 [95% CI 0·89-0·90]). Trial-level associations gave rise to values of R2 of 0·75 (95% CI 0·50-1·00) for the full set. Subgroups defined by nodal status and hormone receptor status yielded qualitatively similar results. Depending on the expected number of deaths in a future trial, the surrogate threshold effects ranged from 0·56 to 0·81, based on the full set.

INTERPRETATION

These findings suggest that it is appropriate to continue to use disease-free survival as a surrogate for overall survival in trials in HER-2-positive, early breast cancer. The key limitation of this study is the dependence of its results on the trials included and on the existence of an outlying trial.

FUNDING

Roche Pharma AG.

Short-duration versus 1-year adjuvant trastuzumab in early HER2 positive breast cancer: A meta-analysis of randomized controlled trials

BACKGROUND

One year of adjuvant trastuzumab treatment is the standard of care for early stage human epidermal growth factor receptor 2 (HER2)-positive breast cancer patients; however, controversy remains regarding the optimal schedule of trastuzumab because the selection of the 1-year schedule was arbitrary. After the remarkable results of the PERSEPHONE trial as well as the updated final results of the PHARE trial, we performed an updated meta-analysis to reassess the efficacy and safety of shorter durations of trastuzumab.

METHODS

A literature search of databases was conducted to identify randomized controlled trials reporting the efficacy and cardiotoxicity of shorter-duration and standard 1-year trastuzumab treatment. The hazard ratios (HRs) of disease-free survival (DFS) and overall survival (OS), and the odds ratios (ORs) of cardiac events were also estimated and pooled.

RESULTS

Six studies were eligible, including a total of 11,496 patients. Both DFS (HR = 1.13; 95% confidence interval [CI] = 1.03-1.25; p = 0.01) and OS (HR = 1.16; 95% CI = 1.01-1.32; p = 0.03) were significantly improved with conventional 1-year trastuzumab treatment compared with shorter treatments. The more pronounced survival benefits observed in patients with negative estrogen receptor (ER) tumor and nodal involvement should be interpreted cautiously because of the lack of interaction between the survival benefit and ER, as well as the nodal status (interaction test, ER status: p = 0.26; nodal status: p = 0.60). One year of trastuzumab treatment resulted in a substantial DFS benefit compared with shorter schedules when administered concurrently with chemotherapy (HR = 1.22; 95% CI = 1.09-1.38; p = 0.0008; p = 0.02 for the interaction test). Patients in the shorter duration group experienced significantly fewer cardiac events (OR = 0.52; 95% CI = 0.43-0.62; p < 0.00001).

CONCLUSIONS

Though correlated with an increasing risk of cardiotoxicity, 1 year of adjuvant trastuzumab treatment conferred substantial survival benefits and should remain as the preferred treatment for early stage HER2-positive breast cancer. Shorter durations of trastuzumab may serve as an alternative choice for patients with cardiac disease and those at lower risk of recurrence.

A clinical perspective on escalating or de-escalating adjuvant therapy in HER2+ breast cancer

Introduction: Patients with early HER2-positive breast cancer (BC) benefit from HER2-targeted systemic therapy. The endorsed standard adjuvant treatment for patients with early HER2-positive breast cancer is chemotherapy plus trastuzumab administered for 1 year. Areas covered: Several trials have investigated modifications of the standard treatment in terms of de-escalation by either shortening the duration or giving less resource-demanding regimens and in terms of escalation by either adding a second anti-HER2 agent or extending the duration of HER2-targeted treatment for more than 12 months. In this perspective, we would offer a comprehensive view of these trials and discuss their findings. Expert commentary: At the current state of knowledge, there are still open questions regarding the management of HER2+ BC patients, such as the most adequate duration of trastuzumab therapy, the optimal chemotherapy regimen that should be combined with trastuzumab, and the addition of a second anti-HER2 agent. Growing evidences suggest that some HER2+ BC patients may not need chemotherapy. If these patients could be recognized upfront, optimal response could potentially be reached with HER2-targeted therapy alone.

Herceptin® (trastuzumab) in HER2-positive early breast cancer: a systematic review and cumulative network meta-analysis

BACKGROUND

Originator trastuzumab (Herceptin®; H) is an antibody-targeted therapy to treat patients with human epidermal growth factor receptor 2-positive (HER2+) early breast cancer (EBC). We investigated the overall survival (OS) advantage conferred by the addition of H to chemotherapy for HER2+ EBC patients and how the OS advantage changed over time.

METHODS

A systematic literature review (SLR) identified randomized controlled trials (RCTs) and non-randomized studies (NRSs) published from January 1, 1990 to January 19, 2017, comparing systemic therapies used in the neoadjuvant/adjuvant settings to treat HER2+ EBC patients. Bayesian cumulative network meta-analyses (cNMAs) of OS were conducted to assess the published literature over time. Heterogeneity was assessed through sensitivity and subgroup analyses.

RESULTS

The SLR identified 31 unique studies (28 RCTs, 3 NRSs) included in the OS analyses from 2008 to 2016. In the reference case cNMA (RCTs alone), initial evidence demonstrated an OS advantage for H/chemotherapy compared with chemotherapy alone in HER2+ EBC patients. As additional OS data were published, the precision around this survival benefit strengthened over time. Both H/anthracycline-containing chemotherapy and H/non-anthracycline-containing chemotherapy regimens provided similar OS advantages for HER2+ EBC patients.

CONCLUSION

This analysis represents the most comprehensive SLR/cNMA to date of published OS data in HER2+ EBC studies. These findings demonstrate why H/chemotherapy is now the established standard of care in HER2+ EBC. In the case of H, the benefits of early patient access far outweighed the risk of waiting for more precise information.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017055763.

Optimizing (neo)adjuvant treatment of HER2-positive breast cancer

The development of human epidermal growth factor 2 (HER2)-directed therapy has resulted in significant improvement in outcomes for patients with early-stage HER2-overexpressing (HER2+) breast cancer. In recent years, newer HER2-directed agents and novel treatment strategies have been developed with ongoing improvements in overall outcomes. However, with the addition of newer agents, there is an increasing need to risk stratify patients to maximize efficacy and minimize toxicity of treatment. De-escalation of therapy with the potential to shorten the duration of adjuvant therapy and minimize chemotherapy administration in patients with favorable disease can be considered. On the other hand, escalation of therapy with the addition of novel HER2-directed agents and extended duration of therapy in patients at high risk of relapse can help improve long-term cure rates. Herein, we discuss recent developments in neoadjuvant and adjuvant strategies for the treatment of potentially curable HER2+ breast cancer.

Effectiveness of trastuzumab as adjuvant therapy in patients with early stage breast cancer: A systematic review and meta-analysis

Background: Trastuzumab in combination with chemotherapy has long been established as a standard treatment for HER2-positive patients in early stage breast cancer (BC). The present study aimed at assessing the effectiveness of trastuzumab adjuvant therapy in early stage BC in overall survival (OS) and disease-free survival (DFS). Methods: A systematic review and meta-analysis was performed to evaluate the effectiveness of trastuzumab adjuvant therapy. PubMed, Cochrane library, Scopus, Web of Science, and Embase databases were searched for relevant RCTs from the beginning to February 2017. Quality assessment of studies was conducted using the Cochrane Risk of Bias Tool. The desired outcomes were OS and DFS. Results: A total of 1818 articles were identified first, however, only 11 studies were eligible to be included in this study. Our findings and meta-analysis results revealed that trastuzumab is effective in increasing OS (OS hazard ratio: -0.286 ± 0.049, 95%CI (-0.381, - 0.191)) and improving DFS (DFS hazard ratio: -0.419± 0.077, 95%CI (-0.569, -0.269)). The most serious but negligible side effect of trastuzumab is congestive heart failure. Conclusion: Adding trastuzumab as adjuvant therapy in early stages of BC in HER2 positive patients could increase OS and DFS of the patients effectively.

Suberoylanilide hydroxamic acid sensitizes neuroblastoma to paclitaxel by inhibiting thioredoxin-related protein 14-mediated autophagy

Paclitaxel is not as effective for neuroblastoma as most of the front‐line chemotherapeutics due to drug resistance. This study explored the regulatory mechanism of paclitaxel‐associated autophagy and potential solutions to paclitaxel resistance in neuroblastoma. The formation of autophagic vesicles was detected by scanning transmission electron microscopy and flow cytometry. The autophagy‐associated proteins were assessed by western blot. Autophagy was induced and the autophagy‐associated proteins LC3‐I, LC3‐II, Beclin 1, and thioredoxin‐related protein 14 (TRP14), were found to be upregulated in neuroblastoma cells that were exposed to paclitaxel. The inhibition of Beclin 1 or TRP14 by siRNA increased the sensitivity of the tumor cells to paclitaxel. In addition, Beclin 1‐mediated autophagy was regulated by TRP14. Furthermore, the TRP14 inhibitor suberoylanilide hydroxamic acid (SAHA) downregulated paclitaxel‐induced autophagy and enhanced the anticancer effects of paclitaxel in normal control cancer cells but not in cells with upregulated Beclin 1 and TRP14 expression. Our findings showed that paclitaxel‐induced autophagy in neuroblastoma cells was regulated by TRP14 and that SAHA could sensitize neuroblastoma cells to paclitaxel by specifically inhibiting TRP14.

Multi-arm Cost-Effectiveness Analysis (CEA) comparing different durations of adjuvant trastuzumab in early breast cancer, from the English NHS payer perspective

BACKGROUND

Trastuzumab improves survival in HER2+ breast cancer patients, with some evidence of adverse cardiac side effects. Current recommendations are to give adjuvant trastuzumab for one year or until recurrence, although trastuzumab treatment for only 9 or 10 weeks has shown similar survival rates to 12-month treatment. We present here a multi-arm joint analysis examining the relative cost-effectiveness of different durations of adjuvant trastuzumab.

METHODS AND FINDINGS

Network meta-analysis (NMA) was used to examine which trials' data to include in the cost-effectiveness analysis (CEA). A network using FinHer (9 weeks vs. zero) and BCIRG006 (12 months vs. zero) trials offered the only jointly randomisable network so these trials were used in the CEA. The 3-arm CEA compared costs and quality-adjusted life-years (QALYs) associated with zero, 9-week and 12-month adjuvant trastuzumab durations in early breast cancer, using a decision tree followed by a Markov model that extrapolated the results to a lifetime time horizon. Pairwise incremental cost-effectiveness ratios (ICERs) were also calculated for each pair of regimens and used in budget impact analysis, and the Bucher method was used to check face validity of the findings. Addition of the PHARE trial (6 months vs. 12 months) to the network, in order to create a 4-arm CEA including the 6-month regimen, was not possible as late randomisation in this trial resulted in recruitment of a different patient population as evidenced by the NMA findings. The CEA results suggest that 9 weeks' trastuzumab is cost-saving and leads to more QALYs than 12 months', i.e. the former dominates the latter. The cost-effectiveness acceptability frontier (CEAF) favours zero trastuzumab at willingness-to-pay levels below £2,500/QALY and treatment for 9 weeks above this threshold. The combination of the NMA and Bucher investigations suggests that the 9-week duration is as efficacious as the 12-month duration for distant-disease-free survival and overall survival, and safer in terms of fewer adverse cardiac events.

CONCLUSIONS

Our CEA results suggest that 9-week trastuzumab dominates 12-month trastuzumab in cost-effectiveness terms at conventional thresholds of willingness to pay for a QALY, and the 9-week regimen is also suggested to be as clinically effective as the 12-month regimen according to the NMA and Bucher analyses. This finding agrees with the results of the E2198 head-to-head study that compared 10 weeks' with 14 months' trastuzumab and found no significant difference. Appropriate trial design and reporting is critical if results are to be synthesisable with existing evidence, as selection bias can lead to recruitment of a different patient population from existing trials. Our analysis was not based on head-to-head trials' data, so the results should be viewed with caution. Short-duration trials would benefit from recruiting larger numbers of participants to reduce uncertainty in the synthesised results.

Escalating and de-escalating treatment in HER2-positive early breast cancer

The current standard adjuvant systemic treatment of early HER2-positive breast cancer consists of chemotherapy plus 12months of trastuzumab, with or without endocrine therapy. Several trials have investigated modifications of the standard treatment that are shorter and less resource-demanding (de-escalation) or regimens that aim at dual HER2 inhibition or include longer than 12months of HER2-targeted treatment (escalation). Seven randomized trials investigate shorter than 12months of trastuzumab treatment duration. The shorter durations were not statistically inferior to the 1-year duration in the 3 trials with survival results available, but 2 of the trials were small and 1 had a relatively short follow-up time of the patients at the time of reporting. The pathological complete response (pCR) rates were numerically higher in all 9 randomized trials that compared chemotherapy plus dual HER2 inhibition consisting of trastuzumab plus either lapatinib, neratinib, or pertuzumab with chemotherapy plus trastuzumab as neoadjuvant treatments, but the superiority of chemotherapy plus dual HER2-inhibition over chemotherapy plus trastuzumab remains to be demonstrated in the adjuvant setting. One year of adjuvant trastuzumab was as effective as 2years of trastuzumab in the HERA trial, and was associated with fewer side-effects. Extending 1-year adjuvant trastuzumab treatment with 1year of neratinib improved disease-free survival in the ExteNET trial, but the patient follow-up times are still short, and no overall survival benefit was reported. Several important trials are expected to report results in the near future and may modify the current standard.

Extended anti-HER2 therapy in early breast cancer: longer beats shorter?

PURPOSE OF REVIEW

One-year duration of adjuvant trastuzumab is the gold standard since 2005. During the last decade many attempts have been made to both increase and reduce the treatment duration. The purpose of this article is to review the current available evidence regarding alternative anti-HER2 therapy durations in the (neo)adjuvant treatment of HER2-positive localized breast cancer patients.

RECENT FINDINGS

According to the majority of published data, shorter trastuzumab schedule has shown a decreased benefit in the overall HER2 population, whereas extending adjuvant trastuzumab, beyond 1 year, does not improve the outcome and is associated with increased cardiac toxicity. However, new challenging questions are raised by the recent results of ExteNet trial, in which sequential introduction of 1 year neratinib after standard trastumab-based therapy improved the outcome, especially in the estrogen receptor-positive subset of patients.

SUMMARY

To date the standard duration of adjuvant trastuzumab remains 1 year in the adjuvant setting. It is likely that ongoing trials will clarify which patients could benefit from a shorter or a longer treatment. Taking into account patient's specific risk/benefit ratio and new biomarkers, in future, a 'personalized' treatment duration would be warranted.