Demographic, tumor and clinical features of clinical trials versus clinical practice patients with HER2-positive early breast cancer: results of a prospective study

Optimizing treatment for HER2-positive HR-positive breast cancer

Triple-positive breast tumors overexpress human epidermal growth factor receptor 2 (HER2) and are positive for hormone receptor (HR) expression. Data from real-life and clinical trials show that estrogen receptor (ER) expression affects the response to combinations of anti-HER2 and associated systemic therapies. Despite triple-positive tumors having decreased response rates compared to HR-negative/HER2-positive breast cancers, optimizing anti-HER2 treatment with dual anti-HER2 blockade remains important for optimal disease control. Preclinical data on the cross-talk between ER and growth factor receptor pathways show the efficacy of combinations of endocrine therapy and anti-HER2 drugs, which is confirmed in the clinic. Molecular dissection of triple-positive breast cancer might provide the rational for additional therapeutic strategies and the identification of promising biomarkers. This review summarizes data on systemic treatment efficacy from major clinical trials and perspectives for future clinical research in triple-positive breast cancer.

Determinants of activity and efficacy of anti-PD1/PD-L1 therapy in patients with advanced solid tumors recruited in a clinical trials unit: a longitudinal prospective biomarker-based study

Immune-checkpoint inhibitors (ICI) have revolutionized the therapeutic landscape of cancer. However, optimal patient selection is still an unmet need. One-hundred-forty-six patients with metastatic cancer candidates to ICI at the Hospital Clinic of Barcelona Clinical Trials Unit were prospectively recruited in this observational study. Blood samples were collected at different timepoints, baseline LIPI score calculated and pre-ICI archived tissues retrieved to evaluate PD-L1, tumor-infiltrating lymphocytes (TILs) and PD1 mRNA levels. Tumor assessments were centrally reviewed by RECIST 1.1 criteria. Associations with overall response rates (ORR), durable clinical benefit (DCB), progression-free survival (PFS) and overall survival (OS) were performed with univariable/multivariable logistic and Cox regressions, where appropriate. At a median follow-up of 26.9 months, median PFS and OS were 2.7 and 12.9 months. Response rates were 17.8% with duration of response (DOR) of 4.4 months. LIPI score was independently associated with PFS (p = 0.025) and OS (p < 0.001). Immunotherapy-naïve status was independently associated with better PFS (p = 0.005). Time-to-best response (TTBR) and ORR (p < 0.001 both) were associated with better OS at univariate analysis. PFS and DOR were moderately correlated with OS (p < 0.001 both). A PD-L1 10% cut-off detected worse/best responders in terms of ORR (univariate p = 0.011, multivariate p = 0.028) and DCB (univariate p = 0.043). PD1 mRNA levels were strikingly associated to complete responses (p = 0.021). To resume, in our prospective observational pan-cancer study, baseline LIPI score, immunotherapy-naïve status, cancer type and RT before starting ICI were the most relevant clinical factors independently correlated with immunotherapy outcomes. Longer TTBR seemed to associate with better survival, while PD1 mRNA and PD-L1 protein levels might be tumor-agnostic predictive factors of response to ICI and should be furtherly explored.

The emerging role of real-world data in advanced breast cancer therapy: Recommendations for collaborative decision-making

Among stakeholders and decision-makers in advanced breast cancer, the demand for insights from real-world data (RWD) is increasing. Although RWD can be used to support decisions throughout different stages of a breast cancer drug's life cycle, barriers exist to its use and acceptance. We propose a collaborative approach to generating and using RWD that is meaningful to multiple stakeholders, and encourage frameworks toward international guidelines to help standardize RWD methodologies to achieve more efficient use of RWD insights.

Surrogate endpoints for early-stage breast cancer: a review of the state of the art, controversies, and future prospects

Drug approval for early-stage breast cancer (EBC) has been historically granted in the context of registration trials based on adequate outcomes such as disease-free survival and overall survival. Improvements in long-term outcomes have made it more difficult to demonstrate the clinical benefit of a new cancer drug in large, randomized, comparative clinical trials. Therefore, the use of surrogate endpoints rather than traditional measures allows for cancer drug trials to proceed with smaller sample sizes and shorter follow-up periods, which reduces drug development time. Among surrogate endpoints for breast cancer, the increase in pathological complete response (pCR) rates was considered appropriate for accelerated drug approval. The association between pCR and long-term outcomes was strongest in patients with aggressive tumor subtypes, such as triple-negative and human epidermal growth factor receptor 2 (HER2)-positive/hormone receptor-negative breast cancers. Whereas in hormone receptor-positive/HER2-negative EBC, the most accepted surrogate markers for endocrine therapy-based trials include changes in Ki67 and the preoperative endocrine prognostic index. Beyond the classic endpoints, further prognostic tools are required to provide EBC patients with individualized and effective therapies, and the neoadjuvant setting provides an excellent platform for drug development and biomarker discovery. Nowadays, the availability of multigene signatures is offering a standardized quantitative and reproducible tool to potentiate the efficacy of standard treatment for high-risk patients and develop de-escalated treatments for patients at lower risk of relapse. In this article, we first evaluate the surrogacies used for long-term outcomes and the underlying evidence supporting the use of each surrogate endpoint for the accelerated or regular drug approval process in EBC. Next, we provide an overview of the most recent studies and innovative strategies in a (neo)adjuvant setting as a platform to accelerate new drug approval. Finally, we highlight some clinical trials aimed at tailoring systemic treatment of EBC using prognosis-related factors or early biomarkers of drug sensitivity or resistance.

Demographic Characteristics and Treatment Patterns Among Patients Receiving Palbociclib for HR+/HER2- Advanced Breast Cancer: A Nationwide Real-World Experience

Background

This nationwide retrospective study reports data on the real-world use of the selective cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor palbociclib in a large population of advanced breast cancer (ABC) patients during a 2-year period in Hungary.

Methods

All patients with ABC who received palbociclib between May 1, 2017 and June 30, 2019 were included in the analysis. Patient demographic and clinical characteristics, disease-related factors and treatment patterns were examined during the early access program and in the regular reimbursement period.

Results

Altogether, 962 patients were included (mean age: 60.6 years). A total of 399 patients (41%) were treated with palbociclib plus aromatase inhibitors (P+AI), and 563 patients (59%) received palbociclib and fulvestrant (P+F). The most commonly prescribed AI was letrozole (n=359; 90%). Of those with metastatic disease (n=733; 76%), 241 patients (33%) had visceral metastases and 449 (61%) had bone-only disease. The majority of patients (79%) received palbociclib as first- or second-line therapy for ABC. The starting dose of palbociclib was 125 mg in 98% of patients; dose reductions were required in 32% of patients receiving P+AI and 31% of those treated with P+F. At the time of data collection, palbociclib therapy was ongoing in 270 patients (68%) in the P+AI group and 245 patients (44%) in the P+F group.

Conclusions

This nationwide analysis is the first to provide insights into the real-world use of palbociclib in a large patient population from a Central-Eastern European country. The findings confirm the good tolerability of palbociclib with similar dose reduction rates to those reported from registration trials.

T-DM1 versus pertuzumab, trastuzumab and a taxane as first-line therapy of early-relapsed HER2-positive metastatic breast cancer: an Italian multicenter observational study

Background

The current standard first-line treatment of human epidermal growth factor receptor 2 (HER2)-positive (+) metastatic breast cancer is the combination of pertuzumab, trastuzumab and a taxane (P + T + taxane), while standard second-line is ado-trastuzumab-emtansine (T-DM1). The registration trial of pertuzumab, however, did not include early-relapsing patients, defined as patients experiencing tumor relapse ≤12 months from the end of (neo)adjuvant anti-HER2 therapy. Conversely, the pivotal trial of T-DM1 included some patients relapsing ≤6 months after the end of (neo)adjuvant trastuzumab. Thus, a proportion of early-relapsing patients are currently eligible to receive T-DM1 as first-line treatment. Nevertheless, no direct comparison exists between the two regimens in this clinical setting.

Patients and methods

We retrospectively compared T-DM1 versus P + T + taxane as first-line treatment in two cohorts of early-relapsing patients in an Italian ‘real-world’ setting, involving 14 public health care institutions. The primary endpoint was progression-free survival. Secondary endpoints included patients' characterization, overall survival and post-progression survival. Univariate and multivariate analyses were carried out. All tests were two-sided and a P ≤ 0.05 was considered statistically significant.

Results

Among 1252 screened patients, 75 met the inclusion criteria. Forty-four (58.7%) received P + T + taxane and 31 (41.3%) received T-DM1. The two cohorts showed similar characteristics of aggressiveness and no significant differences in treatment history. T-DM1, compared with P + T + taxane was associated with worse progression-free survival (adjusted hazard ratio: 2.26, 95% confidence interval: 1.13-4.52, P = 0.021) and overall survival (adjusted hazard ratio: 3.95, 95% confidence interval: 1.38-11.32, P = 0.010), irrespective of previous (neo)adjuvant treatment, age, hormone receptors status, time-to-relapse (≤6 months or within 6-12 months) and presence of visceral/brain metastases. No differences were observed in post-progression survival (P = 0.095).

Conclusions

Our study suggests superiority for P + T + taxane over T-DM1 as up-front treatment of early-relapsing HER2+ metastatic breast cancer, which merits further assessment in larger and prospective trials.

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This is the first study comparing pertuzumab + trastuzumab + taxane (P + T + taxane) with T-DM1 in early-relapsing HER2+ MBC.

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The majority of early-relapsing HER2+ MBC have high-grade, node-positive, large primary tumors.

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First-line T-DM1 compared with P + T + taxane is associated with worse progression-free survival.

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First-line T-DM1 compared with P + T + taxane is associated with worse overall survival.

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Post-progression survival does not differ between the two treatments cohorts.

Validation of the AJCC prognostic stage for HER2-positive breast cancer in the ShortHER trial

BACKGROUND

The 8th edition of the American Joint Committee on Cancer (AJCC) staging has introduced prognostic stage based on anatomic stage combined with biologic factors. We aimed to validate the prognostic stage in HER2-positive breast cancer patients enrolled in the ShortHER trial.

METHODS

The ShortHER trial randomized 1253 HER2-positive patients to 9 weeks or 1 year of adjuvant trastuzumab combined with chemotherapy. Patients were classified according to the anatomic and the prognostic stage. Distant disease-free survival (DDFS) was calculated from randomization to distant relapse or death.

RESULTS

A total of 1244 patients were included. Compared to anatomic stage, the prognostic stage downstaged 41.6% (n = 517) of patients to a more favorable stage category. Five-year DDFS based on anatomic stage was as follows: IA 96.6%, IB 94.1%, IIA 92.4%, IIB 87.3%, IIIA 81.3%, IIIC 70.5% (P < 0.001). Five-year DDFS according to prognostic stage was as follows: IA 95.7%, IB 91.4%, IIA 86.9%, IIB 85.0%, IIIA 77.6%, IIIC 67.7% (P < 0.001). The C index was similar (0.69209 and 0.69249, P = 0.975). Within anatomic stage I, the outcome was similar for patients treated with 9 weeks or 1 year trastuzumab (5-year DDFS 96.2% and 96.6%, P = 0.856). Within prognostic stage I, the outcome was numerically worse for patients treated with 9 weeks trastuzumab (5-year DDFS 93.7% and 96.3%, P = 0.080).

CONCLUSIONS

The prognostic stage downstaged 41.6% of patients, while maintaining a similar prognostic performance as the anatomic stage. The prognostic stage is valuable in counseling patients and may serve as reference for a clinical trial design. Our data do not support prognostic stage as guidance to de-escalate treatment.

TRIAL REGISTRATION

EUDRACT number: 2007-004326-25; NCI ClinicalTrials.gov number: NCT00629278.

Treatment patterns and survival in HER2-positive early breast cancer: a whole-of-population Australian cohort study (2007-2016)

Background

Randomised clinical trials (RCTs) demonstrate that trastuzumab improves survival in patients with human epidermal growth factor 2-positive early breast cancer (HER2 + EBC), but real-world patients and clinical practice often differ from RCTs. We examine real-world treatment patterns and outcomes associated with trastuzumab for HER2 + EBC.

Methods

We identified all Australians dispensed trastuzumab for HER2 + EBC between 1/1/2007 and 30/6/2016. We estimated the proportion of patients completing 12 months of treatment (defined as ≥350 days of exposure within 540 days of initiation). We estimated overall survival (OS) and recurrence-free survival (RFS) by using trastuzumab dispensing for metastatic breast cancer as a surrogate for recurrence.

Results

Our study included 14,644 patients. Among patients with ≥540 days of follow-up (n = 11,903), 67.4% completed 12 months of trastuzumab. OS rates at 5 and 9 years were 92.7 and 87.9%, and RFS rates at 5 and 9 years were 86.8 and 81.4%, respectively. Patients who completed 12 months of trastuzumab had a 9-year OS rate of 90.2% compared with 86.2% among patients receiving <12 months of therapy (adjusted HR 0.71, 95% CI 0.62–0.81).

Conclusions

Real-world HER2 + EBC patients are less likely to complete 12 months of trastuzumab than some clinical trial counterparts but have survival outcomes comparable to those reported in landmark RCTs.

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.

Pertuzumab, trastuzumab and taxane-based treatment for visceral organ metastatic, trastuzumab-naïve breast cancer: real-life practice outcomes

PURPOSE

In this study, we aimed to describe the real-life practice outcomes of pertuzumab-trastuzumab-taxane (PTT) combination in visceral organ metastatic, trastuzumab-naive breast cancer (BC) patients.

METHODS

This study was conducted by Turkish Oncology Group and included 317 patients' data from 36 centers.

RESULTS

Median age was 51 (22-82). Median PFS was 28.5 months, while median OS was 40.3 months. Patients with brain metastases (n: 13, 4.1%) had worse PFS (16.8 m vs. 28.5 m; p = 0.002) and OS (26.7 m vs. 40.3 m; p = 0.009). Patients older than 65 years of age (n: 42, 13.2%) had significantly lower OS results (19.8 m vs. 40.3 m; p = 0.01). Two hundred sixty-eight patients (86.7%) received docetaxel while 37 patients (11.7%) received paclitaxel. PFS and OS were similar between taxane groups. In eight patients (2.5%), 5-40% ejection fraction decrement from baseline was detected without any clinical sign of heart failure.

CONCLUSIONS

Our RLP trial included only visceral metastatic, trastuzumab-naïve BC patients including cases with brain involvement who received PTT combination in the first-line treatment. Regardless of negative prognostic characteristics, our results are in parallel with pivotal trial. Further strategies for brain metastasis should be developed to improve outcomes despite encouraging results with PTT treatment. Taxane selection can be personalized and endocrine maintenance may further improve outcomes after taxanes were discontinued. To our knowledge, this is the largest scale real-life clinical practice study of pertuzumab-trastuzumab-taxane therapy to date.

Human epidermal growth factor receptor 2 dual blockade with trastuzumab and pertuzumab in real life: Italian clinical practice versus the CLEOPATRA trial results

OBJECTIVES

Given their inclusion and exclusion criteria, randomized clinical trials (RCT) might not include a population that truly mirrors real life (RL). This raises concerns about the applicability of RCT results in clinical practice. We evaluated the efficacy of anti-HER2 treatment with pertuzumab combined with trastuzumab and a taxane as first-line treatment for HER2-positive metastatic breast cancer in a RL setting, and compared the safety results obtained in our population versus the experimental cohort of the CLEOPATRA RCT, which led to the approval of this therapy.

MATERIALS AND METHODS

Patients treated with trastuzumab, pertuzumab and a taxane were enrolled in this retrospective study. We compared the tumor features and the patients' characteristics of the RL cohort to those of the CLEOPATRA cohort. We also compared the median progression-free survival (PFS) in the RL population versus specific patients' subgroups.

RESULTS

RL patients were more frequently HR-positive, less likely to have visceral metastases (P < .001 for both) and had more frequently received (neo)adjuvant hormone therapy or trastuzumab than CLEOPATRA patients (P = .004 and P < .001, respectively). The median number of anti-HER2 cycles was 8 vs 24 and the median number of cycles was 7 vs 8 for docetaxel in the RL versus CLEOPATRA population, respectively. Adverse reactions of all grades were less frequent in RL. Median PFS was 27.8 months in the RL population and the treatment was equally effective in all patients' subgroups.

CONCLUSION

This study provides compelling evidence that pertuzumab, trastuzumab and a taxane are effective and safe also in a clinical scenario.

Evaluation of Left Ventricular Ejection Fractions in Breast Cancer Patients Undergoing Long-Term Trastuzumab Treatment

Background

The aim of this study was to assess the long-term clinical tolerance and cardiac safety during trastuzumab treatment for patients diagnosed as having breast cancer with human epidermal growth factor receptor 2 (HER2) overexpression.

Material/Methods

A total 105 female cases diagnosed as having breast cancer with high expression of Her2, were treated with trastuzumab (T). All of them underwent electrocardiography monitoring in the process of T treatment. Left ventricular ejection fractions (LVEFs) were estimated using echocardiography before the T treatment and every 3 months. General clinical data and above parameters were collected and reviewed as analysis.

Results

The mean value of LVEFs with baseline was higher than those at other time points. All LVEFs were more than 50% during the course of trastuzumab treatment. The decline scope ≥15% of LVEFs ranged from 2 months to 16 months, and the ratios were counted for 3.1% at 2 months, 4.3% at 6 months, 3.8% at 10 months, and 5.4% at 16 months. Furthermore, a larger decrease of LVEF during the course occurred mainly in the patients with cumulative dose of A >300 mg/m², without CPD and 16-month duration of T treatment. There was a strong correlation between cumulative dose of A, cyto/cardio-protection drugs (CPD), duration of T, and the change of LVEF (P=0.82, P=0.744, and P=0.717, respectively), which indicated that 3 factors may be associated with the change in LVEF (P<0.05).

Conclusions

The LVEF in patients with trastuzumab treatment was significantly decreased, which may be seen as a favorable benefit-risk ratio for patients undergoing long-term trastuzumab treatment.

Chemotherapy versus endocrine therapy as first-line treatment in patients with luminal-like HER2-negative metastatic breast cancer: A propensity score analysis

BACKGROUND

According to current guidelines, endocrine therapy (ET) is recommended as first-line treatment of luminal-like metastatic breast cancer (MBC), whereas chemotherapy (CT) should be considered in presence of life-threatening disease. In daily practice, CT is often used outside of this clinical circumstance. Factors influencing first-line choice and the relative impact on outcome are unknown.

METHODS

A consecutive series of luminal-like HER2-negative MBC patients treated from 2004 to 2014 was analyzed to test the association of disease- and patient-related factors with the choice of first-line treatment (ET vs. CT). A propensity score method was used to estimate impact of first-line strategy on outcome.

RESULTS

Of 604 consecutive luminal-like MBC patients identified, 158 cases were excluded due to unknown or positive HER2-status. Among 446 HER2-negative cases, 171 (38%) received first-line CT. On multivariate analysis, the only factors significantly associated with lower CT use were old age (OR 0.25, 95%C.I. 0.13-0.49) or presence of bone metastases only (OR 0.26, 95%C.I. 0.13-0.53). In propensity score matched population, no differences were observed between CT and ET as first-line treatment either in terms of overall survival (37.5 months and 33.4 months respectively, log-rank test, P = 0.62) or progression-free survival (13.3 months and 9.9 months respectively, log-rank test, P = 0.92).

CONCLUSIONS

High percentage of patients with luminal-like MBC received CT as first-line therapy in real-life. The choice was mainly driven by age and site of metastases. With the limitations of a non-randomized comparison, no differences on patients' outcome were observed depending on the first-line strategy.