Human epidermal growth factor receptor 2-positive breast cancer and central nervous system metastases

Efficacy and safety of pyrotinib-based regimens in HER2 positive metastatic breast cancer: A retrospective real-world data study

OBJECTIVE

Pyrotinib is a novel irreversible tyrosine kinase inhibitor that has shown efficacy for human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC). This study explored the efficacy and safety of pyrotinib in the treatment of HER2-positive MBC patients in the real world.

METHODS

From September 2018 to February 2022, 137 female patients with HER2-positive MBC treated in this center were enrolled in this study. The follow-up period ended on January 12, 2023. The primary endpoint of this study was progression-free survival (PFS). Overall survival (OS), objective response rate (ORR), disease control rate (DCR), clinical benefit rate (CBR), central nervous system (CNS)-PFS, CNS-ORR, CNS-CBR, CNS-DCR, and adverse event (AE) were the secondary endpoints.

RESULTS

The ORR, DCR and CBR were 41.98 % (55/131), 87.79 % (115/131) and 44.27 % (58/131) in this cohort, respectively. The median PFS for this cohort was 10.37 months [95 % confidence interval (CI): 9.205-11.535] and the median OS was 37.53 months (not reached). Univariate and multivariate analyses showed that trastuzumab sensitivity was an independent predictor of improved PFS [hazard ratio (HR): 0.579 (0.371-0.904, p=0.016)] and improved OS [0.410 (0.213-0.790, p=0.008)]. Patients treated with a pyrotinib-based regimen as second-line and third-or-post-line therapy had poorer PFS [second-line: 3.315 (1.832-6.000, p<0.001); third-or-post-line: 3.304 (1.749-6.243, p<0.001)] and OS [second-line: 4.631 (1.033-20.771, p=0.045); third-or-post-line: 5.738 (1.212-27.174, p=0.028)]. There were 38 brain metastases (BM) patients in this study, the CNS-mPFS [14.37 months (7.815-20.925) vs. 7.83 months (7.047-8.613), p=0.375] and mOS [not reached vs. 36.40 months (18.551-54.249), p=0.034] were better in brain radiotherapy (BRT) group than NBRT group. 18.98 % (26/137) of patients experienced grade 3 or higher diarrhea. No AE-related death was reported.

CONCLUSION

This study confirms the promising antitumor activity and acceptable safety of real-world pyrotinib-based regimens for the treatment of HER2-positive MBC patients, particularly those who are trastuzumab-sensitive and who are receiving pyrotinib-based regimens as advanced first-line therapy. It has also been demonstrated that these regimens combined with BRT, provide better intracranial responses and long-term survival benefits for these patients with BM.

Incidence and outcome of brain and/or leptomeningeal metastases in HER2-low metastatic breast cancer in the French ESME cohort

BACKGROUND

Breast cancer (BC) is the second most common cancer that metastasizes to the brain. Particularly up to half of patients with human epidermal growth factor receptor 2 (HER2)-positive (HER2+) metastatic breast cancer (mBC) may develop brain metastases over the course of the disease. Nevertheless, little is known about the prevalence and the outcome of brain and leptomeningeal metastases (BLMM) in HER2-low BC. We compared the cumulative incidence of BLMM and associated outcomes among patients with HER2-low, HER2-negative (HER2-) and HER2+ mBC.

PATIENTS AND METHODS

This cohort study was conducted from the Epidemiological Strategy and Medical Economics (ESME) mBC database and included patients treated for mBC between 2012 and 2020 across 18 French comprehensive cancer centers and with known HER2 and hormone receptor (HR) status. The cumulative incidence of BLMM after metastatic diagnosis was estimated using a competing risk methodology with death defined as a competing event.

RESULTS

19 585 patients were included with 6118 (31.2%), 9943 (50.8%) and 3524 (18.0%) being HER2-low, HER2- and HER2+ mBC, respectively. After a median follow-up of 48.6 months [95% confidence interval (CI) 47.7-49.3 months], BLMM were reported in 4727 patients: 1192 (25.2%) were diagnosed with BLMM at first metastatic diagnosis and 3535 (74.8%) after metastatic diagnosis. Multivariable analysis adjusted for age, histological grade, metastases-free interval and HR status showed that the risk of BLMM at metastatic diagnosis was similar in patients with HER2- compared to HER2-low mBC [odds ratio (OR) (95% CI) 1.00 (0.86-1.17)] and higher in those with HER2+ compared to HER2-low [OR (95% CI) 2.23 (1.87-2.66)]. Similar results were found after metastatic diagnosis; the risk of BLMM was similar in HER2- compared to HER2-low [subdistribution hazard ratio (sHR) (95% CI) 1.07 (0.98-1.16)] and higher in the HER2+ group [sHR (95% CI) 1.56 (1.41-1.73)].

CONCLUSIONS

The prevalence and evolution of BLMM in HER2-low mBC are similar to those in patients with HER2- tumors. In contrast to patients with HER2+ mBC, the prognosis of BLMM remains dismal in this population.

Concurrent Lapatinib With Brain Radiation Therapy in Patients With HER2+ Breast Cancer With Brain Metastases: NRG Oncology-KROG/RTOG 1119 Phase 2 Randomized Trial

PURPOSE

Lapatinib plus whole brain radiation therapy (WBRT) or stereotactic radiosurgery (SRS) was hypothesized to improve the 12-week intracranial complete response (CR) rate compared with either option of radiation therapy (RT) alone for patients with brain metastases (BM) from human epidermal growth factor receptor 2-positive (HER2+) breast cancer.

METHODS AND MATERIALS

This study included patients with HER2+ breast cancer with ≥1 measurable, unirradiated BM. Patients were randomized to WBRT (37.5 Gy/3 wk)/SRS (size-based dosing) ± concurrent lapatinib (1000 mg daily for 6 weeks). Secondary endpoints included objective response rate (ORR), lesion-specific response, central nervous system progression-free survival, and overall survival.

RESULTS

From July 2012 to September 2019, 143 patients were randomized, with 116 analyzable for the primary endpoint. RT + lapatinib did not improve 12-week CR (0% vs 6% for RT alone, 1-sided P = .97), or ORR at 12 weeks. At 4 weeks, RT + lapatinib showed higher ORR (55% vs 42%). Higher graded prognostic assessment and ≤10 lesions were associated with higher 12-week ORR. Grade 3 and 4 adverse event rates were 8% and 0% for RT and 28% and 6% for RT + lapatinib.

CONCLUSIONS

The addition of 6 weeks of concomitant lapatinib to WBRT/SRS did not improve the primary endpoint of 12-week CR rate or 12-week ORR. Adding lapatinib to WBRT/SRS showed improvement of 4-week ORR, suggesting a short-term benefit from concomitant therapy.

Brain Radiotherapy With Pyrotinib and Capecitabine in Patients With ERBB2-Positive Advanced Breast Cancer and Brain Metastases: A Nonrandomized Phase 2 Trial

Importance

The potential benefit of combining intracranial effective systemic therapy with radiotherapy for patients with breast cancer with brain metastases remains unclear.

Objective

To assess the activity and safety of combining radiotherapy with pyrotinib and capecitabine in patients with ERBB2-positive breast cancer and brain metastases.

Design, Setting, and Participants

This was a single-arm, single-center, phase 2 nonrandomized clinical trial with a safety run-in phase. Between January 2020 and August 2022, patients with ERBB2-positive breast cancer and brain metastases were enrolled. The data cutoff date was February 1, 2023.

Interventions

Patients received either fractionated stereotactic radiotherapy or whole-brain radiotherapy. Treatment with pyrotinib (400 mg, once daily) and capecitabine (1000 mg/m2, twice daily, on days 1-14 of each 21-day cycle) was initiated from the first day of radiotherapy to the seventh day after the completion of radiotherapy and continued until disease progression or unacceptable toxic effects.

Main Outcomes and Measures

The primary end point was 1-year central nervous system (CNS) progression-free survival (PFS) rate. Secondary end points included CNS objective response rate (ORR), PFS, overall survival (OS), safety, and changes in neurocognitive function.

Results

A total of 40 female patients (median age, 50.5 years [IQR, 46-59 years]) were enrolled and received treatment, including 3 patients in safety run-in phase. With a median follow-up of 17.3 months (IQR, 10.3-26.9), the 1-year CNS PFS rate was 74.9% (95% CI, 61.9%-90.7%), and the median CNS PFS was 18.0 months (95% CI, 15.5 to not reached). The 1-year PFS rate was 66.9% (95% CI, 53.1%-84.2%), and the median PFS was 17.6 months (95% CI, 12.8-34.1). The CNS objective response rate was 85% (34 of 40). Median overall survival was not reached. The most common grade 3 or 4 treatment-related adverse event was diarrhea (7.5%). Asymptomatic radiation necrosis was identified in 4 of 67 lesions (6.0%) treated with fractionated stereotactic radiotherapy. Most patients maintained neurocognitive function, as evaluated by the Mini-Mental State Examination at different points.

Conclusions and Relevance

The results of this trial suggest that radiotherapy combined with pyrotinib and capecitabine is associated with long intracranial survival benefit in patients with ERBB2-positive advanced breast cancer and brain metastases with an acceptable safety profile. This combination deserves further validation.

Trial Registration

ClinicalTrials.gov Identifier: NCT04582968.

Central nervous system metastases in breast cancer patients with germline BRCA pathogenic variants compared to non-carriers: a matched-pair analysis

BACKGROUND

Breast cancer is a common cause for central nervous system (CNS) metastasis, resulting in a significant reduction in overall survival. Germline pathogenic variants (PVs) in BRCA1/2 are the most common genetic risk factor for breast cancer, associated with poor prognostic factors. This study sought to explore the patterns and outcome of CNS metastases in breast cancer patients with germline PVs in BRCA1/2 genes.

METHODS

A retrospective cohort of 75 breast cancer patients with known BRCA1/2 mutation status, who were diagnosed with CNS metastases in 2006-2021. Histopathology, characteristics of CNS disease, treatments, and survival were compared between BRCA1/2 carriers (n = 25) and non-carriers (n = 50), using propensity score matching (1:2 ratio) to control for the possible influence of tumor receptor status (ER, PR, HER2) and patient age. Pearson chi-square or Fisher exact test and Kaplan-Meier survival curves with log-rank test were used for statistical analyses.

RESULTS

Patients with PVs in BRCA1/2 had more high-grade tumors (88% vs. 68%, P = 0.060), were younger at CNS disease diagnosis (median 46.69 vs. 55.02 years, P = 0.003) and had better ECOG performance status (ECOG PS 0 in 20% vs. 2%, P = 0.033), but without significant differences in systemic or CNS-directed treatment approaches. BRCA1/2 mutation was associated with a higher rate of temporal lobe involvement (52% vs. 26%, P = 0.026) and leptomeningeal spread (40% vs. 20%, P = 0.020). Survival after diagnosis of CNS disease was shorter (median 8.03 vs. 28.36 months, P < 0.0001), with no significant differences in time to development of CNS metastases or overall-survival.

CONCLUSION

Patients with CNS metastatic breast cancer and PVs in BRCA1/2 showed a higher rate of leptomeningeal and temporal lobe involvement, and a shorter survival with CNS disease. To the best of our knowledge, this is the first study suggesting an exclusive impact of germline BRCA1/2 mutations in CNS metastatic breast cancer.

New approaches for human epidermal growth factor receptor 2-low and human epidermal growth factor receptor 2-overexpressing metastatic breast cancer

PURPOSE OF REVIEW

In recent years, there has been a flurry of activity in the human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer space. New, powerful drugs like trastuzumab deruxtecan have challenged our fundamental definition of what HER2 expression means as a predictive biomarker.

RECENT FINDINGS

Recent approvals of multiple agents in the second line-metastatic setting have given patients access to a variety of new agents, but also raise questions with regard to optimal sequencing.

SUMMARY

This review will explore current issues with HER2 testing, recently approved drugs in the HER2+ and HER2 low spaces, as well as novel agents/combinations on the horizon.

Comparing pyrotinib with trastuzumab and pertuzumab with trastuzumab for HER2-positive metastatic breast cancer: a retrospective, multicenter analysis

Objective

Pyrotinib and pertuzumab are effective treatment options for HER2-positive metastatic breast cancer (HER2+ MBC). Our study was to directly compare the efficacy and safety of pyrotinib plus trastuzumab (PyroH) and pertuzumab plus trastuzumab (HP) in patients with HER2+ MBC.

Methods

We conducted a retrospective examination of HER2+ MBC patients who received PyroH plus chemotherapy or HP plus chemotherapy between 2017 and 2022 at five institutions in China. Our primary endpoint was progression-free survival (PFS).

Results

This study involved 333 patients, among which 161 received PyroH and 172 received HP. The utilization of PyroH as a first-line therapy for MBC was more prevalent among older patients, those with a shorter duration of disease-free interval, or those who had previously been treated with trastuzumab. Although in the first-line advanced treatment HP cohort showed numerically longer PFS (median PFS: 14.46 vs. 22.90 months, p=0.057), in the second-line or later treatments, there was no significant difference in PFS between the PyroH and HP groups (median PFS: 8.67 vs. 7.92 months, p=0.286). Despite HP showing a longer PFS in the overall cohort (median PFS: 9.30 vs. 13.01 months, p=0.005), it did not serve as an independent predictor of PFS in the multivariate analysis (HR 1.134, 95% CI 0.710-1.811, p=0.598). Without taxane, PyroH demonstrated a longer PFS than HP (median PFS: 10.12 vs. 8.15 months, p=0.017). PyroH group displayed a numerically longer median PFS in patients with brain metastases compared to the HP group, though not statistically significant (median PFS: 9.03 vs. 8.15 months, p=0.976). PyroH had higher incidence of grade 3/4 diarrhea (34.3% vs. 3.0%) but similar overall adverse events.

Conclusion

In conclusion, PyroH is comparable in second-line or later treatment and during brain metastasis, even having superior efficacy without taxane in real-world setting. Toxicities were tolerable in both groups. (ClinicalTrials.gov: NCT05572645).

Multidisciplinary management of HER2-positive breast cancer with brain metastases: An evidence-based pragmatic approach moving from pathophysiology to clinical data

INTRODUCTION

About 30-50 % of stage IV HER2+ breast cancers (BC) will present brain metastases (BMs). Their management is based on both local treatment and systemic therapy. Despite therapeutic advances, BMs still impact on survival and quality of life and the development of more effective systemic therapies represents an unmet clinical need.

MATERIALS AND METHODS

A thorough analysis of the published literature including ongoing clinical trials has been performed, investigating concepts spanning from the pathophysiology of tumor microenvironment to clinical considerations with the aim to summarize the current and future locoregional and systemic strategies.

RESULTS

Different trials have investigated monotherapies and combination treatments, highlighting how the blood-brain barrier (BBB) represents a major problem hindering diffusion and consequently efficacy of such options. Trastuzumab has long been the mainstay of systemic therapy and over the last two decades other HER2-targeted agents including lapatinib, pertuzumab, and trastuzumab emtansine, as well as more recently neratinib, tucatinib, and trastuzumab deruxtecan, have been introduced in clinical practice after showing promising results in randomized controlled trials.

CONCLUSIONS

We ultimately propose an evidence-based treatment algorithm for clinicians treating HER2 + BCs patients with BMs.

Nanoparticle drug delivery to target breast cancer brain metastasis: Current and future trends

Breast cancer brain metastasis (BCBM) is rapidly becoming an impediment to continuing survival gains seen in breast cancer patients. Drug delivery across the blood-brain barrier is the main issue hindering systemic therapy against BCBM. This review details recent advances in nanoparticle (NP) drug delivery systems to target BCBM. Their primary benefits are: enhanced circulating and intra-BCBM drug biodistribution, BCBM targeting through NP functionalization, opportunities for gene manipulation and their theragnostic applications. Multiple NPs have been synthesized to deliver therapeutic HER2 blockade, which is particularly important given HER2-positive breast cancer's tendency to form BCBM. Finally, we review the clinical context in which NP-based therapeutics have been investigated in BCBM patients. While a breakthrough in improving patient outcomes remain awaited, these clinical trials represent positive steps in the changing attitude towards BCBM as a treatable illness. Although multiple challenges remain in the clinical translation of BCBM-directed NP therapies, ongoing research in the field offers promising avenues for novel targeting of this devastating disease.

Improved survival in patients with isolated liver metastasis at initial diagnosis with surgery at primary and metastatic sites: A population-based study in patients with breast cancer

BACKGROUND

The aim of this study was to investigate epidemiological characteristics, risk factors, optimal treatment options, and survival outcomes of breast cancer patients with isolated liver metastasis (BCILM).

METHODS

Patients with breast cancer (BC) were selected from Incidence-Surveillance, Epidemiology, and End Results (SEER) Research Plus Data, 17 registries between 2010 and 2019. The Kaplan-Meier method and log-rank test were used to compare survival rates between patients who received or did not receive surgery for the primary and liver metastatic sites. Univariate and multivariate analyses were conducted using Cox regression analysis.

RESULTS

This study included 17 743 stage IV BC patients, with 3604 (20.3%) patients experiencing liver metastasis at initial diagnosis. Of 3604 liver metastasis patients, 951 were diagnosed with BCILM. The median survival time of patients with BCILM who underwent surgery at the primary site (52.0 months) or distant sites (85.0 months) was significantly longer than that of patients who did not undergo surgery at the primary site (23.0 months) or distant sites (32.0 months). Univariate analysis indicated that age, race, histological grade, molecular subtype, T stage, N stage, surgery of the primary site, surgery to other regional/distant sites, radiotherapy, and chemotherapy were prognostic factors affecting the overall survival (OS) and cancer-specific survival (CSS) of patients with BCILM (p < 0.05). Multivariate analysis suggested that age, race, molecular subtype, T stage, surgery of the primary site, radiotherapy, and chemotherapy were independent prognostic factors. In the BCILM cohort, HR+ /HER2+ patients exhibited the best OS and CSS, followed by HR- /HER2+ , HR+ /HER2- , and HR- /HER2- patients (p < 0.0001; p < 0.0001).

CONCLUSION

Surgery at the primary and metastatic sites was associated with better survival in patients with BCILM. HER2+ patients with BCILM had a significantly better prognosis than HER2- patients.

Real-world data of pyrotinib-based therapy for patients with brain metastases of HER2-positive advanced breast cancer: a single-center retrospective analysis and molecular portraits

Introduction

Pyrotinib is a novel irreversible pan-HER tyrosine kinase inhibitor (TKI). However, real-world data of pyrotinib-containing therapy in human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) and developing brain metastases (BMs) are limited, and the genomic profile of this subpopulation is almost undefined.

Methods and materials

Patients with BM of HER2-positive MBC (n = 35) treated with pyrotinib-containing therapy were enrolled in this analysis. Progression-free survival (PFS), overall survival (OS), objective response rate (ORR), disease control rate (DCR), and toxicity profiles were evaluated. Hazard ratios (HRs) and 95% confidence intervals (CIs) for disease progression were estimated using the Cox proportional hazards models. Targeted next-generation sequencing of 618 cancer-relevant genes was performed on plasma and primary breast tumors from patients with BM and without BM.

Results

The median PFS time was 8.00 (95% CI, 5.98-10.017) months, and the median OS time was 23 (95% CI, 10.412-35.588) months. The ORR was 45.7%, and the DCR was 74.3%. In the Cox multivariate analysis, prior exposure to brain radiotherapy (HR = 3.268), received pyrotinib as third- or higher-line treatment (HR = 4.949), subtentorial brain metastasis (HR = 6.222), and both supratentorial and subtentorial brain metastases (HR = 5.863) were independently associated with increased risk of progression. The frequent grade 3-4 adverse event was increased direct bilirubin (14.3%), and two patients suffered from grade 3-4 diarrhea. In the exploratory genomic analysis, altered frequencies of FGFR3, CD276, CDC73, and EPHX1 were higher in the BM group. The consistency of mutated profiles of plasma and primary lesion in the BM group was significantly lower (30.4% vs. 65.5%; p = 0.0038).

Conclusions

Pyrotinib-containing therapy shows favorable effectiveness and tolerable safety in patients with BM of HER2-positive MBC, particularly in a population that is brain radiotherapy-naïve, received pyrotinib as first- or second-line treatment, and developed supratentorial brain metastasis. In the exploratory genomic analysis, patients with BM showed distinct genomic features from patients without BM.

TME-targeted approaches of brain metastases and its clinical therapeutic evidence

The tumor microenvironment (TME), which includes both cellular and non-cellular elements, is now recognized as one of the major regulators of the development of primary tumors, the metastasis of which occurs to specific organs, and the response to therapy. Development of immunotherapy and targeted therapies have increased knowledge of cancer-related inflammation Since the blood-brain barrier (BBB) and blood-cerebrospinal fluid barrier (BCB) limit immune cells from entering from the periphery, it has long been considered an immunological refuge. Thus, tumor cells that make their way "to the brain were believed to be protected from the body's normal mechanisms of monitoring and eliminating them. In this process, the microenvironment and tumor cells at different stages interact and depend on each other to form the basis of the evolution of tumor brain metastases. This paper focuses on the pathogenesis, microenvironmental changes, and new treatment methods of different types of brain metastases. Through the systematic review and summary from macro to micro, the occurrence and development rules and key driving factors of the disease are revealed, and the clinical precision medicine of brain metastases is comprehensively promoted. Recent research has shed light on the potential of TME-targeted and potential treatments for treating Brain metastases, and we'll use that knowledge to discuss the advantages and disadvantages of these approaches.

c-Met Mediated Cytokine Network Promotes Brain Metastasis of Breast Cancer by Remodeling Neutrophil Activities

The brain is one of the most common metastatic sites among breast cancer patients, especially in those who have Her2-positive or triple-negative tumors. The brain microenvironment has been considered immune privileged, and the exact mechanisms of how immune cells in the brain microenvironment contribute to brain metastasis remain elusive. In this study, we found that neutrophils are recruited and influenced by c-Met high brain metastatic cells in the metastatic sites, and depletion of neutrophils significantly suppressed brain metastasis in animal models. Overexpression of c-Met in tumor cells enhances the secretion of a group of cytokines, including CXCL1/2, G-CSF, and GM-CSF, which play critical roles in neutrophil attraction, granulopoiesis, and homeostasis. Meanwhile, our transcriptomic analysis demonstrated that conditioned media from c-Met high cells significantly induced the secretion of lipocalin 2 (LCN2) from neutrophils, which in turn promotes the self-renewal of cancer stem cells. Our study unveiled the molecular and pathogenic mechanisms of how crosstalk between innate immune cells and tumor cells facilitates tumor progression in the brain, which provides novel therapeutic targets for treating brain metastasis.

The Blood-Brain Barrier: Implications for Experimental Cancer Therapeutics

The blood-brain barrier is critically important for the treatment of both primary and metastatic cancers of the central nervous system (CNS). Clinical outcomes for patients with primary CNS tumors are poor and have not significantly improved in decades. As treatments for patients with extracranial solid tumors improve, the incidence of CNS metastases is on the rise due to suboptimal CNS exposure of otherwise systemically active agents. Despite state-of-the art surgical care and increasingly precise radiation therapy, clinical progress is limited by the ability to deliver an effective dose of a therapeutic agent to all cancerous cells. Given the tremendous heterogeneity of CNS cancers, both across cancer subtypes and within a single tumor, and the range of diverse therapies under investigation, a nuanced examination of CNS drug exposure is needed. With a shared goal, common vocabulary, and interdisciplinary collaboration, the field is poised for renewed progress in the treatment of CNS cancers.

Nanoparticle Targeting with Antibodies in the Central Nervous System

Treatments for disease in the central nervous system (CNS) are limited because of difficulties in agent penetration through the blood-brain barrier, achieving optimal dosing, and mitigating off-target effects. The prospect of precision medicine in CNS treatment suggests an opportunity for therapeutic nanotechnology, which offers tunability and adaptability to address specific diseases as well as targetability when combined with antibodies (Abs). Here, we review the strategies to attach Abs to nanoparticles (NPs), including conventional approaches of chemisorption and physisorption as well as attempts to combine irreversible Ab immobilization with controlled orientation. We also summarize trends that have been observed through studies of systemically delivered Ab-NP conjugates in animals. Finally, we discuss the future outlook for Ab-NPs to deliver therapeutics into the CNS.

Real-world efficacy and safety of pyrotinib in patients with HER2-positive metastatic breast cancer: A prospective real-world study

Background: Pyrotinib, a novel irreversible EGFR/HER2 dual tyrosine kinase inhibitor, shows encouraging anticancer activity and acceptable tolerability in multiple phase II and phase III randomized clinical trials, but the real-world data of pyrotinib, especially the outcomes in HER2-positive metastatic breast cancer, have been rarely reported. Here, we evaluated the treatment outcomes of pyrotinib in real-world practice in patients with HER2-positive metastatic breast cancer (MBC). Methods: This was a prospective, real-world, observational cohort study. Through the Breast Cancer Information Management System, HER-2 positive MBC patients treated with pyrotinib between 2017/06 and 2020/09 were included. Provider-reported objective response rate, progression-free survival (PFS), and overall survival (OS) were considered in the assessment of treatment outcomes. Tumor responses to pyrotinib treatment were calculated using RECIST 1.1. Adverse events were evaluated using clinical records. Results: The trial involved 113 individuals who were receiving pyrotinib treatment, with an average age of 51 years. Complete response, partial response and stable disease were observed in 9 (8.0%), 66 (58.4%), and 17 (15.0%) patients, respectively, while progressive disease was recorded in 20 (17.7%) patients. After a median follow-up of 17.2 months, the median PFS was 14.1. The most common adverse events of any grade were diarrhea (87.6%), vomiting (31.9%), and palmar-plantar erythrodysesthesia (26.6%). Among the patients with brain metastases, the median PFS and OS were 15.2 and 19.8 months, respectively. In addition, pyrotinib has similar efficacy in various subtypes of HER2-positive MBC patients, as shown by the lack of a significant difference of PFS and OS among pyrotinib-treated patients with or without brain metastases, or patients using pyrotinib as first-line, second-line, third-line or beyond therapies. Conclusion: Our real-world results demonstrated equivalent clinical efficacy in HER-2 positive MBC patients compared to phase II and phase III clinical trials with pyrotinib, and promising outcomes in patients with brain metastases.

Incidence, characteristics, and management of central nervous system metastases in patients with inflammatory breast cancer

BACKGROUND

Patients with inflammatory breast cancer (IBC) have a high risk of central nervous system metastasis (mCNS). The purpose of this study was to quantify the incidence of and identify risk factors for mCNS in patients with IBC.

METHODS

The authors retrospectively reviewed patients diagnosed with IBC between 1997 and 2019. mCNS-free survival time was defined as the date from the diagnosis of IBC to the date of diagnosis of mCNS or the date of death, whichever occurred first. A competing risks hazard model was used to evaluate risk factors for mCNS.

RESULTS

A total of 531 patients were identified; 372 patients with stage III and 159 patients with de novo stage IV disease. During the study, there were a total of 124 patients who had mCNS. The 1-, 2-, and 5-year incidence of mCNS was 5%, 9%, and 18% in stage III patients (median follow-up: 5.6 years) and 17%, 30%, and 42% in stage IV patients (1.8 years). Multivariate analysis identified triple-negative tumor subtype as a significant risk factor for mCNS for stage III patients. For patients diagnosed with metastatic disease, visceral metastasis as first metastatic site, triple-negative subtype, and younger age at diagnosis of metastases were risk factors for mCNS.

CONCLUSIONS

Patients with IBC, particularly those with triple-negative IBC, visceral metastasis, and those at a younger age at diagnosis of metastatic disease, are at significant risk of developing mCNS. Further investigation into prevention of mCNS and whether early detection of mCNS is associated with improved IBC patient outcomes is warranted.

Efficacy and Safety of Pyrotinib in Human Epidermal Growth Factor Receptor 2-Positive Advanced Breast Cancer: A Multicenter, Retrospective, Real-World Study

Purpose

Pyrotinib, a novel human epidermal growth factor receptor 2 (HER2)-targeted tyrosine kinase inhibitor (TKI), has led to remarkable survival outcomes in HER2-positive advanced breast cancer (ABC) in clinical trials and was approved for second-line standards of treatment for HER2+ ABC in China. However, the clinical trials could not fully reflect reality of clinical practice, and predictive factors were still lacking. This study aimed to assess the actual efficacy and safety of pyrotinib in HER2+ ABC in real-world setting.

Patients and Methods

In this multicenter, retrospective, observational real-world study, we analyzed 171 patients with HER2+ ABC, who received pyrotinib-based treatment from November 2017 to November 2020. The primary end point was progression-free survival (PFS). Secondary end points included overall survival (OS), objective response rate (ORR), clinical benefit rate (CBR) and safety.

Results

Up to November 30, 2021, the median PFS (mPFS) was 12.0 months for all patients. One hundred and sixty-two patients (94.7%) with measurable lesions had been included in efficacy assessment. The ORR and CBR were 45.1% and 81.5%, respectively. A significantly longer PFS was reported in patients who received pyrotinib as first-line treatment, had the ECOG-PS of 0–1, as well as those who were lapatinib-naive. In addition, multivariable analysis indicated that ECOG-PS of 2–4, positive hormone receptor (HR) status, and presence of visceral metastasis were independent negative predictors of PFS. As far as we know, this study first reported the survival outcome of pyrotinib cross-line treatment, with a mPFS of 5.0 months. All grades of adverse events (AEs) occurred in 171 patients (100%), and the most common AE was diarrhea (86.5%).

Conclusion

This study further demonstrated the outstanding efficacy and safety of pyrotinib and reported the potential predictors of survival in HER2+ ABC.

Mechanistic Modeling of Central Nervous System Pharmacokinetics and Target Engagement of HER2 Tyrosine Kinase Inhibitors to Inform Treatment of Breast Cancer Brain Metastases

PURPOSE

This study evaluated the central nervous system (CNS) pharmacokinetics and target engagement of lapatinib, neratinib, and tucatinib in patients with cancer, using a physiologically based pharmacokinetic (PBPK) modeling approach.

EXPERIMENTAL DESIGN

Drug-specific parameters for in vitro metabolism, binding to plasma proteins and brain tissues, transcellular passive permeability, and interactions with efflux transporters were determined. Whole-body PBPK models integrated with a 4-compartment permeability-limited brain model was developed and verified for predicting plasma and CNS pharmacokinetics. Target engagement ratio (TER), defined as the ratio of the average steady-state unbound drug brain concentration (Css,ave,br) to in vitro IC50 for HER2 inhibition, was used as a predictor of intracranial efficacy.

RESULTS

PBPK models predicted that following 1 cycle of standard dosing, tucatinib and lapatinib achieved similar Css,ave,br (14.5 vs. 16.8 nmol/L), while neratinib Css,ave,br (0.68 nmol/L) was 20-fold lower. Tucatinib and neratinib were equally potent for HER2 inhibition (IC50, 6.9 vs. 5.6 nmol/L), while lapatinib was less potent (IC50, 109 nmol/L). The model-predicted population mean TER in the human normal brain was 2.1 for tucatinib, but < 0.20 for lapatinib and neratinib.

CONCLUSIONS

The PBPK modeling suggests that tucatinib induces sufficient HER2 inhibition (TER > 2.0) in not only brain metastases with a disrupted blood-brain barrier (BBB), but also micrometastases where the BBB largely remains intact. These findings, in line with available clinical pharmacokinetics and efficacy data, support the therapeutic value of tucatinib for treatment of brain metastases and warrant further clinical investigation for the prevention of brain metastases in patients with HER2-positive breast cancer.

Local and systemic therapy in breast cancer patients with central nervous system metastases

PURPOSE

As survival of patients with central nervous system (CNS) metastases from breast cancer is poor and incidence rates are increasing, there is a growing need for better treatment strategies. In the current study, the efficacy of local and systemic therapies was analyzed in breast cancer patients with CNS metastases.

METHODS

Medical records from breast cancer patients with brain and/or leptomeningeal metastases (LM) treated at a tertiary referral center and a teaching hospital between 2010 and 2020 were retrospectively studied. Main outcomes of interest were overall survival (OS) and CNS progression free survival. Analyses were performed among patients with brain metastases (BM) and patients with LM, for the different systemic and local therapies for CNS metastases, and for subgroups based on breast cancer subtypes.

RESULTS

We identified 155 patients, 97 with BM and 58 with LM. Median OS was 15.9 months for patients with BM and 1.5 months for patients with LM. Median OS was significantly longer for HER2-positive patients with BM (22.8 months) vs triple negative (8.4 months) and hormone receptor positive/HER2-negative (5.9 months) (P < 0.001). Patients with BM receiving both local and systemic therapy also had a longer median OS (21.8 months), compared to the other three subgroups (local therapy only: 9.9 months, systemic therapy only: 4.3 months, no therapy: 0.5 months, P < 0.001). No significant difference in OS was observed between different systemic treatment regimens.

CONCLUSION

Breast cancer patients with BM show longest median OS when the subtype is HER2-positive and when they are treated with both local and systemic therapy.

Targeted Nanoparticle for Co-delivery of HER2 siRNA and a Taxane to Mirror the Standard Treatment of HER2+ Breast Cancer: Efficacy in Breast Tumor and Brain Metastasis

The first-line treatment of advanced and metastatic human epidermal growth factor receptor type 2 (HER2+) breast cancer requires two HER2-targeting antibodies (trastuzumab and pertuzumab) and a taxane (docetaxel or paclitaxel). The three-drug regimen costs over $320,000 per treatment course, requires a 4 h infusion time, and has many adverse side effects, while achieving only 18 months of progression-free survival. To replace this regimen, reduce infusion time, and enhance efficacy, a single therapeutic is developed based on trastuzumab-conjugated nanoparticles for co-delivering docetaxel and siRNA against HER2 (siHER2). The optimal nanoconstruct has a hydrodynamic size of 100 nm and specifically treats HER2+ breast cancer cells over organ-derived normal cells. In a drug-resistant orthotopic HER2+ HCC1954 tumor mouse model, the nanoconstruct inhibits tumor growth more effectively than the docetaxel and trastuzumab combination. When coupled with microbubble-assisted focused ultrasound that transiently disrupts the blood brain barrier, the nanoconstruct inhibits the growth of trastuzumab-resistant HER2+ BT474 tumors residing in the brains of mice. The nanoconstruct has a favorable safety profile in cells and in mice. Combination therapies have become the cornerstone of cancer treatment and this versatile nanoparticle platform can co-deliver multiple therapeutic types to ensure that they reach the target cells at the same time to realize their synergy.

Tucatinib versus placebo added to trastuzumab and capecitabine for patients with pretreated HER2+ metastatic breast cancer with and without brain metastases (HER2CLIMB): final overall survival analysis

BACKGROUND

In the primary analysis of the HER2CLIMB trial, tucatinib added to trastuzumab and capecitabine significantly improved overall survival (OS) and progression-free survival (PFS) in patients with human epidermal growth factor receptor 2 positive (HER2+) metastatic breast cancer. We report efficacy and safety outcomes, including the final OS and safety outcomes from follow-up in HER2CLIMB.

PATIENTS AND METHODS

HER2CLIMB is a randomized, double-blind, placebo-controlled trial in patients with locally advanced or metastatic HER2+ breast cancer, including patients with brain metastases. Patients were randomized 2 : 1 to receive tucatinib or placebo, in combination with trastuzumab and capecitabine. After the primary analysis (median follow-up of 14 months), the protocol was amended to allow for unblinding sites to treatment assignment and cross-over from the placebo combination to the tucatinib combination. Protocol prespecified descriptive analyses of OS, PFS (by investigator assessment), and safety were carried out at ∼2 years from the last patient randomized.

RESULTS

Six hundred and twelve patients enrolled in the HER2CLIMB trial. At a median OS follow-up of 29.6 months, median duration of OS was 24.7 months for the tucatinib combination group versus 19.2 months for the placebo combination group [hazard ratio (HR) for death: 0.73, 95% confidence interval (CI): 0.59-0.90, P = 0.004] and OS at 2 years was 51% and 40%, respectively. HRs for OS across prespecified subgroups were consistent with the HR for the overall study population. Median duration of PFS was 7.6 months for the tucatinib combination group versus 4.9 months for the placebo combination group (HR for progression or death: 0.57, 95% CI: 0.47-0.70, P < 0.00001) and PFS at 1 year was 29% and 14%, respectively. The tucatinib combination was well tolerated with a low rate of discontinuation due to adverse events.

CONCLUSIONS

With additional follow-up, the tucatinib combination provided a clinically meaningful survival benefit for patients with HER2+ metastatic breast cancer.

Treatments on the Horizon: Breast Cancer Patients with Central Nervous System Metastases

PURPOSE OF REVIEW

The goal of this paper is to provide a review on the current emerging management strategies as described in the literature pertaining to breast cancer and central nervous system metastases. As systemic oncology treatments evolve, so are new approaches to the management of central nervous system metastases from breast cancer.

RECENT FINDINGS

In this review, we describe how novel treatment strategies have evolved from standard chemotherapy to more targeted approaches, innovative drug delivery methodologies, immunotherapeutics, and radiotherapeutic approaches. We describe innovative treatment strategies on the horizon for breast cancer and central nervous metastases. Future therapeutics may be better able to penetrate through the blood-brain-barrier bypassing limitations from standard therapies. These pioneering strategies will hopefully improve patients' quality of life as well as survival.

Updates on targeting human epidermal growth factor receptor 2-positive breast cancer: what's to know in 2021

PURPOSE OF REVIEW

To highlight recent practice changing clinical trials, focusing on those leading to new drug approvals, in human epidermal growth factor receptor 2-positive (HER2+) breast cancer.

RECENT FINDINGS

The improved disease-free survival of adjuvant trastuzumab emtansine (T-DM1) over trastuzumab in patients with residual disease has made neoadjuvant sequencing of therapy standard for most patients with early stage disease. In patients with metastatic HER2+ breast cancer, trastuzumab deruxtecan has recently shown dramatically improved efficacy over T-DM1. Tucatinib is an oral tyrosine kinase inhibitor with best in class blood-brain barrier penetration. Margetuximab, a novel HER2-targeted chimeric monoclonal antibody with an engineered Fc receptor designed to activate local immune response, was recently approved in heavily pretreated patients based on modest but significant improvement in progression-free survival.

SUMMARY

Patients with HER2+ breast cancer have a variety of therapeutic options in the early stage and metastatic setting. Optimal sequencing of therapy will depend on patient-specific factors such as site of tumor progression and underlying comorbidities. De-escalation of the first-line metastatic regimen may be considered in select patients with hormone positive/HER2+ breast cancer, by using endocrine therapy instead of chemotherapy in combination with HER2-targeted therapy, which may improve side effects without sacrificing efficacy.

Combination of tucatinib and neural stem cells secreting anti-HER2 antibody prolongs survival of mice with metastatic brain cancer

Brain metastases are among the most severe complications of systemic breast cancer, and overexpression of the human epidermal growth factor receptor 2 (HER2) in breast cancer cells increases the incidence of brain metastases in patients. In this study, we engineered the human-derived, tumor cell tropic neural stem cells LM-NSC008 (LM008) to continuously secrete antibodies against HER2. These anti-HER2 antibodies impaired tumor cell proliferation by inhibiting the PI3K-Akt signaling pathway in HER2+ breast cancer cells in vitro. Importantly, our results demonstrate that the therapeutic combinatorial regimen consisting of LM-NSC008 anti-HER2 antibody-secreting cells and the HER2 kinase inhibitor tucatinib provide therapeutic benefit and prolong survival in preclinical models of HER2+ breast cancer brain metastases.

Brain metastases are a leading cause of death in patients with breast cancer. The lack of clinical trials and the presence of the blood–brain barrier limit therapeutic options. Furthermore, overexpression of the human epidermal growth factor receptor 2 (HER2) increases the incidence of breast cancer brain metastases (BCBM). HER2-targeting agents, such as the monoclonal antibodies trastuzumab and pertuzumab, improved outcomes in patients with breast cancer and extracranial metastases. However, continued BCBM progression in breast cancer patients highlighted the need for novel and effective targeted therapies against intracranial metastases. In this study, we engineered the highly migratory and brain tumor tropic human neural stem cells (NSCs) LM008 to continuously secrete high amounts of functional, stable, full-length antibodies against HER2 (anti-HER2Ab) without compromising the stemness of LM008 cells. The secreted anti-HER2Ab impaired tumor cell proliferation in vitro in HER2+ BCBM cells by inhibiting the PI3K-Akt signaling pathway and resulted in a significant benefit when injected in intracranial xenograft models. In addition, dual HER2 blockade using anti-HER2Ab LM008 NSCs and the tyrosine kinase inhibitor tucatinib significantly improved the survival of mice in a clinically relevant model of multiple HER2+ BCBM. These findings provide compelling evidence for the use of HER2Ab-secreting LM008 NSCs in combination with tucatinib as a promising therapeutic regimen for patients with HER2+ BCBM.

Low-level whole-brain radiation enhances theranostic potential of single-domain antibody fragments for human epidermal growth factor receptor type 2 (HER2)-positive brain metastases

Background

Single-domain antibody fragments (aka V_HH, ~ 13 kDa) are promising delivery systems for brain tumor theranostics; however, achieving efficient delivery of V_HH to intracranial lesions remains challenging due to the tumor–brain barrier. Here, we evaluate low-dose whole-brain irradiation as a strategy to increase the delivery of an anti- human epidermal growth factor receptor type 2 (HER2) V_HH to breast cancer-derived intracranial tumors in mice.

Methods

Mice with intracranial HER2-positive BT474BrM3 tumors received 10-Gy fractionated cranial irradiation and were evaluated by noninvasive imaging. Anti-HER2 V_HH 5F7 was labeled with ¹⁸F, administered intravenously to irradiated mice and controls, and PET/CT imaging was conducted periodically after irradiation. Tumor uptake of ¹⁸F-labeled 5F7 in irradiated and control mice was compared by PET/CT image analysis and correlated with tumor volumes. In addition, longitudinal dynamic contrast-enhanced MRI (DCE-MRI) was conducted to visualize and quantify the potential effects of radiation on tumor perfusion and permeability.

Results

Increased ¹⁸F-labeled 5F7 intracranial tumor uptake was observed with PET in mice receiving cranial irradiation, with maximum tumor accumulation seen approximately 12 days post initial radiation treatment. No radiation-induced changes in HER2 expression were detected by Western blot, flow cytometry, or on tissue sections. DCE-MRI imaging demonstrated transiently increased tumor perfusion and permeability after irradiation, consistent with the higher tumor uptake of ¹⁸F-labeled anti-HER2 5F7 in irradiated mice.

Conclusion

Low-level brain irradiation induces dynamic changes in tumor vasculature that increase the intracranial tumor delivery of an anti-HER2 V_HH, which could facilitate the use of radiolabeled V_HH to detect, monitor, and treat HER2-expressing brain metastases.

Machine learning of genomic features in organotropic metastases stratifies progression risk of primary tumors

Metastatic cancer is associated with poor patient prognosis but its spatiotemporal behavior remains unpredictable at early stage. Here we develop MetaNet, a computational framework that integrates clinical and sequencing data from 32,176 primary and metastatic cancer cases, to assess metastatic risks of primary tumors. MetaNet achieves high accuracy in distinguishing the metastasis from the primary in breast and prostate cancers. From the prediction, we identify Metastasis-Featuring Primary (MFP) tumors, a subset of primary tumors with genomic features enriched in metastasis and demonstrate their higher metastatic risk and shorter disease-free survival. In addition, we identify genomic alterations associated with organ-specific metastases and employ them to stratify patients into various risk groups with propensities toward different metastatic organs. This organotropic stratification method achieves better prognostic value than the standard histological grading system in prostate cancer, especially in the identification of Bone-MFP and Liver-MFP subtypes, with potential in informing organ-specific examinations in follow-ups.

Treatment patterns and overall survival in HER2+ metastatic breast cancer at US community oncology practices

Aim: To describe real-world treatment patterns/outcomes among patients with HER2+ metastatic breast cancer (MBC). Materials & methods: Real-world treatments and overall survival (OS) were evaluated among adult women diagnosed with HER2+ MBC, with and without brain metastases (BMs), between June 1, 2012 and May 31, 2018 using electronic medical records from the Definitive Oncology Dataset. Results: Among 372 patients, 69% initiated first-line trastuzumab plus pertuzumab-based therapy; many therapy combinations were utilized in the second- to fourth-line. During follow-up (median 24.8 months), 18% of patients died (22% with and 16% without BMs). Mean OS was shortest among patients with BMs at MBC diagnosis in the third- and fourth-line. Conclusion: OS was poor, and no clear standard of care was observed among patients with HER2+ MBC progressing on trastuzumab-based therapies.

Clinical diagnosis and treatment of breast cancer with brain metastases and establishment of a prognostic model: a 10-year, single-center, real-world study of 559 cases

Background

This study involved a retrospective analysis of 559 metastatic breast cancer (MBC) patients with brain metastasis (BM). We aimed to establish the effectiveness of different preferred treatment methods and factors affecting overall survival following BM diagnosis (BMOS) and explore the feasibility of systemic treatment for MBC patients with BM.

Methods

Univariate and multivariate analyses were used to assess the efficacy of different preferred treatments and other factors associated with BMOS, and a nomogram was then established based on the results of the univariate analysis.

Results

Patients that initially received systemic drug therapy exhibited a clinical benefit rate (CBR) of 43.9% and an intracranial disease control rate (DCR) of 80.6%. The median time between BM diagnosis and the requirement for local intracranial treatment due to worsening disease status was 10.0 months for these patients (95% CI: 7.811–12.189 months). The median follow-up was 28.0 months, and the median BMOS was 16.0 months. Following BM diagnosis, the systemic drug treatment group had a better outcome than the local brain treatment group, with a respective median BMOS of 22.0 and 16.0 months (χ²=7.743, P=0.005). At the time of BM diagnosis, the median BMOS for patients without neurological symptoms diagnosed by regular screen was significantly longer than that of patients with neurological symptoms (18.0 vs. 13.0 months, respectively; χ²=11.371, P=0.001). Based on these analyses, a nomogram was constructed that incorporated disease-free survival (DFS), Karnofsky performance status (KPS), molecular subtype, number of extracranial metastases, BM location, number of BMs, neurological symptoms, and the preferred treatment approach, with a prediction probability (c-index) value of 0.76.

Conclusions

Systemic drug treatment has a beneficial effect on brain lesions, and effective treatment delays the need for local intracranial treatment. Cranial magnetic resonance imaging (MRI) screening can detect asymptomatic BM in MBC patients (particularly those with HER2−positive or triple-negative disease), offering these patients an opportunity to undergo systemic drug therapy, thereby prolonging their survival. To our knowledge, this is a well-fitted nomogram including current treatment and medical examination strategies to predict BMOS probability that offers value as an adjunct for the prognostic evaluation of MBC-BM patients.

Preservation of quality of life in patients with human epidermal growth factor receptor 2-positive metastatic breast cancer treated with tucatinib or placebo when added to trastuzumab and capecitabine (HER2CLIMB trial)

AIMS

In HER2CLIMB, tucatinib significantly improved progression-free and overall survival in patients with human epidermal growth factor receptor 2-positive (HER2+) metastatic breast cancer. We evaluated the impact of tucatinib on health-related quality of life (HR-QoL) in HER2CLIMB.

METHODS

Patients were randomised 2:1 to tucatinib or placebo combined with trastuzumab and capecitabine. Starting with protocol version 7, the EuroQol 5 Dimensions 5 Levels (EQ-5D-5L) questionnaire and EQ visual analogue scale (VAS) were administered at day 1 of cycle 1, every two cycles during cycles 3-9, every three cycles during cycle 12 and thereafter and at each patient's 30-day follow-up visit.

RESULTS

Among 364 patients eligible for HR-QoL assessment, 331 (91%) completed ≥1 assessment. EQ-VAS scores were similar for both arms at baseline and maintained throughout treatment. EQ-5D-5L scores were similar between the treatment arms, stable throughout therapy and worsened after discontinuing treatment. Risk of meaningful deterioration (≥7 points) on EQ-VAS was reduced 19% in the tucatinib vs. placebo arm (hazard ratio [HR]: 0.81; 95% confidence interval [CI]: 0.55, 1.18); the median (95% CI) time to deterioration was not reached in the tucatinib arm and was 5.8 months (4.3, -) in the placebo arm. Among patients with brain metastases (n = 164), risk of meaningful deterioration on EQ-VAS was reduced 49% in the tucatinib arm (HR: 0.51; 95% CI: 0.28, 0.93); the median (95% CI) time to deterioration was not reached in the tucatinib arm and was 5.5 months (4.2, -) in the placebo arm.

CONCLUSIONS

HR-QoL was preserved for patients with HER2+ metastatic breast cancer who were treated with tucatinib added to trastuzumab and capecitabine and maintained longer with tucatinib therapy than without it among those with brain metastases.

CLINICAL TRIAL REGISTRATION

NCT02614794.

US Food and Drug Administration regulatory updates in neuro-oncology

Objective

Contemporary management of patients with neuro-oncologic disease requires an understanding of approvals by the US Food and Drug Administration (FDA) related to nervous system tumors. To summarize FDA updates applicable to neuro-oncology practitioners, we sought to review oncology product approvals and Guidances that were pertinent to the field in the past year.

Methods

Oncology product approvals between January 1, 2020, and December 31, 2020, were reviewed for clinical trial outcomes involving tumors of the nervous system. FDA Guidances relevant to neuro-oncology were also reviewed.

Results

Five oncology product approvals described outcomes for nervous system tumors in the year 2020. These included the first regulatory approval for neurofibromatosis type 1: selumetinib for children with symptomatic, inoperable plexiform neurofibromas. Additionally, there were 4 regulatory approvals for non-central nervous system (CNS) cancers that described clinical outcomes for patients with brain metastases. These included the approval of tucatinib for metastatic human epidermal growth factor receptor 2 (HER2)-positive breast cancer including patients with brain metastases, brigatinib for anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer (NSCLC), and pralsetinib and selpercatinib for RET fusion-positive NSCLC. Finally, two FDA Guidances for Industry, “Cancer Clinical Trial Eligibility Criteria: Brain Metastases” and “Evaluating Cancer Drugs in Patients with Central Nervous System Metastases” were published to facilitate drug development for and inclusion of patients with CNS metastases in clinical trials.

Conclusions

Despite the challenges of the past year brought on by the COVID-19 pandemic, progress continues to be made in neuro-oncology. These include first-of-their-kind FDA approvals and Guidances that are relevant to the management of patients with nervous system tumors.

Economic burden of central nervous system metastases in human epidermal growth factor receptor 2-positive breast cancer

Aim: Compare healthcare resource utilization and costs among patients with HER2+ metastatic breast cancer (MBC) with and without central nervous system (CNS) metastases. Methods: Retrospective matched cohort study using IQVIA's PharMetrics^® Plus claims database. Results: Patients with CNS metastases (n = 753) experienced more outpatient, emergency room and inpatient visits versus controls (n = 753; all p < 0.05). In the post-index year, median total all-cause healthcare costs were significantly higher among patients with CNS metastases versus controls ($112,402 vs $50,835; p < 0.0001); outpatient costs primarily drove the cost differential. Conclusion: More effective therapies are needed that improve clinical outcomes and reduce economic burden associated with CNS metastases in patients with HER2+ MBC.

Current treatment options for HER2-positive breast cancer patients with brain metastases

Brain metastases (BMs) are frequently associated with HER2+ breast cancer (BC). Their management is based on a multi-modal strategy including both local treatment and systemic therapy. Despite therapeutic advance, BMs still have an adverse impact on survival and quality of life and the development of effective systemic therapy to prevent and treat BMs from HER2 + BC represents an unmet clinical need. Trastuzumab-based therapy has long been the mainstay of systemic therapy and over the last two decades other HER2-targeted agents including lapatinib, pertuzumab and trastuzumab emtansine, have been introduced in the clinical practice. More recently, novel agents such as neratinib, tucatinib and trastuzumab deruxtecan have been developed, with interesting activity against BMs. Further research is needed to better elucidate the best sequence of these agents and their combination with local treatment.

Prognosis of patients treated in a single neurosurgical reference centre for brain metastasis caused by dormant disseminated cells

Brain metastasis (BM) is a frequent complication of systemic cancer usually associated with poor prognosis. Survival depends on numerous factors, which complicates prognosis and treatment. It has been suggested that BM growing from previously dormant disseminated tumour cells (DTCs) may exhibit a milder phenotype than BM derived from continuously progressing metastatic cells; however, to the best of our knowledge, the prognosis of patients presenting with BM from dormant DTCs is unknown. The present study retrospectively compared survival data, collected from a single neurosurgical centre, between patients presenting with BM from previously dormant DTCs and patients with non-dormant BM. A total of 262 medical records were reviewed. In the univariate Cox regression analysis, the median survival of the dormant BM group was statistically longer than that of the non-dormant group (P=0.048); a trend towards a longer survival persisted after correcting for age, presence of breast cancer and treatment options (P=0.057), which are all factors known to influence outcome. The improved outcome of these patients could be considered in models for prognostication. Moreover, the development of therapies able to eradicate dormant DTCs could provide a new promising strategy to prolong the survival of patients with a favourable prognosis.

New brain metastases after whole-brain radiotherapy of initial brain metastases in breast cancer patients: the significance of molecular subtypes (KROG 16-12)

PURPOSE

To identify the risk factors leading to new brain metastases (BM) following brain-directed treatment for initial BM resulting from breast cancer (BC).

METHODS

In this multi-institutional study, 538 BC patients with available follow-up imaging after brain-directed treatment for initial BM were analyzed. Tumor molecular subtypes were classified as follows: hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-, n = 136), HER2-positive (HER2+, n = 253), or triple-negative BC (TNBC, n = 149).

RESULTS

In 37.4% of patients, new BM emerged at a median of 10.5 months after brain-directed treatment for initial BM. The 1-year actuarial rate of new BM for HR+/HER2-, HER2+, and TNBC were 51.9%, 44.0%, and 69.6%, respectively (p = 0.008). Initial whole-brain radiotherapy (WBRT) reduced new BM rates (22.5% reduction at 1 year, p < 0.001) according to molecular subtype (HR+/HER2-, 42% reduction at 1 year, p < 0.001; HER2+, 18.5%, p = 0.004; TNBC, 16.9%, p = 0.071). Multivariate analysis revealed an increased risk of new BM for the following factors: shorter intervals between primary BC diagnoses and BM (p = 0.031); TNBC (relative to HR+/HER2-) (p = 0.016); presence of extracranial metastases (p = 0.019); number of BM (>4) (p < 0.001); and BM in both tentorial regions (p = 0.045). Anti-HER2 therapy in HER2+ patients (p = 0.013) and initial use of WBRT (p < 0.001) significantly lowered new BM development.

CONCLUSIONS

Tumor molecular subtypes were associated with both rates of new BM development and the effectiveness of initial WBRT. Anti-HER2 therapy in HER2+ patients significantly lowered new BM occurrence.

Efficacy of lapatinib combined with capecitabine in patients with HER2-positive metastatic breast cancer in a real-world study

The aim of the present study was to determine the efficacy and safety of lapatinib-based treatment for patients with human epidermal growth factor receptor-2-positive (HER2⁺) metastatic breast cancer (MBC). The aim of the present real-world study was to investigate the medical records and follow-up information of 92 patients with HER2⁺ MBC who received a lapatinib-based regimen at the recurrent/metastatic stage, 78 of whom had been pretreated with trastuzumab. The results demonstrated that the median progression-free survival (PFS) was 5.8 months and the overall survival (OS) was 21.5 months, with an objective response rate (ORR) of 21.7%, disease control rate (DCR) of 87.0% and clinical benefit rate (CBR) of 47.8%. In the patients receiving a lapatinib-based regimen as first-, second- and third/later-line treatment, the median PFS was 10.4, 5.2 and 5.1 months (P=0.048), the median OS was 32.9, 29.1 and 13.0 months (P<0.001), the ORR was 38.9, 23.3 and 13.60%, and the DCR was 100, 83.3 and 84.1%, respectively. In the trastuzumab-resistant (n=71) and trastuzumab-sensitive (n=21) patients, the median PFS was 5.2 and 9.1 months (P=0.032), and the median OS was 21.4 and 44.3 months (P=0.003), respectively. In the patients who received lapatinib plus chemotherapy (n=68), the median PFS with lapatinib plus capecitabine (n=38) was 8.1 months, as compared with the 5.1 months with lapatinib plus other chemotherapy agents (n=30; P=0.005). The median PFS of 14 patients with brain metastases was 8.4 months, with an ORR of 35.7% and a DCR of 85.7%. Multivariate analysis revealed that the line of lapatinib-based treatment and its combination with capecitabine or a different agent were independent prognostic factors for the median PFS in patients with HER2⁺ MBC. A limited number of adverse events were observed with the combination of lapatinib and capecitabine. Therefore, the findings of the present study suggested that lapatinib-based treatment is effective in patients with HER2⁺ MBC (even in trastuzumab-pretreated patients), and the combination of lapatinib with capecitabine may be recommended due to its good efficacy, convenience and tolerability.

Central nervous system metastases in breast cancer: the impact of age on patterns of development and outcome

PURPOSE

The purpose of this study is to explore differences in the pattern and outcome of central nervous system (CNS) involvement in breast cancer by age at diagnosis.

METHODS

A retrospective database of a tertiary cancer center yielded 174 consecutive patients with breast cancer who were diagnosed with CNS metastases in 2006-2019. Data on histopathology, characteristics of CNS involvement, treatments, and survival (at three time points during the disease course) were compared between patients aged ≤ 45 and > 45 years. Pearson Chi-square or Fisher exact test and Kaplan-Meier survival curves with log-rank test were used for statistical analyses.

RESULTS

Study population was divided according to age at diagnosis of breast cancer. 65 patients were ≤ 45 years old and 109 patients > 45 years old. The younger group was characterized by longer median overall survival (117.1 months vs 88 months, p = 0.017) and longer interval between breast cancer diagnosis to development of CNS metastases (97.4 months vs 75.9 months, p = 0.026). Median survival after development of CNS disease was not significantly different (18.7 months vs 11.1 months, p = 0.341), although it was significantly longer in younger patients within the subgroup of patients with triple-negative disease (22.5 vs 7.9 months, p = 0.033). There were no between-group differences in number, location, and clinical presentation of CNS metastases or in systemic and CNS-directed treatment approaches.

CONCLUSION

While the presentation of CNS involvement was similar between the different age groups, younger patients had significantly longer CNS-free interval and longer overall survival, and for the subgroups of triple-negative patients, younger age at breast cancer diagnosis was associated with longer survival after diagnosis of CNS disease.

Local and systemic treatment for HER2-positive breast cancer with brain metastases: a comprehensive review

The management of human epidermal growth factor receptor (HER2)-positive breast cancer has improved over the past decade. However, despite improvements in systemic control, a substantial proportion of patients with advanced HER2-positive breast cancer suffer from central nervous system metastases and even intracranial progression after aggressive local treatment. There is paucity of data and no consensus on the systemic therapies for patients with intracranial progression. This review discusses both local and systemic treatments for HER2-positive breast cancer with brain metastases with a special focus on the response of central nervous system metastases. A recommended practical treatment algorithm to guide physicians in selecting the most appropriate anti-HER2 therapy for their patients is suggested.

Intracranial Efficacy and Survival With Tucatinib Plus Trastuzumab and Capecitabine for Previously Treated HER2-Positive Breast Cancer With Brain Metastases in the HER2CLIMB Trial

PURPOSE

In the HER2CLIMB study, patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer with brain metastases (BMs) showed statistically significant improvement in progression-free survival (PFS) with tucatinib. We describe exploratory analyses of intracranial efficacy and survival in participants with BMs.

PATIENTS AND METHODS

Patients were randomly assigned 2:1 to tucatinib or placebo, in combination with trastuzumab and capecitabine. All patients underwent baseline brain magnetic resonance imaging; those with BMs were classified as active or stable. Efficacy analyses were performed by applying RECIST 1.1 criteria to CNS target lesions by investigator assessment. CNS-PFS (intracranial progression or death) and overall survival (OS) were evaluated in all patients with BMs. Confirmed intracranial objective response rate (ORR-IC) was evaluated in patients with measurable intracranial disease.

RESULTS

There were 291 patients with BMs: 198 (48%) in the tucatinib arm and 93 (46%) in the control arm. The risk of intracranial progression or death was reduced by 68% in the tucatinib arm (hazard ratio [HR], 0.32; 95% CI, 0.22 to 0.48; P < .0001). Median CNS-PFS was 9.9 months in the tucatinib arm versus 4.2 months in the control arm. Risk of death was reduced by 42% in the tucatinib arm (OS HR, 0.58; 95% CI, 0.40 to 0.85; P = .005). Median OS was 18.1 versus 12.0 months. ORR-IC was higher in the tucatinib arm (47.3%; 95% CI, 33.7% to 61.2%) versus the control arm (20.0%; 95% CI, 5.7% to 43.7%; P = .03).

CONCLUSION

In patients with HER2-positive breast cancer with BMs, the addition of tucatinib to trastuzumab and capecitabine doubled ORR-IC, reduced risk of intracranial progression or death by two thirds, and reduced risk of death by nearly half. To our knowledge, this is the first regimen to demonstrate improved antitumor activity against BMs in patients with HER2-positive breast cancer in a randomized, controlled trial.

Proliferative Classification of Intracranially Injected HER2-positive Breast Cancer Cell Lines

HER2 is overexpressed in 25–30% of breast cancers, and approximately 30% of HER2-positive breast cancers metastasize to the brain. Although the incidence of brain metastasis in HER2-positive breast cancer is high, previous studies have been mainly based on cell lines of the triple-negative subtype, and the molecular mechanisms of brain metastasis in HER2-positive breast cancer are unclear. In the present study, we performed intracranial injection using nine HER2-positive breast cancer cell lines to evaluate their proliferative activity in brain tissue. Our results show that UACC-893 and MDA-MB-453 cells rapidly proliferated in the brain parenchyma, while the other seven cell lines moderately or slowly proliferated. Among these nine cell lines, the proliferative activity in brain tissue was not correlated with either the HER2 level or the HER2 phosphorylation status. To extract signature genes associated with brain colonization, we conducted microarray analysis and found that these two cell lines shared 138 gene expression patterns. Moreover, some of these genes were correlated with poor prognosis in HER2-positive breast cancer patients. Our findings might be helpful for further studying brain metastasis in HER2-positive breast cancer.

Specific Roles of HSP27 S15 Phosphorylation Augmenting the Nuclear Function of HER2 to Promote Trastuzumab Resistance

Trastuzumab (TZMB) is widely used as first line therapy for breast cancer (BC) patients overexpressing human epidermal growth factor receptor 2 (HER2). Despite its clinical benefits, many patients suffer from primary or secondary resistance to this drug within one year. As diverse molecular mechanisms occur contemporaneously during the resistance development, we focused on elucidating the role of heat shock protein 27 (HSP27) in TZMB-resistance, as this protein simultaneously regulates the function of diverse client molecules that are involved in the resistance mechanism. By extensively utilizing TZMB-refractory breast cancer cell lines transduced with diverse phosphovariants of HSP27, our study newly revealed that specific phosphorylation of HSP27 at S15 promoted its S78 phosphorylation and served as key mediator to promote direct interactions that increase the stability of HER2 and protein kinase B (AKT). This phosphorylation promoted nuclear translocation of HER2, enhancing the distinct nuclear function of HER2 that promoted AKT activation and cyclin D1 expression. Co-administration of TZMB and a functional inhibitor of HSP27, J2, significantly reduced the S15/78 phosphorylation of HSP27, which downregulated HER2 and its downstream signals, sensitizing TZMB-refractory cell, and JIMT1-xenograft mouse models to TZMB. Collectively, p-HSP27^S15 could serve as a valuable predictive marker and also a therapeutic target for TZMB-resistance.

FGFR aberrations increase the risk of brain metastases and predict poor prognosis in metastatic breast cancer patients

Background:

The survival status of patients with breast cancer and brain metastasis (BCBM) receiving current treatments is poor.

Method:

We designed a real-world study to investigate using patients’ clinical and genetic aberrations to forecast the prognoses of BCBM patients. We recruited 146 BCBM patients and analyzed their clinical features to evaluate the overall survival (OS). For genetic testing, 30 BCBM and 165 non-brain-metastatic (BM) metastatic breast cancer (MBC) patients from Hunan Cancer Hospital, and 86 BCBM and 1416 non-BM MBC patients from the Geneplus database who received circulating tumor DNA testing, were compared and analyzed.

Results:

Ki67 >14% and >3 metastatic brain tumors were significant risk factors associated with poor OS, while chemotherapy and brain radiotherapy were beneficial factors for better OS. Compared with non-BM MBC patients, BCBM patients had more fibroblast growth factor receptor (FGFR) aberrations. The combination of FGFR, TP53 and FLT1 aberrations plus immunohistochemistry HER2-positive were associated with an increased risk of brain metastasis (AUC = 77.13%). FGFR aberration alone was not only a predictive factor (AUC = 67.90%), but also a significant risk factor for poor progression-free survival (Logrank p = 0.029). FGFR1 aberration was more frequent than other FGFR family genes in BCBM patients, and FGFR1 aberration was significantly higher in BCBM patients than non-BM MBC patients. Most FGFR1-amplified MBC patients progressed within 3 months of the late-line (>2 lines) treatment.

Conclusion:

A group of genetic events, including FGFR, TP53 and FLT1 genetic aberrations, and HER2-positivity, forecasted the occurrence of BM in breast cancers. FGFR genetic aberration alone predicted poor prognosis.

Expression of angiopoietin-like 4 fibrinogen-like domain (cANGPTL4) increases risk of brain metastases in women with breast cancer

Background: Brain metastases challenge daily clinical practice, and the mechanisms by which cancer cells cross the blood-brain barrier remain largely undeciphered. Angiopoietin-like 4 (ANGPTL4) proteolytic fragments have controversial biological effects on endothelium permeability. Here, we studied the link between ANGPTL4 and the risk of brain metastasis in cancer patients.

Materials and Methods: From June 2015 to June 2016, serum samples from 113 cancer patients were prospectively collected, and ANGPTL4 concentrations were assessed. Using a murine model of brain metastases, we investigated the roles of nANGPTL4 and cANGPTL4, the two cleaved fragments of ANGPTL4, in the occurrence of brain metastases.

Results: An ANGPTL4 serum concentration over 0.1 ng/mL was associated with decreased overall-survival. Multivariate analyses found that only breast cancer brain metastases were significantly associated with elevated ANGPTL4 serum concentrations.

4T1 murine breast cancer cells were transfected with either nANGPTL4- or cANGPTL4-encoding cDNAs. Compared to mice injected with wild-type 4T1 cells, mice injected with nANGPTL4 cells had shorter median survival (p < 0.05), while mice injected with cANGPTL4 had longer survival (p < 0.01). On tissue sections, compared to wild-type mice, mice injected with nANGPTL4 cells had significantly larger surface areas of lung metastases (p < 0.01), and mice injected with cANGPTL4 had significantly larger surface areas of brain metastases (p < 0.01).

Conclusions: In this study, we showed that a higher expression of Angiopoietin-like 4 Fibrinogen-Like Domain (cANGPTL4) was associated with an increased risk of brain metastases in women with breast cancer.

Lapatinib in combination with capecitabine versus continued use of trastuzumab in breast cancer patients with trastuzumab-resistance: a retrospective study of a Chinese population

BACKGROUND

The efficacy and safety of lapatinib plus capecitabine (LC or LX) versus trastuzumab plus chemotherapy in patients with HER-positive metastatic breast cancer who are resistant to trastuzumab is unknown.

METHODS

We retrospectively analyzed data from breast cancer patients who began treatment with regimens of lapatinib plus capecitabine (LC or LX) or trastuzumab beyond progression (TBP) at eight hospitals between May 2010 and October 2017.

RESULTS

Among 554 patients who had developed resistance to trastuzumab, the median PFS (progression free survival) was 6.77 months in the LX group compared with 5.6 months in the TBP group (hazard ratio 0.804; 95% CI, 0.67 to 0.96; P = 0.019). The central nervous system progression rate during treatment was 5.9% in the LX group and 12.5% in the TBP group (P = 0.018).

CONCLUSION

The combination of lapatinib and capecitabine showed a prolonged PFS relative to TBP in patients who had progressed on trastuzumab.

Tucatinib, Trastuzumab, and Capecitabine for HER2-Positive Metastatic Breast Cancer

BACKGROUND

Patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer who have disease progression after therapy with multiple HER2-targeted agents have limited treatment options. Tucatinib is an investigational, oral, highly selective inhibitor of the HER2 tyrosine kinase.

METHODS

We randomly assigned patients with HER2-positive metastatic breast cancer previously treated with trastuzumab, pertuzumab, and trastuzumab emtansine, who had or did not have brain metastases, to receive either tucatinib or placebo, in combination with trastuzumab and capecitabine. The primary end point was progression-free survival among the first 480 patients who underwent randomization. Secondary end points, assessed in the total population (612 patients), included overall survival, progression-free survival among patients with brain metastases, confirmed objective response rate, and safety.

RESULTS

Progression-free survival at 1 year was 33.1% in the tucatinib-combination group and 12.3% in the placebo-combination group (hazard ratio for disease progression or death, 0.54; 95% confidence interval [CI], 0.42 to 0.71; P<0.001), and the median duration of progression-free survival was 7.8 months and 5.6 months, respectively. Overall survival at 2 years was 44.9% in the tucatinib-combination group and 26.6% in the placebo-combination group (hazard ratio for death, 0.66; 95% CI, 0.50 to 0.88; P = 0.005), and the median overall survival was 21.9 months and 17.4 months, respectively. Among the patients with brain metastases, progression-free survival at 1 year was 24.9% in the tucatinib-combination group and 0% in the placebo-combination group (hazard ratio, 0.48; 95% CI, 0.34 to 0.69; P<0.001), and the median progression-free survival was 7.6 months and 5.4 months, respectively. Common adverse events in the tucatinib group included diarrhea, palmar-plantar erythrodysesthesia syndrome, nausea, fatigue, and vomiting. Diarrhea and elevated aminotransferase levels of grade 3 or higher were more common in the tucatinib-combination group than in the placebo-combination group.

CONCLUSIONS

In heavily pretreated patients with HER2-positive metastatic breast cancer, including those with brain metastases, adding tucatinib to trastuzumab and capecitabine resulted in better progression-free survival and overall survival outcomes than adding placebo; the risks of diarrhea and elevated aminotransferase levels were higher with tucatinib. (Funded by Seattle Genetics; HER2CLIMB ClinicalTrials.gov number, NCT02614794.).

Three-institution study on applicability of initial brain metastasis velocity for breast cancer brain metastasis patients undergoing stereotactic radiosurgery

PURPOSE

This study aimed to validate whether the recently-proposed prognostic grading system, initial brain metastasis velocity (iBMV), is applicable to breast cancer patients receiving stereotactic radiosurgery (SRS). We focused particularly on whether this grading system is useful for patients with all molecular types, i.e., positive versus negative for EsR, PgR and HER2.

METHODS AND MATERIALS

This was an institutional review board-approved, retrospective cohort study using our database, prospectively accumulated at three gamma knife institutes, during the 20-year-period since 1998. We excluded patients for whom the day of primary cancer diagnosis was not available, had synchronous presentation, lacked information regarding molecular types, and/or had received pre-SRS radiotherapy and/or surgery. We ultimately studied 511 patients categorized into two classes by iBMV scores, i.e., < 2.00 and ≥ 2.00.

RESULTS

The median iBMV score for the entire cohort was 0.97 (IQR 0.39-2.84). Median survival time (MST) in patients with iBMV < 2.00, 15.9 (95% CI 13.0-18.6, IQR 7.5-35.5) months, was significantly longer than that in patients with iBMV ≥ 2.00, 8.2 (95% CI 6.8-9.9, IQR 3.9-19.4) months (HR 1.582, 95% CI: 1.308-1.915, p < 0.0001). The same results were obtained in patients with EsR (-), PgR (-), HER2 (+) and HER2 (-) cancers, while MSTs did not differ significantly between iBMV < 2.00 vs ≥ 2.00 in patients with EsR (+) and PgR (+) cancers.

CONCLUSIONS

This system was clearly shown to be applicable to breast cancer patients with SRS-treated BMs. However, this system is not applicable to patients with hormone receptor (+) breast cancer.