WOODCLIFF LAKE, N.J., May 18, 2021 /PRNewswire/ -- Eisai today announced results from a real-world study assessing treatment patterns and clinical outcomes with HALAVEN^® (eribulin mesylate) injection as a third-line therapy or greater in patients with metastatic breast cancer (mBC), including the triple-negative breast cancer (TNBC) subtype. These data were recently published in Advances in Therapy.

The study was a retrospective, multi-site patient chart review study conducted across oncology practices in the United States and included mBC patients (n=513) who had initiated treatment with HALAVEN, as per U.S. Prescribing Information, between 2011 and 2017. Data were extracted by prescribing physicians from individual patients' electronic health records and captured via an electronic case report form. All patient data were de-identified prior to analysis. Clinical endpoints assessed included provider-reported objective response rate (ORR), clinical benefit rate (CBR), progression-free survival (PFS) and overall survival (OS) in all patients and separately for those with TNBC subtype.

The median age of patients was 59 years at initiation of HALAVEN therapy, and 61% of the patients had Eastern Cooperative Oncology Group (ECOG) status 0 or 1. Within the overall mBC cohort, 50% (n=256) had TNBC. A greater proportion of patients with TNBC were treated with HALAVEN in the 3^rd line (87.9%) compared with the overall patient cohort (78%), with the remainder treated in the 4^th line or later. At the time of data cut-off, 96.9% (n=497) in the overall patient cohort and 96.9% (n=248) in the TNBC subgroup had discontinued HALAVEN treatment. Of the patients who discontinued treatment with HALAVEN, disease progression was reported as the main reason for 78.1% and 84.3% of patients in the overall cohort and TNBC subtype, respectively.   

In the overall mBC cohort, median PFS was 6.1 months (95% CI: 5.8-6.6). In the TNBC subgroup, median PFS was 5.8 months (95% CI: 5.1-6.4). Median OS was 10.6 months (95% CI: 9.9-11.7) in the overall mBC cohort, and 9.8 months (95% CI: 8.6-11.0) in the TNBC subgroup. In the overall mBC cohort, ORR was 54.4% (95% CI: 50.1-58.7), and 55.1% (95% CI: 49.0-61.2) in the TNBC subgroup. In the overall mBC cohort, CBR was 56.7% (95% CI: 52.4-61.0), and 57.4% (95% CI: 51.4-63.5) in the TNBC subgroup.

One of the limitations of this study is that detailed safety data were not collected. In addition, the treatment patterns reflected in the study might represent only the practices of physicians who consented to participate in the study. Loss to follow-up during the study period may have occurred, if patients transferred care to other providers and centers.

"For oncologists and people living with metastatic breast cancer, these data provide insights into HALAVEN real-world practice," said Dr. Takashi Owa, Vice President, Chief Medicine Creation Officer and Chief Discovery Officer, Oncology Business Group at Eisai. "We have remained committed to the continued data generation for HALAVEN, both in the real-world setting and in translational research related to mBC, to drive our continued innovation for difficult-to-treat diseases like mBC."

HALAVEN was approved by the U.S. FDA in November 2010 for the treatment of patients with mBC who have previously received at least two chemotherapeutic regimens for the treatment of metastatic disease. Prior therapy should have included an anthracycline and a taxane in either the adjuvant or metastatic setting.

About Metastatic Breast Cancer & Triple Negative Breast Cancer
Metastatic breast cancer (mBC) is an advanced stage of the disease that occurs when cancer spreads beyond the breast to other parts of the body. In 2020, an estimated 276,480 women will be diagnosed with breast cancer in the United States and an estimated 42,170 women will die from the disease. It is estimated that 20-30% of people with early stage breast cancers will go on to develop metastatic disease, and approximately 6-10% of women with breast cancer will have metastatic disease at the time of diagnosis. Metastatic breast cancer has a poor prognosis compared to non-metastatic breast cancer. The estimated 5-year relative survival rate for women with mBC compared to women with non-metastatic breast cancers is 28% versus 99%, respectively.

Triple-negative breast cancer (TNBC) is a subtype of breast cancer in which cancer cells lack the expression of both estrogen and progesterone receptors, which are commonly found in breast cancer, as well as the protein called human epidermal growth factor (HER2). TNBC accounts for 15-20% of all breast cancers. Distant recurrence and mortality in TNBC is significantly worse than other subtypes and is often associated with a worse prognosis. Patients with breast cancer along with metastatic estrogen and progesterone receptor (ER/PR) negative and human epidermal growth factor receptor 2 (HER2)-negative tumors are referred to as having metastatic triple-negative breast cancer (mTNBC) disease.

About HALAVEN^® (eribulin mesylate) Injection
HALAVEN (eribulin mesylate) injection is indicated for the treatment of patients with metastatic breast cancer (mBC) who have previously received at least 2 chemotherapeutic regimens for the treatment of metastatic disease. Prior therapy should have included an anthracycline and a taxane in either the adjuvant or metastatic setting.

Discovered and developed by Eisai, eribulin is a synthetic analog of halichondrin B, a natural product that was isolated from the marine sponge Halichondria okadai. First in the halichondrin class, eribulin is a microtubule dynamics inhibitor. Eribulin is believed to work primarily via a tubulin-based mechanism that causes prolonged and irreversible mitotic blockage, ultimately leading to apoptotic cell death. Additionally, in preclinical studies of human breast cancer, eribulin demonstrated complex effects on the tumor biology of surviving cancer cells, including increases in vascular perfusion resulting in reduced tumor hypoxia, and changes in the expression of genes in tumor specimens associated with a change in phenotype, promoting the epithelial phenotype, opposing the mesenchymal phenotype. Eribulin has also been shown to decrease the migration and invasiveness of human breast cancer cells.

Important Safety Information

Warnings and Precautions

Neutropenia: Severe neutropenia (ANC <500/mm3) lasting >1 week occurred in 12% of patients with mBC. Febrile neutropenia occurred in 5% of patients with mBC and 2 patients (0.4%) died from complications. Patients with mBC with elevated liver enzymes >3 × ULN and bilirubin >1.5 × ULN experienced a higher incidence of Grade 4 neutropenia and febrile neutropenia than patients with normal levels. Monitor complete blood cell counts prior to each dose, and increase the frequency of monitoring in patients who develop Grade 3 or 4 cytopenias. Delay administration and reduce subsequent doses in patients who experience febrile neutropenia or Grade 4 neutropenia lasting >7 days.

Peripheral Neuropathy: Grade 3 peripheral neuropathy occurred in 8% of patients with mBC (Grade 4=0.4%) and 22% developed a new or worsening neuropathy that had not recovered within a median follow-up duration of 269 days (range 25-662 days). Neuropathy lasting >1 year occurred in 5% of patients with mBC. Patients should be monitored for signs of peripheral motor and sensory neuropathy. Withhold HALAVEN in patients who experience Grade 3 or 4 peripheral neuropathy until resolution to Grade 2 or less. 

Embryo-Fetal Toxicity: HALAVEN can cause fetal harm when administered to a pregnant woman. Advise females of reproductive potential to use effective contraception during treatment with HALAVEN and for at least 2 weeks following the final dose. Advise males with female partners of reproductive potential to use effective contraception during treatment with HALAVEN and for 3.5 months following the final dose.

QT Prolongation: Monitor for prolonged QT intervals in patients with congestive heart failure, bradyarrhythmias, drugs known to prolong the QT interval, and electrolyte abnormalities. Correct hypokalemia or hypomagnesemia prior to initiating HALAVEN and monitor these electrolytes periodically during therapy. Avoid in patients with congenital long QT syndrome.

Adverse Reactions
In patients with mBC receiving HALAVEN, the most common adverse reactions (≥25%) were neutropenia (82%), anemia (58%), asthenia/fatigue (54%), alopecia (45%), peripheral neuropathy (35%), nausea (35%), and constipation (25%). Febrile neutropenia (4%) and neutropenia (2%) were the most common serious adverse reactions. The most common adverse reaction resulting in discontinuation was peripheral neuropathy (5%).

Use in Specific Populations
Lactation: Because of the potential for serious adverse reactions in breastfed infants from eribulin mesylate, advise women not to breastfeed during treatment with HALAVEN and for 2 weeks after the final dose.

Hepatic and Renal Impairment: A reduction in starting dose is recommended for patients with mild or moderate hepatic impairment and/or moderate or severe renal impairment.

For more information about HALAVEN, click here for the full Prescribing Information.

HALAVEN^® is a registered trademark used by Eisai Inc. under license from Eisai R&D Management Co., Ltd.

About Eisai
Eisai is a leading global research and development-based pharmaceutical company headquartered in Japan, with approximately 10,000 employees worldwide. We define our corporate mission as "giving first thought to patients and their families and to increasing the benefits health care provides," which we call our human health care (hhc) philosophy. We strive to realize our hhc philosophy by delivering innovative products in therapeutic areas with high unmet medical needs, including Oncology and Neurology. In the spirit of hhc, we take that commitment even further by applying our scientific expertise, clinical capabilities and patient insights to discover and develop innovative solutions that help address society's toughest unmet needs, including neglected tropical diseases and the Sustainable Development Goals.

For more information about Eisai, please visit www.eisai.com (for global), us.eisai.com (for U.S.) or www.eisai.eu (for Europe, Middle East, Africa), and connect with us on Twitter (U.S. and global) and LinkedIn (for U.S.).

SOURCE Eisai Inc.