WOODCLIFF LAKE, N.J., Sept. 28, 2015 /PRNewswire/ -- Eisai Inc. announced today that the U.S. Food and Drug Administration (FDA) has accepted for review the supplemental New Drug Application (sNDA) for eribulin mesylate (eribulin) being evaluated for patients with inoperable soft tissue sarcoma (leiomyosarcoma and liposarcoma) who have received prior chemotherapy for advanced or metastatic disease. The sNDA was granted Priority Review status.

According to the FDA, Priority Review designation is granted to applications for drugs which, if approved, have the potential to provide "significant improvements in the safety or effectiveness of the treatment, prevention, diagnosis, or prevention of serious conditions when compared to standard applications."

Eribulin, discovered and developed by Eisai, is a microtubule dynamics inhibitor. Sold under the brand name Halaven^®, it is indicated for patients with metastatic breast cancer who have received at least two chemotherapeutic regimens for the treatment of metastatic disease, and whose prior therapy should have included an anthracycline and a taxane in either the adjuvant or metastatic setting.

Soft tissue sarcomas account for less than 1% of all malignant tumors, but they are life threatening and pose a significant challenge for diagnosis and treatment as there are more than 50 subtypes with unique clinical, prognostic and therapeutic features.

"Advanced soft tissue sarcoma is very difficult to treat, so we are excited to be one step closer to potentially bringing an additional treatment option to patients in need," said Kenichi Nomoto, Ph.D., President, Oncology Product Creation Unit, Eisai Product Creation Systems.

About Soft Tissue Sarcoma
Soft tissue sarcomas are cancers that develop from cells in the soft, supporting tissues of the body such as fat, muscle, nerves, fibrous tissues and blood vessels. The annual incidence of soft tissue sarcoma is approximately 30 cases per million of the population – equivalent to less than 1% of all malignant tumors. Soft tissue sarcomas are mostly diagnosed in early-stage or localized disease, and many patients are amenable to complete surgical removal, yet relapse rates can be as high as 50% and outcomes for patients with advanced disease are poor, with median survival around 1 year or less.

Leiomyosarcoma is one of the more common types of sarcoma to develop in adults. These tumors develop from cells called smooth muscle and can start anywhere in the body. Liposarcoma (adipocytic sarcoma) refers to tumors that arise from fat cells and can also occur anywhere in the body. Leiomyosarcomas and liposarcomas make up approximately 30% of all cases of soft tissue sarcoma.

About Halaven^® (eribulin mesylate) Injection
Halaven is not indicated for patients with advanced soft tissue sarcoma.

Halaven is indicated for patients with metastatic breast cancer who have received at least two chemotherapeutic regimens for the treatment of metastatic breast cancer. Prior therapy should have included an anthracycline and a taxane in either the adjuvant or metastatic setting. 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 with a distinct binding profile. Based on in vitro studies, eribulin exerts its effect via a tubulin-based antimitotic mechanism ultimately leading to apoptotic cell death after prolonged and irreversible mitotic blockage.

Important Safety Information

Neutropenia

• Monitor complete blood 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 longer than 7 days
• Severe neutropenia (ANC <500/mm³) lasting more than 1 week occurred in 12% (62/503) of patients. Patients 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
• Grade 3 and Grade 4 neutropenia occurred in 28% and 29%, respectively, of patients who received Halaven. Febrile neutropenia occurred in 5% of patients and two patients (0.4%) died from complications

Peripheral Neuropathy

• Patients should be monitored closely for signs of peripheral motor and sensory neuropathy
• Grade 3 peripheral neuropathy occurred in 8% of patients, and Grade 4 in 0.4% of patients who received Halaven. Delay administration of Halaven until resolution to Grade 2 or less
• Neuropathy lasting more than 1 year occurred in 5% of patients. Twenty-two percent of patients developed a new or worsening neuropathy that had not recovered within a median follow-up duration of 269 days (range 25-662 days)
• Peripheral neuropathy (5%) was the most common adverse reaction resulting in discontinuation

Pregnancy Category D

• Halaven is expected to cause fetal harm when administered to a pregnant woman and patients should be advised of these risks

QT Prolongation

• In an uncontrolled ECG study in 26 patients, QT prolongation was observed on Day 8, independent of Halaven concentration, with no prolongation on Day 1. ECG monitoring is recommended for patients with congestive heart failure; bradyarrhythmias; concomitant use of drugs that prolong QT interval, including Class Ia and III antiarrhythmics; and electrolyte abnormalities
• Correct hypokalemia or hypomagnesemia prior to initiating Halaven^® and monitor electrolytes periodically during therapy. Avoid in patients with congenital long QT syndrome

Hepatic and Renal Impairment

• For patients with mild (Child-Pugh A) or moderate (Child-Pugh B) hepatic and/or moderate or severe (CrCl 15-49 mL/min) renal impairment, a reduction in starting dose is recommended

Most Common Adverse Reactions

• Most common adverse reactions (≥25%) reported in patients receiving Halaven were neutropenia (82%), anemia (58%), asthenia/fatigue (54%), alopecia (45%), peripheral neuropathy (35%), nausea (35%), and constipation (25%)
• The most common serious adverse reactions reported in patients receiving Halaven were febrile neutropenia (4%) and neutropenia (2%)

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

About Eisai Inc.
At Eisai Inc., human health care is our goal. We give our first thoughts to patients and their families, and helping to increase the benefits health care provides. As the U.S. pharmaceutical subsidiary of Tokyo-based Eisai Co., Ltd., we have a passionate commitment to patient care that is the driving force behind our efforts to help address unmet medical needs. We are a fully integrated pharmaceutical business with discovery, clinical, manufacturing and marketing capabilities. Our key areas of commercial focus include oncology and specialty care (Alzheimer's disease, epilepsy and metabolic disorders). To learn more about Eisai Inc., please visit us at www.eisai.com/US.  

Eisai Inc. has affiliates that are part of a global product creation organization that includes R&D facilities in Massachusetts, New Jersey and Pennsylvania, as well as a global demand chain organization that includes facilities in Maryland and North Carolina. Eisai's global areas of R&D focus include neuroscience; oncology; metabolic disorders; vascular, inflammatory and immunological reaction; and antibody-based programs.

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