Eisai Phase 3 trial of eribulin meets primary endpoint in patients with advanced soft tissue sarcoma

Eisai Inc. announced today the results of its Phase 3 trial (Study 309), which showed that eribulin met the study's primary endpoint evaluating overall survival in patients who had advanced leiomyosarcoma (LMS) or adipocytic sarcoma (ADI), two types of advanced soft tissue sarcoma. These data will be presented at the 51^st Annual Meeting of the American Society of Clinical Oncology (ASCO) in Chicago as part of the ASCO press conference on Saturday, May 30, and also in an oral session on Monday, June 1 at 3:48 p.m. CT (Abstract No. LBA10502).

"For patients with advanced soft tissue sarcoma, outcomes are often poor and there are limited treatment options," said Patrick Schöffski, MD, MPH, Department of General Medical Oncology, University Hospitals Leuven, Belgium. "These results are important in a disease where so few treatment options exist."

Data from Study 309 demonstrated patients treated with eribulin (n=228) experienced a median overall survival of 13.5 months compared to 11.5 months for those treated with dacarbazine (n=224) (HR 0.768; 95% CI 0.618-0.954; p=0.017). The secondary endpoints of the Phase 3 trial (Study 309) included progression-free rate (PFR) at week 12 and progression-free survival (PFS). While there was a numerical difference in PFR at week 12 between the eribulin and dacarbazine arms (33% vs 29%), this was not statistically significant. Median PFS was 2.6 months in both arms.

Safety was an additional secondary endpoint of Study 309. Data demonstrated eribulin had a toxicity profile consistent with prior experience, with no unexpected or new safety findings. In this study, the most frequent treatment-emergent adverse events in the eribulin arm were neutropenia, fatigue, nausea, alopecia and constipation.

Study 309 was a randomized, open-label, multicenter trial of eribulin mesylate 1.4mg/m² administered intravenously (IV) on days one and eight of a 21-day cycle versus dacarbazine IV on day one, every 21 days (dose range of 850 mg/m² to 1,200 mg/m²) to patients (n=452) with locally advanced or recurrent and/or metastatic LMS or ADI who had disease progression following two standard therapies, one of which must have been an anthracycline (unless contraindicated).

"Study 309 represents the first investigational Phase 3 trial in patients with soft tissue sarcoma to demonstrate an overall survival benefit compared with an active agent," said Kenichi Nomoto, Ph.D., President, Oncology Product Creation Unit at Eisai Inc. "We are proud of our ongoing research efforts that may expand the value of existing therapies to address the unmet medical needs of patients, especially those with rare and orphan cancers, across the oncology spectrum."

The information discussed in this release presents an investigational use for an FDA-approved product. It is not intended to convey conclusions about efficacy and safety. There is no guarantee that the investigational use of this FDA-approved product will successfully complete clinical development or gain FDA approval.