510P Safety and efficacy of eribulin mesylate in patients with advanced soft tissue sarcoma in daily practice

Abstract

Background Eribulin is a microtubule inhibitor approved for treating all types of advancedsofttissuesarcomas(STSs)inJapanasofFebruary2016.Dataoferibulinuse in STS other than adipocytic sarcoma (ADI) and leiomyosarcoma (LMS) are limited, thereforeweassessedthesafetyandactivityoferibulininSTSsincludingthoseother than ADI and LMS patients in practical clinic. Methods We retrospectively analyzed patients with STS who received eribulin monotherapy after approval at National Cancer Center Hospital outside of clinical trials. Eribulin was administered intravenously at a dose of 1.4mg/m2 on days 1 and 8 in a 21-day cycle. We investigated the safety and efficacy of eribulin monotherapy in three different groups: ADI, LMS and others (OTH). We assessed treatment toxicity based on CTCAE v4.0, and evaluated tumor response according to RECIST 1.1. Results A total of 23 patients were assessed (ADI; 10 pts, LMS; 3 pts, OTH; 10 pts). Histological subtypes included in OTH were: alveolar rhabdomyoma, angiosarcoma, malignant peripheral nerve sheath tumor, malignant spindle cell neoplasm, myoepithelioma-like tumor of the vulvar region, desmoplastic small round cell, intimal sarcoma, and undifferentiated pleomorphic sarcoma. The median number of previous chemotherapy lines was 3 (range 1-7). Median age was 55 years (range 27-76). The most common primary site was retroperitoneal space (35%), and the most common metastatic site was lung (39%). Median follow-up period was 108 days. At the time of analysis, 18 patients (ADI; 10 pts, LMS; 3 pts and OTH 5 pts) were alive, and 5 patients (ADI; 3 pts, LMS; 1 pt, OTH; 1 pt) were still continuing eribulin. No patients achieved a complete response or a partial response. Six patients had stable disease (ADI; 5pts, LMS; 0 pts and OTH; 1 pt). The most common adverse event was anemia (56%), followed by neutropenia (43%) and fever (43%). The most common grade 3/4 toxicity was neutropenia (43%). One death occurred within 30 days of the last dose due to disease progression. Conclusions: Routine use of eribulin in advanced STSs including OTH was safe and well-tolerated. Further investigation is needed to clarify the efficacy in the clinical setting. Legal entity responsible for the study National Cancer Center Hospital Funding N/A Disclosure All authors have declared no conflicts of interest.