A non-comparative phase II study of bendamustine hydrochloride in patients with pretreated soft tissue sarcoma (German Sarcoma Group-AIO 001)

Abstract

9525 Background: To assess the efficacy and safety of bendamustine hydrochloride, a nucleoside analogue with alkylating activity, in patients with adult type soft tissue sarcoma (STS) who have failed anthracyline-based chemotherapy. Methods: Pts with a ECOG performance status 0–2, measurable disease and adequate organ functions were eligible. All patients had inoperable locally advanced or metastatic disease and had progressive disease during or after first-line chemotherapy prior to study entry. Bendamustine was administered at a dose of 100 mg/sqm on day 1 and 2 every four weeks for a maximum of 6 cycles with tumour assessment every two cycles. The primary endpoint was overall response rate as defined by RECIST. The secondary endpoint was toxicity. A two-stage design was used (1st step: 14 pts, at least 1 PR in order to succeed with 2nd step; p0 = 5%, p1 = 25%, alpha = beta = 0.1). Results: 32 patients, median age 56 yrs (range, 18–74) with STS were recruited (3 pts not evaluable for efficacy analysis). In general the drug was well tolerated. Grade 3 toxicity was granulocytopenia in 9% and febrile neutropenia/fever in 3% of pts. No toxic death was seen in a total of 89 cycles administered. A single pt experienced a clinically significant allergic reaction (3%). Anti-tumour activity: 1 confirmed partial response (3%). A further 10 patients had progression arrest by cycle two (34%). Conclusions: The confirmed objective response rate is low. However, the incidence of progression arrest in pretreated adult type STS is in the range of other agents considered active in STS. The observed toxicity profile is favorable. Further investigation in STS appears warranted. No significant financial relationships to disclose.