Phase Ib/II study of INNO-206 (EMCH-doxorubicin) in patients with soft tissue sarcoma.

Abstract

10036 Background: The safety and preliminary tumor response of a doxorubicin conjugate, INNO-206, was evaluated primarily in patients with metastatic STS who progressed on prior chemotherpy. INNO-206 consists of doxorubicin attached to an acid-sensitive linker that binds covalently to cysteine-34 in circulating albumin. Methods: INNO-206 was administered IV at doses of either 230, 350 and 450 mg/m2 (165, 260 and 325 mg/m2 dox. eq.) every 21 days for up to 8 consecutive cycles. Subsequent dose levels were administered if < 2/5 or 4/8 patients experienced a non-hematological dose-limiting toxicity during Cycle 1. Tumor response was monitored every other month and treatment continued until tumor progression or unacceptable toxicity. Standard safety monitoring was performed and cardiac function was followed periodically using MUGA or cardiac ultrasound. Results: As of January 11, 2012, 25 patients were entered in the study. 21/25 patients had STS of various types. Of the 5 patients treated at 230 mg/m2 INNO-206, 1 subject had grade 3 fatigue and acid reflux. Of the initial 5 patients entered at the 350 mg/m2 dose, no individuals experienced a grade 3 or 4 non-hematological toxicity during cycle 1. 2 patients treated at the 450 mg/m2 dose developed grade 3 oral mucositis during cycle 1. No patient exhibited cardiotoxicity as determined by MUGA or cardiac ultrasound. The MTD was determined to be 350 mg/m2 INNO-206 (260 mg/m2 dox.eq.). 15 more patients were entered at this dose (total of 20 patients). Of the 16 patients with STS, 3 objective partial responses (one of whom received prior doxorubicin) are ongoing as well as 10 patients with stable disease (range 2-7 months). 1 patient had progressive disease at the first evaluation. 2 patients died within the first cycle, one due to progressive disease and the other due to sepsis. Conclusions: INNO-206 is an active drug for the treatment of patients with advanced STS who have failed prior chemotherapy. Cumulative doses of 2000 mg/m2 of doxorubicin equivalents have been achieved, which is over 3 1/2 x the peak cumulative dose of standard doxorubicin. Adverse events are primarily hematological and no cardiotoxicity has been observed.