Phase I study of LY573636-sodium, an acylsulfonamide anti-cancer compound with a novel mechanism of action, administered as 24-hour continuous infusion in patients with advanced solid tumors

2515 Background: LY573636-sodium (hereafter referred to as LY573636) is a novel anti-cancer compound that induces apoptosis by a mitochondrial-mediated mechanism. Methods: A phase I study was conducted to determine the maximum tolerated dose (MTD) and pharmacokinetic (PK) profile of LY573636 administered as an intravenous infusion over 2 hours every 21 days. Results: 53 patients (pts) were enrolled on study, 16 males, 37 females, with a median age of 58 (range: 18–83). LY573636 was dose-escalated using a flat dosing paradigm in the first 34 patients (range 100 mg to 2400 mg). PK analysis of this cohort revealed that LY573636 had a low total plasma clearance (CL = 0.02L/hr) and terminal elimination half-life of approximately 340 hours due to high-albumin binding (∼99%). The dose limiting toxicity (DLT) for the flat dose escalation was bone marrow (BM) suppression, which included CTC (ver2) grade 3/4 thrombocytopenia/neutropenia. In some patients, significant BM suppression occurred in cycle 2 and later, at...