3067 Background: ME-143, a second generation isoflavone-derived compound, specifically binds tNOX, shifting the ceramide-S1P equilibrium and resulting in prompt apoptosis via pleotrophic caspase activation. A first generation compound, phenoxodiol (PXD), showed promising phase II activity with cisplatin in ovarian cancer. ME-143 is broadly active against human cancers in both in vitro and in vivo models, with IC50’s 1-2 logs lower than PXD. Toxicology studies up to 140mg/kg (human dose equivalent ~23mg/kg) showed no STD level. The only significant findings were dose dependent hypospermia and testicular atrophy in rats. We report clinical and PK results from the first-in-human phase I study. Methods: A 3+3 dose escalation design was used with 4 dose cohorts: 2.5, 5, 10, and 20mg/kg IV over 30 minutes weekly times 3, followed by a 1 week break, and then continuous weekly dosing in patients with advanced solid tumors. Dense PK sampling was performed at 0, 5, 10, 20, 30, 60, 90, 120, 180, 240, 300, 360 minutes, and 24 hours post-infusion day 1 and 15 of the first treatment cycle. Results: To date, 9 patients have been enrolled, 3 in each of the first 3 cohorts. Median time on treatment is 56 days (range 6 to 62). Five patients have discontinued protocol therapy, all due to PD. No DLT’s have been observed. Related AE’s include grade 1: myalgia (1), anorexia (1), fatigue (2), headache (1), diarrhea (1), vomiting (1) and grade 2: fatigue (1). Preliminary PK analyses in the first 2 cohorts is shown in table below. Conclusions: ME-143 appears to be well tolerated when administered IV. Preliminary PK data suggest that drug levels achieve target concentration extrapolated from pre-clinical studies (AUC0-t ~10mg*hr/mL) and exceed levels obtained with IV PXD in the phase II study (AUC0-t ~2mg*hr/mL) . Updated clinical data from all planned dose cohorts, including the final pharmacokinetic analysis and planned phase II dose, will be presented. [Table: see text]