284 Background: Wild toad venom has been used for over 1,000 years as a traditional Chinese medicine; H, the extract of dried toad skin glands, is a potent cardiac glycoside without significant toxicity. H has demonstrated preliminary evidence of antitumor activity in phase I clinical trial evaluation (Cancer 2009, 115:5309-18). Methods: We conducted a randomized, single-blind, phase II clinical trial of G + H versus G + placebo in patients with LAPC or MPC. Plasma bufalin levels were performed in H-treated subjects. 80 evaluable subjects accrued from October 2007 to May 2010 and were treated with G 1,000mg/m2 (iv on days 1, 8, 15, q 28d) plus either H (20 mL/m2 iv daily for 21 days followed by 7 days off, q 28d) or placebo. Demographic data is demonstrated in the table below. Results: Grade 3/4 adverse events, objective radiographic response rates (ORR), time to progression (TTP), quality of life (QOL), and overall survival (OS) were similar in the two groups (Table). There was not a statistically significant difference in the average plasma bufalin levels in patients with a radiographic partial response (PR) or stable disease versus those with progressive disease (PD) (0.098 ± 0.093 ng/mL vs. 0.071 ± 0.048 ng/mL, p=0.679). Conclusions: H when added to G was well tolerated but did not improve OS, TTP, QOL, or ORR. Further investigation of a more potent oral formulation of H is planned. H provided by Shenzhen 999 Traditional Chinese Medicine & Development Co., Ltd. Supported by NIH U19CA121503-01. [Table: see text] No significant financial relationships to disclose.