Abstract 1777: Antitumor effect of PM01183 in a human pancreatic adenocarcinoma orthotopic model

Abstract

Abstract Background: Pancreatic ductal adenocarcinoma is the fourth cause of death in the Western world and, despite the advances in cancer therapies, limited therapeutic benefit (palliating symptoms, better quality of life) may be offered to patients: the overall 5-year survival rate remains < 5%. PM01183 is a new synthetic tetrahydroisoquinoline alkaloid that binds to selected DNA sequences and promotes apoptosis by inducing double-strand breaks at nanomolar concentrations. Confirmed antitumor clinical activity was observed at the recommended dose level of PM01183 in the first-in-human Phase I study in patients with advanced/refractory solid tumors. Currently, PM01183 clinical development includes Phase II single agent trials (pancreas, breast and platinum-resistant/refractory ovarian) as well as Phase I trials in combination (with doxorubicin and gemcitabine) and in advanced acute leukemia. The in vivo antitumor activity of PM01183 was investigated in the human NP9 pancreatic orthotopic model Material and Methods: Athymic nude female mice were orthotopically implanted with luciferase-expressing NP9Luc tumors. Fifteen days after implantation, tumor bearing mice were randomly allocated (N=12 /group) into either PM01183 (at 0.18 mg/kg), gemcitabine (at 180 mg/kg) or control (placebo) groups. Treatments were initiated (Day 0) and administered for 3 consecutive weeks (q7dx3; days 0, 7, 14). Response to treatment was assessed on Day 7 (short-term) by bioluminescence imaging (BLI), and by survival evaluation (long-term): mice were sacrificed when their tumor diameters reached ca. 2 cm or when they became moribund. Statistical differences between groups were determined using two-tailed Mann-Whitney U test and by analysis of the Kaplan-Meier curve. Results: Results showed that PM01183 (q7dx3 at 0.18 mg/kg) induced statistically significant tumor reduction compared to placebo-treated animals by BLI analysis (P= 0.006) on Day 7. Reductions in tumor size were associated to changes in survival median times: PM01183 treatment significantly increased the survival time compared to either gemcitabine- (P= 0.003) or placebo-treated (P= 0.0001) animals. Conclusion: PM01183 demonstrated in vivo antitumor activity in a human pancreatic orthotopic model (NP9), as reflected by metabolic, size-related and survival rate. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1777. doi:1538-7445.AM2012-1777