Evaluation Of Ff-10502-01, A New Pyrimidine Nucleoside Analogue, In Pancreatic (Panc) Patient-Derived Xenograft (Pdx) Models Compared To Gemcitabine And In Combination With Nab-Paclitaxel

Introduction FF-10502-01 is a synthetic pyrimidine nucleoside analogue structurally similar to gem with a substitution of sulfur for oxygen in the pentose sugar. In previous studies, FF-10502-01 demonstrated preclinical efficacy across multiple solid tumors, including PANC cancer. In this study, we investigated the anti-tumor effect of FF-10502-01 in PANC PDX models. Methods 10 PANC PDX tumors were sourced from primary (2) or metastatic sites (8). 7 demonstrated high resistance (HR) to gem, 1 intermediate, and 2 low. In the dose-finding study, 3 PDX models were studied in 9 grps of NOD-SCID mice (n=10/grp), treated with 240 or 480 mg/kg FF-10502-01, 3 or 6 mg/kg nab-pac or 240 mg/kg gem, alone and in combination for 28d, followed by 28d observation. The definitive study consisted of 7 PDX models. 6 grps (n=10/grp) were treated with 240 or 480 mg/kg FF-10502-01, 6 mg/kg nab-pac or 240 mg/kg gem, alone and/or in combination for 28d, followed by 28d observation. After subcutaneous transplantation, animals were left undisturbed for 7d. Animals were monitored weekly and tumor volume measured with calipers. Average tumor volume (mm 3 ) for each group at randomization into treatment grps ranged from 184.34 – 199.51 (SD ± 20.94 – 30.40). Statistical significance was determined using one-way ANOVA and Tukey’s test. Results At clinically relevant doses, FF-10502-01, alone and in combination with nab-pac demonstrated greater tumor growth suppression than vehicle-treated animals (p≤0.0001). In 7 models, FF-10502-01/nab-pac demonstrated higher tumor growth suppression than gem/nab-pac (p≤0.5, p≤0.01 or p≤0.001), irrespective of resistance to gem. In 3 models, there was no difference, but these models were highly responsive to gem/nab-pac, thus minimizing the effects of FF-10502-01/nab-pac. Despite statistical insignificance, FF-10502-01/nab-pac still demonstrated greater tumor growth inhibitory activity to gem/nab-pac. In HR gem models, FF-10502-01 was superior to gem (p≤0.0001, p≤0.001, p≤0.05) in 3 of 7, and FF-10502-01/nab-pac was superior to gem/nab-pac in 6 of 7 (p nab-pac (p≤0.0001, p≤0.0001, p≤0.01, p≤0.05). FF-10502-01/nab-pac also was more tolerable than gemcitabine/nab-pac, as demonstrated by less weight loss. Conclusions FF-10502-01 is a new pyrimidine nucleoside analogue with demonstrated preclinical efficacy in solid tumors, including PANC cancer. In PANC PDX models, FF-10502-01 alone and in combination with nab-pac demonstrated higher efficacy and better tolerability than gem alone or gem/nab-pac. FF-10502-01 is in Phase 1 clinical development. Citation Format: Takeaki Suzuki, Linda J. Paradiso, Jill Ricono, Jonathan Nakashima, Yoshihide Iwaki, Shinji Mima, Takayuki Yamada, Chihaya Kakinuma, Hiroyuki Iwamura, Shinichi Watanabe. Evaluation of FF-10502-01, a new pyrimidine nucleoside analogue, in pancreatic (PANC) patient-derived xenograft (PDX) models compared to gemcitabine and in combination with nab-paclitaxel [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5112. doi:10.1158/1538-7445.AM2017-5112