Abstract
Traditional pyrimidine antimetabolic chemotherapy agents like 5-FU and capecitabine face challenges such as resistance, toxicity, and variability in patient response, highlighting the need for new therapeutic strategies to improve patient outcomes. CLX-155A is a novel oral prodrug that combines 5-fluorouracil (5-FU) and valproic acid (VPA), aiming to enhance chemotherapy efficacy through synergistic mechanisms. This preclinical study addressed research questions relative to CLX-155A's preclinical activity, single-dose pharmacokinetic (PK) profile, and relative effects compared with capecitabine in FoxN1 athymic nude mouse models of human colorectal cancer (CRC).
This study assessed the anticancer efficacy of CLX-155A in a colorectal cancer xenograft mouse model utilizing seven groups (n=10/group) of FoxN1 athymic nude female mice. Investigators inoculated the FoxN1 athymic nude female mice with cancer cells and subsequently treated them with varying doses of CLX-155A, involving twice-daily (150 and 500 mg/kg twice daily) and once-daily (300 and 1000 mg/kg/day) schedules. The capecitabine group was a positive control, dosed at 1000 mg/kg/day (500 mg/kg/twice daily or 1000 mg/kg/day). They monitored tumor growth as the primary endpoint and evaluated the pharmacokinetic profile of 5-FU and its precursors (5’-DFCR, 5’-DFCR), along with that of VPA.
CLX-155A demonstrated a significant dose-dependent tumor growth (p<0.05) inhibition versus vehicle and was comparable to capecitabine. The evaluation of its single-dose pharmacokinetic profile reflected defined peaks for 5-FU and its precursors (5’-DFCR, 5’-DFCR), higher area under the curve (AUC) versus capecitabine, sustained release characteristics, and defined peaks and AUCs for valproic acid.
Overall, CLX-155A exhibits promising preclinical efficacy in a nude xenograft mouse model of colorectal cancer. Its dual-action mechanism and improved pharmacokinetic profile suggest potential advantages over existing therapies. Further studies are warranted to explore its clinical potential and optimize dosing strategies.