Efficacy, Tolerability and Safety of Intravenous D-VC With ATO in Patients With Advanced/Metastatic Colorectal Cancer

The goal of this exploratory phase I/II single-center clinical trial is to evaluate effectiveness, tolerability, and safety of Intravenous D-isoascorbic Acid (D-VC) With Arsenic Trioxide in Patients With Advanced/Metastatic Colorectal Cancer Who Have Exhausted Standard Therapy The main questions are to learn about effectiveness, tolerability, and safety of Intravenous D-isoascorbic Acid (D-VC) With Arsenic Trioxide. The study aims to: 1. Assess the tolerability and pharmacokinetics of D-isoascorbic acid (D-VC) with a single intravenous injection in the monotherapy regimen and in the sequential administration regimen with arsenic trioxide (ATO) in patients on standard therapy for advanced/metastatic malignancies (Phase I) 2. Evaluate the efficacy and safety of D-isoascorbic acid (D-VC) with repeated intravenous administration in the mode of sequential administration with arsenic trioxide (ATO) in patients who have exhausted standard therapy for advanced/metastatic colorectal cancer (Phase II) In phase I participants will receive single intravenous administration as monotherapy of D-isoascorbic acid (D-VC) with dose escalation (0.05, 0.1, 0.2 g/kg/day) and with arsenic trioxide (ATO). Patients who have satisfactorily tolerated the study drug in combination with arsenic trioxide (ATO) in a phase I study are transferred to a phase II clinical trial. To study the safety and efficacy of the study drug in phase II, D-VC after the administration of ATO will be implemented in 2 groups: Study group 1: ATO (at a dose of 0.15 mg / kg / day) after intravenous administration after 2 hours D-VC intravenously once a day at the maximum tolerated dose, determined at the end of phase I for at least 15 patients. Group 2 standard therapy: 15 patients. For the phase I researchers will compare laboratory tests (including clinical biochemistry and hematology), vital signs, clinical adverse events (diseases, symptoms and complaints) and other specific safety tests (for example, an e