plitidepsin and Colorectal-Neoplasms

This phase I trial evaluated the toxicity profile and maximum tolerated dose of the combination between the marine derived cyclodepsipeptide plitidepsin and bevacizumab in advanced cancer patients. Thirteen patients were enrolled and treated with plitidepsin at three dose levels (2.8 mg/m, n=3; 3.8 mg/m, n=4; and 4.8 mg/m, n=6) with a fixed dose of bevacizumab (10 mg/kg). Both agents were administered intravenously at D1 and D15 of a 28-day cycle. All 13 patients were evaluable for safety and toxicity. Dose-limiting toxicities occurred in two out of six patients treated at the maximum dose tested (plitidepsin 4.8 mg/m and bevacizumab 10 mg/kg) and consisted of grade 3 fatigue, grade 3 myalgia, and two grade 2/3 alanine aminotransferase increases lasting for more than 7 days or leading to subsequent cycle delay greater than 2 weeks (n=1 each). The recommended dose for the combination of plitidepsin with bevacizumab was 3.8 mg/m for plitidepsin and 10 mg/kg for bevacizumab every 2 weeks. Most frequent treatment-related adverse events were nausea, vomiting, fatigue, epistaxis, and headache. Relevant hematological toxicity was minimal. Objective disease responses were not observed; however, stable disease (>3 months) was observed in four patients with colorectal cancer, renal cancer, and cervical cancer. Combining plitidepsin with bevacizumab combination is feasible. Stable disease was the best response obtained.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Bevacizumab; Carcinoma, Renal Cell; Colorectal Neoplasms; Depsipeptides; Dose-Response Relationship, Drug; Female; Humans; Kidney Neoplasms; Male; Middle Aged; Neoplasms; Peptides, Cyclic; Prospective Studies; Uterine Cervical Neoplasms

Encapsulating chemotherapy drugs in targeted nanodelivery systems is one of the most promising approaches to tackle cancer disease, avoiding side effects of common treatment. In the last decade, several nanocarriers with different nature have been tested, but polypeptide-based copolymers have attracted considerable attention for their biocompatibility, controlled and slow biodegradability as well as their low toxicity. In this work, we synthesized, characterized and evaluated poly(trimethylene carbonate)-bock-poly(L-glutamic acid) derived polymersomes, targeted to epidermal growth factor receptor (EGFR), loaded with plitidepsin and ultimately tested in HT29 and LS174T colorectal cancer cell lines for specificity and efficacy. Furthermore, morphology, physico-chemical properties and plitidepsin loading were carefully investigated. A thorough in vitro cytotoxicity analysis of the unloaded polymersomes was carried out for biocompatibility check, studying viability, cell membrane asymmetry and reactive oxygen species levels. Those cytotoxicity assays showed good biocompatibility for plitidepsin-unloaded polymersomes. Cellular uptake and cytotoxic effect of EGFR targeted and plitidepsin loaded polymersome indicated that colorectal cancer cell lines were.more sensitive to anti-EGFR-drug-loaded than untargeted drug-loaded polymersomes. Also, in both cell lines, the use of untargeted polymersomes greatly reduced plitidepsin cytotoxicity as well as the cellular uptake, indicating that the use of this targeted nanocarrier is a promising approach to tackle colorectal cancer disease and avoid the undesired effects of the usual treatment. Furthermore, in vivo assays support the in vitro conclusions that EGFR targeted polymersomes could be a good drug delivery system. This work provides a proof of concept for the use of encapsulated targeted drugs as future therapeutic treatments for cancer.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Survival; Colorectal Neoplasms; Depsipeptides; Dioxanes; Drug Carriers; ErbB Receptors; Female; HT29 Cells; Humans; Mice; Mice, Nude; Necrosis; Peptides, Cyclic; Polyglutamic Acid; Polymers; Xenograft Model Antitumor Assays