Comparison of Efficacy and Peripheral Neuropathy of Solvent-based Paclitaxel with Paclitaxel Poliglumex and NK105: A Systematic Review and Metaanalysis

Background and Introduction: Peripheral neuropathy is one of the most common dose-limiting side effects of solvent-based paclitaxel. Paclitaxel poliglumex (PPX) and NK105 were developed to overcome the paclitaxel induced peripheral neuropathy. However, the incidence of peripheral neuropathy induced by PPX and NK105 was reported higher than solvent-based paclitaxel, but evidence remains inconsistent.

METHODS

The article was reported in accordance with PRISMA Guidelines (Registration number: CRD42021245313). We conducted a meta-analysis to compare the incidence and severity of peripheral neuropathy between solvent-based paclitaxel, PPX and NK105 mono-chemotherapy.

RESULTS

Results revealed that no significant difference exists between the incidence of all grade peripheral neuropathy among the solvent-based paclitaxel, PPX and NK105 treated groups. While, the incidence of high grade peripheral neuropathy induced by NK105 was lower than two other groups. Moreover, the overall survival was not improved in PPX compared with other groups. However, NK105 demonstrated significant longer overall survival in patients with cancer.

CONCLUSION

Current evidence suggests more attention should be paid to the paclitaxel poliglumex re-formulation.

Polypeptide-based drug delivery systems for programmed release

Recent years have seen increasing interests in the use of ring-opening polymerization of α-amino acid N-carboxyanhydrides (NCAs) to prepare synthetic polypeptides, a class of biocompatible and versatile materials, for various biomedical applications. Because of their rich side-chain functionalities, diverse hydrophilicity/hydrophobicity profiles, and the capability of forming stable secondary structures, polypeptides can assemble into a variety of well-organized nano-structures that have unique advantages in drug delivery and controlled release. Herein, we review the design and use of polypeptide-based drug delivery system derived from NCA chemistry, and discuss the future perspectives of this exciting and important biomaterial area that may potentially change the landscape of next-generation therapeutics and diagnosis. Given the high significance of precise control over release for polypeptide-based systems, we specifically focus on the versatile designs of drug delivery systems capable of programmed release, through the changes in the chemical and physical properties controlled by the built-in molecular structures of polypeptides.

Cathepsin-sensitive nanoscale drug delivery systems for cancer therapy and other diseases

Cathepsins are an important category of enzymes that have attracted great attention for the delivery of drugs to improve the therapeutic outcome of a broad range of nanoscale drug delivery systems. These proteases can be utilized for instance through actuation of polymer-drug conjugates (e.g., triggering the drug release) to bypass limitations of many drug candidates. A substantial amount of work has been witnessed in the design and the evaluation of Cathepsin-sensitive drug delivery systems, especially based on the tetra-peptide sequence (Gly-Phe-Leu-Gly, GFLG) which has been extensively used as a spacer that can be cleaved in the presence of Cathepsin B. This Review Article will give an in-depth overview of the design and the biological evaluation of Cathepsin-sensitive drug delivery systems and their application in different pathologies including cancer before discussing Cathepsin B-cleavable prodrugs under clinical trials.

Phase I trial of poly-L-glutamate camptothecin (CT-2106) administered weekly in patients with advanced solid malignancies

PURPOSE

CT-2106 is a 20(S)-camptothecin poly-L-glutamate conjugate. This linkage stabilizes the active lactone form of camptothecin and enhances aqueous solubility. In addition, poly-L-glutamate is postulated to increase tumor delivery of the active compound through enhanced permeability and retention effect in tumor. We studied a weekly schedule of CT-2106 in patients with refractory solid tumor malignancies.

EXPERIMENTAL DESIGN

CT-2106 was infused (10 min i.v. infusion) on days 1, 8, and 15 of each 28-day cycle. Plasma and urine were analyzed for total and unconjugated camptothecin by high-performance liquid chromatography equipped with a fluorescence detector. Toxicity and response assessments were done with Common Toxicity Criteria for Adverse Events version 3 and Response Evaluation Criteria in Solid Tumors, respectively.

RESULTS

Twenty-six patients were enrolled. Median age was 58 years (range, 36-83) and median number of doses was 6 (range, 1-9). The most frequent tumor type (50%) was melanoma. Dose limiting toxicities were thrombocytopenia and fatigue. A weekly dose of 25 mg/m2 given every 3 of 4 weeks was the maximum tolerated dose. The majority of grade 3 and 4 toxicities were hematologic. The pharmacokinetic profile of conjugated and unconjugated camptothecin showed a polyexponential decline with similar terminal half life (t1/2 range was 44-63 and 31-48 h for conjugated and unconjugated, respectively). Pharmacokinetics of conjugated and unconjugated camptothecin were dose and time independent in the tested dose range. Urinary excretion of conjugated and unconjugated camptothecin accounted for about 30% and 4% of the administered dose, respectively.

CONCLUSIONS

CT-2106 has a more manageable toxicity profile compared with unconjugated camptothecin. The maximum tolerated dose is 25 mg/m2 weekly given 3 of 4 weeks. This compound results in prolonged release of unconjugated camptothecin.

Polymer conjugates: nanosized medicines for treating cancer

Interdisciplinary research at the interface of polymer chemistry and the biomedical sciences has produced the first polymer-based nanomedicines for the diagnosis and treatment of cancer. These water-soluble hybrid constructs, designed for intravenous administration, fall into two main categories: polymer-protein conjugates or polymer-drug conjugates. Polymer conjugation to proteins reduces immunogenicity, prolongs plasma half-life and enhances protein stability. Polymer-drug conjugation promotes tumor targeting through the enhanced permeability and retention (EPR) effect and, at the cellular level following endocytic capture, allows lysosomotropic drug delivery. The successful clinical application of polymer-protein conjugates (PEGylated enzymes and cytokines) and promising results arising from clinical trials with polymer-bound chemotherapy (e.g. doxorubicin, paclitaxel, camptothecins) has provided a firm foundation for more sophisticated second-generation constructs that deliver the newly emerging target-directed anticancer agents (e.g. modulators of the cell cycle, signal transduction inhibitors and antiangiogenic drugs) in addition to polymer-drug combinations (e.g. endocrine- and chemo-therapy).