Use of paclitaxel carried in lipid core nanoparticles in patients with late-stage solid cancers with bone metastases: Lack of toxicity and therapeutic benefits.

Patients with heavily pretreated, late-stage cancer and bone metastasis are usually poor candidates for further chemotherapy. Previously, we showed that association to lipid nanoparticles (LDE) drastically decreases the toxicity of anti-cancer drugs. Here, we tested the hypothesis that paclitaxel (PTX) carried in LDE could benefit end-of-life patients with painful bone metastases that had been previously treated with conventional PTX. Methods: Eighteen consecutive patients with late-stage cancer, 8 with breast, 5 with prostate and 5 with lung carcinoma, aged 59±9 years, were included in this study. All were receiving opioid medication. LDE-PTX was administered at 175 mg/m 2 every 3 weeks until disease progression. Clinical imaging examinations and serum biochemistry determinations were performed to monitor disease progression. Intensity of bone pain, use of opioid medications and occurrence of pathological bone fractures were also evaluated. Results: In total, 104 chemotherapy cycles were performed and none of the patients showed clinical and laboratorial toxicities or pathological bone fractures. In all patients, pain was reduced so as to allow substitution of non-opioid for opioid medication. Median progression-free survival (PFS) was four months (95% CI 2.4-5.5), but in five patients PFS was longer than 6 months. Conclusions: Absence of observable clinical and laboratorial toxicities from LDE-PTX treatment, improvement of bone pain and the possible effect on PFS in some patients, despite previous use of conventional PTX, suggest that LDEPTX merits further clinical investigation .

Phase II study of paclitaxel associated with lipid core nanoparticles (LDE) as third-line treatment of patients with epithelial ovarian carcinoma.

Ovarian cancer is often diagnosed at advanced stages, when poorly responsive to standard treatment. First-line treatment consists in schemes including cytoreductive surgery followed by adjuvant chemotherapy schemes with platinum and taxane derivatives. Second-line regimens are based on gemcitabine and liposomal doxorubicin. Third line is often not worthwhile because of the high toxicity with poor response to treatment. Previously, we showed that paclitaxel (PTX) carried in non-protein lipid core nanoparticles (LDE) resembling the chemical structure of LDL has remarkably reduced toxicity. Here, the hypothesis was tested whether PTX-LDE could safely benefit patients in third-line treatment setting. Fourteen women unresponsive to second-line chemotherapy for ovarian cancer, aged 61 ± 10 years, clinical stage IV and TqNqM1, were included. PTX-LDE was administered at 175 mg/m2, 3/3 week dose. Patients were submitted to clinical examinations before each chemotherapy cycle. Serum biochemistry and imaging examinations to monitor disease progression were performed. In total, 74 cycles of chemotherapy were done and, in all cycles, clinical or laboratorial toxicities were not observed. Median progression-free survival (PFS) was 3.0 months (95% CI 2.0-3.9). In four patients, PFS was >6 months and in 2 > 1 year. The unpreceded, striking absence of toxicity and consistently long PFS, compared to previous results, indicate that at least 4 among 14 patients had tumor arrest by the treatment and clear benefit of PTX-LDE at third-line setting. The absence of observable toxicity allows dose escalating to improve response to treatment, as perspective to be tested in the ensuing studies.

Clinical experience with drug delivery systems as tools to decrease the toxicity of anticancer chemotherapeutic agents.

INTRODUCTION: The toxicity of chemotherapeutic agents, resulting from their low pharmacological index, introduces considerable discomfort and risk to cancer patients. Among several strategies to reduce the toxicity of chemotherapeutic agents, targeted drug delivery is the most promising one. Areas covered: Liposomes, micelles, albumin-based, polymeric, dendritic and lipid core nanoparticles have been used as carriers to concentrate anticancer drugs in neoplastic tissues, and clinical studies of those preparations are reviewed. In most clinical studies, drug delivery systems reduced drug toxicity. Lipid core nanoparticles (LDE) that bind to cell lipoprotein receptors have the ability to concentrate in neoplastic tissues and were the first artificial non-liposomal system shown in in vivo studies to possess targeting properties. The toxicity reduction achieved by LDE as vehicle of carmustine, etoposide and paclitaxel was singularly strong. Expert opinion: The reduced toxicity offered by drug delivery systems has expanded treatment population that may benefit from chemotherapy including feeble, overtreated and elderly patients that would otherwise be offered palliative therapy. Drug delivery systems may either prolong the duration of treatments or allow increases in drug dose.

Modification of composition of a nanoemulsion with different cholesteryl ester molecular species: effects on stability, peroxidation, and cell uptake.

PURPOSE: Use of lipid nanoemulsions as carriers of drugs for therapeutic or diagnostic purposes has been increasingly studied. Here, it was tested whether modifications of core particle constitution could affect the characteristics and biologic properties of lipid nanoemulsions. METHODS: Three nanoemulsions were prepared using cholesteryl oleate, cholesteryl stearate, or cholesteryl linoleate as main core constituents. Particle size, stability, pH, peroxidation of the nanoemulsions, and cell survival and uptake by different cell lines were evaluated. RESULTS: It was shown that cholesteryl stearate nanoemulsions had the greatest particle size and all three nanoemulsions were stable during the 237-day observation period. The pH of the three nanoemulsion preparations tended to decrease over time, but the decrease in pH of cholesteryl stearate was smaller than that of cholesteryl oleate and cholesteryl linoleate. Lipoperoxidation was greater in cholesteryl linoleate than in cholesteryl oleate and cholesteryl stearate. After four hours' incubation of human umbilical vein endothelial cells (HUVEC) with nanoemulsions, peroxidation was minimal in the presence of cholesteryl oleate and more pronounced with cholesteryl linoleate and cholesteryl stearate. In contrast, macrophage incubates showed the highest peroxidation rates with cholesteryl oleate. Cholesteryl linoleate induced the highest cell peroxidation rates, except in macrophages. Uptake of cholesteryl oleate nanoemulsion by HUVEC and fibroblasts was greater than that of cholesteryl linoleate and cholesteryl stearate. Uptake of the three nanoemulsions by monocytes was equal. Uptake of cholesteryl oleate and cholesteryl linoleate by macrophages was negligible, but macrophage uptake of cholesteryl stearate was higher. In H292 tumor cells, cholesteryl oleate showed the highest uptakes. HUVEC showed higher survival rates when incubated with cholesteryl stearate and smaller survival with cholesteryl linoleate. H292 survival was greater with cholesteryl stearate. CONCLUSION: Although all three nanoemulsion types were stable for a long period, considerable differences were observed in size, oxidation status, and cell survival and nanoemulsion uptake in all tested cell lines. Those differences may be helpful in protocol planning and interpretation of data from experiments with lipid nanoemulsions.

Modification of composition of a nanoemulsion with different cholesteryl ester molecular species Effects on stability, peroxidation, and cell uptake

Use of lipid nanoemulsions as carriers of drugs for therapeutic or diagnostic purposes has been increasingly studied. Here, it was tested whether modifications of core particle constitution could affect the characteristics and biologic properties of lipid nanoemulsions. Three nanoemulsions were prepared using cholesteryl oleate, cholesteryl stearate, orcholesteryl linoleate as main core constituents. Particle size, stability, pH, peroxidation of the nanoemulsions, and cell survival and uptake by different cell lines were evaluated.It was shown that cholesteryl stearate nanoemulsions had the greatest particlesize and all three nanoemulsions were stable during the 237-day observation period...