Association of paclitaxel to lipid nanoparticles in the treatment of bone metastasis in patients with solid tumors.

Abstract

e21631 Background: Bone metastasis occurs in more than 65-90% patients with hormone-dependent solid tumors, as breast and prostate cancer, with slow evolution, being not responsive to standard chemotherapeutic agents, which restricts treatment options. Previously, we have shown that lipid nanoparticles resembling LDL-cholesterol-like are uptake in malignant tissues and capable of delivery anti-cancer drugs, after intravenous injection. The delivery of drug drastically reduced toxicity. The objective of this study was to evaluate the clinical responses to treatment with paclitaxel associated to nanoparticles, laboratory toxicity and pain scale in patients with breast and prostate carcinoma, previously treated with conventional schemes chemotherapy and not eligible for subsequent treatment. Methods: We included six patients with prostate carcinoma, and ten patients with breast carcinoma (age 68 ± 4 and 55 ± 7 years, respectively). All patients had advanced clinical staging IV at diagnosis (TNM-UICC classification). Treatment consisted in the combination of paclitaxel to lipid nanoparticles (dose: 175 mg/m2 body surface), intravenous, every 21 days, without premedications. Biochemistry determinations were performed before onset and every three weeks during treatment. To assess pain, we used the Verbal Analogue Scale (from zero to 10) and the use of opioids in the treatment period. Results: Total of 64 cycles were performed without clinical or laboratory toxicity. At the beginning of treatment the pain score was 8 (range 6-9), after six weeks it reduced to a mean of 6 (range 4-8) and after 18 weeks reduced to 4 (range 2-8). Six patients required 180 mg/day of morphine, but after 12 weeks the dose was reduced to 60 mg/day. Six patients progressed after three cycles requiring use of potent analgesic. Conclusions: The notable absence of toxicity and significant improvement in pain indicate paclitaxel associated to lipid nanoparticles as a promising option in chemotherapy regimens.