Liposomal daunorubicin (DaunoXome) for treatment of poor-risk acute leukemia.

Toxicity limits the use of anthracyclines in elderly sick patients and in heavily pretreated patients. Since the liposomal preparation of daunorubicin (DNR) (DaunoXome, or DNX) is expected to be less toxic than conventional DNR, we tested DNX combined with high-dose arabinosyl cytosine (HDAC) in 42 adult poor-risk acute leukemia patients. Thirty-one patients had acute non-lymphocytic leukemia (ANLL). Of these, 12 patients were newly diagnosed but were not eligible for standard induction treatment, 13 were in first relapse, and 6 were in second or subsequent relapse. Eleven patients had acute lymphocytic leukemia (ALL), in first (eight cases) or second (three cases) relapse. DNX was given i.v. in three doses of 80 or 100 mg/m(2) each (days 1-3) by a 60-min infusion in glucose 5%, followed by a 4-h infusion of HDAC 2 g/m(2) (days 1-5). Among 31 ANLL patients there were 16 (51%) complete remissions (CR), 5 deaths during induction, and 10 failures. Among 11 ALL patients there were 10 CRs and 1 failure. The response rate was not affected by the overexpression of MDR-related proteins (PgP, MRP-1, and LRP). Non-hemopoietic toxicity was negligible, with no intestinal toxicity and only one case of gram-negative bacteremia. We conclude that DNX, in combination with HDAC, is an effective treatment for poor-risk adult AL. Because of the low non-hematologic toxicity, it can be used to reinduce remission in poor-risk patients who are candidates for allogeneic bone marrow transplantation. The high CR rate observed in ALL requires confirmation.

Distribution of daunorubicin and daunorubicinol in human glioma tumors after administration of liposomal daunorubicin.

DaunoXome is a liposome formulation containing daunorubicin (DM). Encapsulation of the drug in liposomes presents the advantage of low-level systemic exposure and better drug penetration into the tumor. We studied the distribution of DM and its 13-dihydro metabolite, daunorubicinol (DMol), in surgical biopsies from different parts of glioblastomas. The study was performed in eight patients with recurrent glioblastoma, all of whom had previously undergone surgery and been treated with radiotherapy and chemotherapy, who received 50 mg of DaunoXome as a 1-h infusion. Surgery was performed at 24 and 48 h after the infusion in seven cases and one case, respectively. Biopsies were divided into three parts: the central area of the tumor, peripheral tumor tissue, and brain-adjacent tumor (BAT) tissue. A complete plasma pharmacokinetics study was conducted in seven cases, with samples being taken for up to 48 h after the end of the infusion. DM and DMol were determined in plasma and tissue by high-performance liquid chromatography with fluorescence detection after solvent extraction. At 24 h, concentrations of DM and DMol in the central part of the tumor ranged between < 0.005 and 0.80 microg/g and between 0.005 and 1.58 microg/g, respectively. Concentrations were similar in the peripheral tumor and in BAT tissue. From the data obtained on the patient who underwent surgery at 48 h it appears that DM and DMol remain in tumor tissue for a long time, the concentrations being 0.4 and 2.8 microg/g, respectively. DaunoXome was rapidly cleared from the body, with the plasma levels of DM and DMol determined at 48 h lying in the range of < 5-50 and < 5-20 ng/ml, respectively. The mean (+/-SD) half-life and plasmatic clearance of DM were 4.8+/-1.0 h and 0.2+/-0.06 l h(-1) m(-2). In conclusion, DaunoXome achieved and maintained potentially cytotoxic levels of both DM and DMol in glioblastoma for a long time in association with low-level systemic exposure. Further studies are therefore warranted. Although only preliminary and obtained in previously treated patients, these data suggest that DaunoXome merits investigation in CNS tumors.