DrugLib.com — Drug Information Portal

Rx drug information, pharmaceutical research, clinical trials, news, and more

Daunoxome (Daunorubicin Citrate) - Description and Clinical Pharmacology



DaunoXome (daunorubicin citrate liposome injection) is a sterile, pyrogen-free, preservative-free product in a single use vial for intravenous infusion.

DaunoXome contains an aqueous solution of the citrate salt of daunorubicin encapsulated within lipid vesicles (liposomes) composed of a lipid bilayer of distearoylphosphatidylcholine and cholesterol (2:1 molar ratio), with a mean diameter of about 45 nm. The lipid to drug weight ratio is 18.7:1 (total lipid:daunorubicin base), equivalent to a 10:5:1 molar ratio of distearoylphosphatidylcholine:cholesterol:daunorubicin. Daunorubicin is an anthracycline antibiotic with antineoplastic activity, originally obtained from Streptomyces peucetius. Daunorubicin has a 4-ring anthracycline moiety linked by a glycosidic bond to daunosamine, an amino sugar. Daunorubicin may also be isolated from Streptomyces coeruleorubidus and has the following chemical name: (8S-cis)-8-acetyl-10-[(3-amino-2,3,6-trideoxy-α-L-lyxo-hexopyranosyl)oxy]-7,8,9,10-tetrahydro-6,8,11-trihydroxy-1-­methoxy-5,12-naphthacenedione hydrochloride.

Daunorubicin citrate has the following chemical structure:

DSPC (distearoylphosphatidylcholine) has the following chemical structure:

The following represents the idealized, spherical morphology of a liposome:

Note: Liposomal encapsulation can substantially affect a drug's functional properties relative to those of the unencapsulated drug.

In addition, different liposomal drug products may vary from one another in the chemical composition and physical form of the liposomes. Such differences can substantially affect the functional properties of liposomal drug products.

Each vial contains daunorubicin citrate equivalent to 50 mg of daunorubicin base, encapsulated in liposomes consisting of 704 mg distearoylphosphatidylcholine and 168 mg cholesterol. The liposomes encapsulating daunorubicin are dispersed in an aqueous medium containing 2,125 mg sucrose, 94 mg glycine, and 7 mg calcium chloride dihydrate in a total volume of 25 mL/vial. The pH of the dispersion is between 4.9 and 6.0. The liposome dispersion should appear red and translucent.


Mechanism of Action

DaunoXome is a liposomal preparation of daunorubicin formulated to maximize the selectivity of daunorubicin for solid tumors in situ. While in the circulation, the DaunoXome formulation helps to protect the entrapped daunorubicin from chemical and enzymatic degradation, minimizes protein binding, and generally decreases uptake by normal (non-reticuloendothelial system) tissues. The specific mechanism by which DaunoXome is able to deliver daunorubicin to solid tumors in situ is not known. However, it is believed to be a function of increased permeability of the tumor neovasculature to some particles in the size range of DaunoXome. In animal studies, daunorubicin has been shown to accumulate in tumors to a greater extent when administered as DaunoXome than when administered as daunorubicin. Once within the tumor environment, daunorubicin is released over time enabling it to exert its antineoplastic activity.


Following intravenous injection of DaunoXome, plasma clearance of daunorubicin shows monoexponential decline. The pharmacokinetic parameter values for total daunorubicin following a single 40 mg/m2 dose of DaunoXome administered over a 30 – 60 minute period to patients with AIDS-related Kaposi's sarcoma and following a single rapid intravenous, 80 mg/m2 dose of conventional daunorubicin to patients with disseminated solid malignancies are shown in Table I.

Parameter (units) aDaunoXome bConventional Daunorubicin
a N=30; b N=4; c Calculated
Plasma Clearance (mL/min) 17.3 ± 6.1 c236 ± 181
Volume of Distribution (L) 6.4 ± 1.5 1006 ± 622
Distribution Half-Life (h) 4.41 ± 2.33 0.77 ± 0.3
Elimination Half-Life (h) ——— 55.4 ± 13.7

The plasma pharmacokinetics of DaunoXome differ significantly from the results reported for conventional daunorubicin hydrochloride. DaunoXome has a small steady-state volume of distribution of 6.4 L, (probably because it is confined to vascular fluid volume), and clearance of 17 mL/min. These differences in the volume of distribution and clearance result in a higher daunorubicin exposure (in terms of plasma AUC) from DaunoXome than with conventional daunorubicin hydrochloride. The apparent elimination half-life of DaunoXome (daunorubicin citrate liposome injection) is 4.4 hours, far shorter than that of daunorubicin, and probably represents a distribution half-life. Although preclinical biodistribution data in animals suggest that DaunoXome crosses the normal blood-brain barrier, it is unknown whether DaunoXome crosses the blood-brain barrier in humans.

Metabolism: Daunorubicinol, the major active metabolite of daunorubicin, was detected at low levels in the plasma following intravenous administration of DaunoXome.

No formal assessments of pharmacokinetic drug–drug interactions between DaunoXome and other agents have been conducted.

Special Populations: The pharmacokinetics of DaunoXome have not been evaluated in women, in different ethnic groups, or in subjects with renal and hepatic insufficiency.

Clinical Study

In an open-label, randomized, controlled clinical study conducted at 13 centers in the U.S.A. and Canada in advanced (25 or more mucocutaneous lesions; the development of 10 or more lesions in a one month period of time; symptomatic visceral involvement; or tumor-associated edema) HIV-related Kaposi's sarcoma, two treatment regimens were compared as first line cytotoxic therapy: DaunoXome 40 mg/m2and ABV (doxorubicin (Adriamycin®1) 10 mg/m2, bleomycin 15 U, and vincristine 1.0 mg). All drugs were administered intravenously every 2 weeks. Responses were assessed using the AIDS Clinical Trials Group Oncology Committee of the National Institute of Allergy and Infectious Diseases (ACTG) criteria (a response required at least one of any of the following for at least 28 days: a. ≥ 50% reduction in the number; b. ≥ 50% reduction in the sums of the products of the largest perpendicular diameters of bidimensionally measurable marker lesions; or c. complete flattening of ≥ 50% of all previously raised lesions). Table II summarizes the efficacy results.

1. Adriamycin is a registered trademark of Pharmacia & Upjohn Co., Kalamazoo, MI.

* The 95% confidence interval for difference in the response rates (ABV – DaunoXome) was (-5%, 18%).
** The hazard ratio (ABV/DaunoXome) for duration of response was 0.80, and the 95% confidence intervals were (0.44, 1.46).
*** The hazard ratio (ABV/DaunoXome) for time to progression was 0.78, and the 95% confidence intervals were (0.57, 1.07).
**** The hazard ratio for mortality (ABV/DaunoXome) was 1.29, and 95% confidence intervals were (0.92, 1.79).
Response Rate 23%* 30%
Duration of Response, Median 110 days** 113 days
Time to Progression, Median 92 days *** 105 days
Survival 342 days **** 291 days

Twenty of the 33 ABV responders responded to therapy by criteria more stringent than flattening of lesions (i.e., shrinkage of lesions and/or reduction in the number of lesions). Eleven of the 27 DaunoXome responders responded to therapy by criteria other than flattening of lesions. Photographic evidence of tumor response to DaunoXome and ABV was comparable across all anatomic sites (e.g., face, oral cavity, trunk, legs, and feet).

-- advertisement -- The American Red Cross
Home | About Us | Contact Us | Site usage policy | Privacy policy

All Rights reserved - Copyright DrugLib.com, 2006-2017