Data presented at the 18th Annual San Antonio Breast Cancer Symposium in Boulder, Colorado, shows that moderate-dose DaunoXome, NeXstar Pharmaceuticals' liposomal formulation of daunorubicin(Drug information on daunorubicin), is well-tolerated and has promising efficacy in treating advanced breast cancer. Moreover, the limited toxicity observed in this trial, particularly the absence of cardiotoxicity, suggests that DaunoXome may be useful in ameliorating the side effects that accompany high-dose anthracycline-based chemotherapy for metastatic breast cancer. The data, generated in a phase II study funded by NeXstar, were presented by P.S. Hupperets, MD, of the Akademisch Ziekenhuis, in Maastricht, The Netherlands.
In the study, 11 women with previously untreated, newly diagnosed metastatic breast cancer received DaunoXome at a dose of 100 mg/m² every 3 weeks for as long as 24 weeks. Even at this moderate dose, three patients (27%) developed a partial response, seven (63%) had stable disease, and one patient (10%) experienced no therapeutic benefit. Toxicity was minimal; no patient lost hair, and only two patients reported mild nausea. Six patients showed evidence of bone marrow suppression, which did not limit treatment and which recovered without supportive therapy. No patient exhibited signs of cardiotoxicity.
"These data demonstrate that moderate-dose DaunoXome therapy produces the same kind of response rates as conventional single-agent doxorubicin(Drug information on doxorubicin) therapy, but a much improved side-effects profile," said Michael E. Ross, NeXstar's vice president for medical and regulatory affairs. "We believe that these results bode well not only for the expanded trials we're conducting in breast cancer, but for the other solid tumor indications in which DaunoXome is being tested. We also believe that the absence of cardiotoxicity suggests that DaunoXome may play an important role in replacing conventional anthracyclines in high-dose, multiple-agent chemotherapy regimens." Such studies are currently in progress.
DaunoXome has already been approved in the United Kingdom and Sweden as a primary therapy for advanced Kaposi's sarcoma in HIV-positive patients and is awaiting final approval in the United States for the same indication. In addition to the phase II study in breast cancer, NeXstar is conducting phase II trials with DaunoXome in small-cell lung cancer, non-small-cell lung cancer, hepatocellular cancer, adult and childhood leukemia, brain tumors, bladder cancer, and lymphoma.