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, 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 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,