NEW YORKLiposomal doxorubicin (Doxil) may be essentially equivalent to
topotecan (Hycamtin) as second-line therapy for ovarian cancer, but the
combination of the two may have more promise than either agent alone, according
to preliminary results of a phase I study.
Franco Muggia, MD, director of medical oncology, New York University (NYU)
School of Medicine, reported results suggesting that some patients have
"very long responses" on liposomal doxorubicin plus topotecan.
"From our preliminary results, one might expect that the response rates
with the combination will exceed those of either drug alone," he said at
the Chemotherapy Foundation Symposium XIX (abstract 31).
Liposomal doxorubicin alone has been characterized in a large, randomized
trial as a suitable treatment option in recurrent epithelial ovarian carcinoma.
This is because of its favorable safety profile, convenient dosing, and
efficacy comparable to topotecan, which has been studied extensively in
Similar Response Rates
In this phase III study of 474 patients with recurrent epithelial ovarian
carcinoma, the two agents showed similar overall response rates and median
overall survival times. Liposomal doxorubicin was superior to topotecan in
overall survival time (median, 108 weeks vs 71.1 weeks, P = .008), while there
was a survival trend in favor of topotecan for the platinum-refractory patients
(Gordon AN et al: J Clin Oncol 19:3312-3322, 2001).
Several points about the study are interesting in light of ongoing
investigations looking at dual-topoisomerase inhibition in the second-line
Dr. Muggia noted that both topotecan and liposomal doxorubicin have response
rates over 25% in platinum-sensitive patients. The curves for progression-free
survival and overall survival for the two agents vary, despite similar medians.
This fact suggests that continued therapy with liposomal doxorubicin might
improve the two extremes of the survival curves, he said.