ASCO--Topotecan (Hycamtin), an inhibitor of topoisomerase I, significantly
increased time to disease progression--23 weeks vs 14 weeks for
paclitaxel (Taxol)--when used as second-line therapy in women
with recurrent ovarian cancer, James Carmichael, MD, of the University
of Nottingham, said at an ASCO scientific session.
Topotecan was well tolerated by most patients, he said, but "myelosuppression
occurred in a high proportion of patients and was severe in a
number of them." He called the problem "predictable
and manageable with the use of growth factors or modest dose reductions."
The phase III multinational trial, sponsored by SmithKline Beecham,
randomized 235 patients who had received one prior platinum-containing
Many patients did not show a response to topotecan until they
had received three courses or more, he said, "so it is important
to continue treatment to achieve the maximum response rate."
Among the paclitaxel failures, 53 patients were crossed over to
topotecan, and five partial responses were seen. "I think
this is important that we are seeing responses both in platinum
and paclitaxel failures," Dr. Carmichael said.
The discussant, David S. Alberts, MD, of the University of Arizona,
called topo-tecan an important new agent, but pointed out that
in this study, it was compared to what may be an inferior paclitaxel
regimen, ie, 3-hour vs 24-hour infusion.