ASCO--Topotecan (Hycamtin), an inhibitor of topoisomerase I, significantly increased time to disease progression--23 weeks vs 14 weeks for paclitaxel(Drug information on 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(Drug information on 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 regimen.
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.