Lack of benefit of maintenance paclitaxel in first-line chemotherapy in metastatic breast cancer

Purpose This randomized study compared maintenance paclitaxel with control in metastatic breast cancer patients not experiencing progression after first-line anthracycline/paclitaxel combination chemotherapy. Methods Between April 1998 and October 2003, 459 metastatic breast cancer patients received first-line combination chemotherapy with epirubicin or doxorubicin plus paclitaxel. Of these, 255 who had a response or stable disease were then randomly assigned onto the Maintenance Paclitaxel 1 (MANTA1) study, comparing eight courses of maintenance paclitaxel versus control (ie, no additional chemotherapy administration). The primary end point was progression-free survival. Results The study was prematurely concluded after a futility analysis, which was performed on 215 of the 238 patients randomly assigned within December 2002. Of these, 109 patients were assigned to maintenance paclitaxel and 106 were assigned to stopping chemotherapy. No significant difference in median progression-free survival was observed (8.0 months for maintenance paclitaxel and 9.0 months for control). There was no significant difference in median survival time (28.0 v 29.0 months). When the Bayesian method for monitoring clinical trials was applied to these data, even under an enthusiastic prior distribution, in the posterior distribution there was only an 8.6% chance of observing a 3-month improvement in median progression-free survival in the group receiving maintenance paclitaxel. After these results study accrual was closed. Conclusion Compared with control, the administration of additional courses of paclitaxel in patients who achieve disease control after six to eight courses of first-line anthracycline plus paclitaxel combination chemotherapy does not improve progression-free survival.