CRPC patients who completed first-line docetaxel therapy without disease progression have been offered a docetaxel rechallenge, and the responders have undergone further rechallenges until the appearance of docetaxel resistance. We assessed their clinical outcomes and evaluated all the variables potentially capable of predicting the response to rechallenge by means of uni- and multivariate analysis.
Forty-six consecutive patients underwent 92 rechallenges. The overall biochemical response rate (prostate-specific antigen [PSA] reduction >50%) was 66%. Median overall survival was 32 months with a projected 2-year overall survival from the first docetaxel administration of 77.5%. Multivariate analysis showed that the time slope-log PSA, the time from the previous cycle, and the response to the previous cycle were predictive of the response to a rechallenge.
A docetaxel rechallenge may be safely repeated several times in CRPC patients and in selected patients could improve disease control. The predictive factors found in our analysis may help select the most appropriate strategy in the light of the availability of active second-line drugs.