Objectives
Previous studies have demonstrated that intravesical
administration of apaziquone (EOquin) has ablative activity against superficial
bladder cancer marker lesions with 8 out of 12 complete responses recorded. We
present a comparison between the rates of tumor recurrence before and after
treatment with apaziquone.
Methods
The rate of tumor recurrence after treatment with apaziquone was
compared with each patient's historical record of recurrences obtained from a
retrospective analysis of the patients' case notes. The time to each recurrence
event before apaziquone treatment and the time to the first recurrence after
apaziquone treatment were recorded, and the data were analyzed using a
population-averaged linear regression model using Stata Release, version 9.2,
software.
Results
Of the eight complete responses
obtained in the Phase I study, tumor recurrence occurred in 4 patients and the
remaining 4 patients remained disease free after a median follow-up of 31
months. The time to the first recurrence after apaziquone treatment was
significantly longer (P <0.001) compared with the
historical pattern and recurrence interval before apaziquone. Before apaziquone
instillation, the mean ± SE recurrence rate and tumor rate per year was 1.5 ±
0.2 and 4.8 ± 1.2, respectively, and these decreased to 0.6 ± 0.25 and 1.5 ±
0.8, respectively, after apaziquone treatment (P <0.05).
Conclusions
The results of this study indicate that early recurrences after
treatment with apaziquone are infrequent and the interval to recurrence is
significantly greater compared with the historical recurrence times for these
patients. Larger prospective randomised trials are warranted to confirm these
results.
