Background: We investigated our institution’s mCRPC enzalutamide or abiraterone patients examining
PSA responses and impact of sequencing of these drugs.
Methods: All enzalutamide / abiraterone mCRPC patients (2011-2018) were included. Rates of PSA >50%
response (PSA50) were compared. Time to treatment failure (TTF) and overall survival (OS) was analysed
as per lines of previous therapy and timing of chemotherapy.
Results: 363 patients included (Enza n=236, Abi n=127), with 15.6 months median follow-up. PSA50 was
greater in enzalutamide group (58% vs 31% p<0.0005) but TTF was similar for both groups (median Abi
4.2m vs Enza 6m, p=0.965). There was no significant median OS difference between the groups (Enza
13.8m vs Abi 12.5m p=0.065). Number of lines of prior therapy (p=0.735) or timing of chemotherapy before
or after Abi/Enza (p=0.21) had no significant OS impact.
Conclusion: Enzalutamide showed higher PSA50 response than abiraterone. Previous lines of therapy or
sequencing of chemotherapy with abiraterone / enzalutamide showed no significant survival differences
indicating no detriment in either treatment sequence.
Objective: Enzalutamide is effective in treating metastatic castrate-resistant prostate cancer (mCRPC) but can have side effects that require treatment breaks (TB). We conducted a retrospective analysis of outcomes of patients who had extended TB due to toxicity compared to continuous dosing. Methods: Patients prescribed enzalutamide for mCRPC from September 2011 to February 2018 were included. TB was defined as an interruption of four weeks or more. Overall survival (OS) from enzalutamide start, time to prostate-specific antigen failure (TTF) and total enzalutamide treatment time (TTT) were analysed for TB and continuous responders (>50% PSA drop), and a significance level of 0.05 was assigned. Results: A total of 110 patients were continuous responders, and 29 had TB. The median number of interruptions was one (range 1–7), and time on treatment was 70% in the TB group. The TB group had significantly improved OS (100 vs. 60 months; hazard ratio=1.8, 95% confidence interval 1.17–2.77, p=0.02), prolonged TTF (median 11 vs. 6 months; p=0.008) and TTT (median 15 vs. 8 months; p=0.0001). Conclusion: Extended TB do not seem to impact OS or treatment duration adversely in patients who are responding and experiencing toxicity, and may be a useful option in managing toxicity. Prospective trials could explore this further. Level of evidence: Level 2c.
The results of a series of non-randomized studies suggest that complete androgen blockade, i.e. medical or surgical castration in association with an antiandrogen, is superior to castration alone as regard survival potential. This report presents 11 untreated patients (Stage T2-4, Nx, M1), who were treated with complete androgen blockade, orchiectomy and a pure antiandrogen (Flutamide 250 mg three times a day). The rate of subjective response was 100% and the median time to progression was 12 months. The objective response rate was 82% and the rates of partial remission at one and two years were 45% and 18%, respectively. The survival rates after one and two years were 91% and 53%, respectively, a result which is consistent with that of other studies on the survival of patients with metastatic cancer of the prostate treated with either diethylstilboestrol, orchiectomy or LH-releasing hormones. The results of this study do not support the hypothesis that androgen blockade improves the survival of patients with advanced metastatic cancer of the prostate.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.