Abiraterone in Metastatic Prostate Cancer without Previous Chemotherapy.

The authors' affiliations are listed in the Appendix.
New England Journal of Medicine (Impact Factor: 54.42). 12/2012; DOI: 10.1056/NEJMoa1209096
Source: PubMed

ABSTRACT Background Abiraterone acetate, an androgen biosynthesis inhibitor, improves overall survival in patients with metastatic castration-resistant prostate cancer after chemotherapy. We evaluated this agent in patients who had not received previous chemotherapy. Methods In this double-blind study, we randomly assigned 1088 patients to receive abiraterone acetate (1000 mg) plus prednisone (5 mg twice daily) or placebo plus prednisone. The coprimary end points were radiographic progression-free survival and overall survival. Results The study was unblinded after a planned interim analysis that was performed after 43% of the expected deaths had occurred. The median radiographic progression-free survival was 16.5 months with abiraterone-prednisone and 8.3 months with prednisone alone (hazard ratio for abiraterone-prednisone vs. prednisone alone, 0.53; 95% confidence interval [CI], 0.45 to 0.62; P<0.001). Over a median follow-up period of 22.2 months, overall survival was improved with abiraterone-prednisone (median not reached, vs. 27.2 months for prednisone alone; hazard ratio, 0.75; 95% CI, 0.61 to 0.93; P=0.01) but did not cross the efficacy boundary. Abiraterone-prednisone showed superiority over prednisone alone with respect to time to initiation of cytotoxic chemotherapy, opiate use for cancer-related pain, prostate-specific antigen progression, and decline in performance status. Grade 3 or 4 mineralocorticoid-related adverse events and abnormalities on liver-function testing were more common with abiraterone-prednisone. Conclusions Abiraterone improved radiographic progression-free survival, showed a trend toward improved overall survival, and significantly delayed clinical decline and initiation of chemotherapy in patients with metastatic castration-resistant prostate cancer. (Funded by Janssen Research and Development, formerly Cougar Biotechnology; number, NCT00887198 .).

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    ABSTRACT: Targeting androgen receptor (AR) axis signaling by disrupting androgen-AR interactions remains the primary treatment for metastatic prostate cancer. Unfortunately, all men develop resistance to primary castrating therapy and secondary androgen deprivation therapies (ADTs). Resistance develops in part because castration-resistant prostate cancer (CRPC) cells adaptively up-regulate AR levels through overexpression, amplification, and expression of ligand-independent variants in response to chronic exposure to a low-testosterone environment. However, preclinical models suggest that AR overexpression represents a therapeutic liability that can be exploited via exposure to supraphysiologic testosterone to promote CRPC cell death. Preclinical data supported a pilot study in which 16 asymptomatic CRPC patients with low to moderate metastatic burden were treated with testosterone cypionate (400 mg intramuscular; day 1 of 28) and etoposide (100 mg oral daily; days 1 to 14 of 28). After three cycles, those with a declining prostate-specific antigen (PSA) continued on intermittent testosterone therapy monotherapy. Castrating therapy was continued to suppress endogenous testosterone production, allowing for rapid cycling from supraphysiologic to near-castrate serum testosterone levels, a strategy termed bipolar androgen therapy (BAT). BAT was well tolerated and resulted in high rates of PSA (7 of 14 evaluable patients) and radiographic responses (5 of 10 evaluable patients). Although all men showed eventual PSA progression, four men remained on BAT for ≥1 year. All patients (10 of 10) demonstrated PSA reductions upon receiving androgen-ablative therapies after BAT, suggesting that BAT may also restore sensitivity to ADTs. BAT shows promise as treatment for CRPC and should be further evaluated in larger trials. Copyright © 2015, American Association for the Advancement of Science.
    Science translational medicine 01/2015; 7(269):269ra2-269ra2. DOI:10.1126/scitranslmed.3010563 · 14.41 Impact Factor
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    ABSTRACT: Metastatic castration-resistant prostate cancer is the lethal form of cancer of the prostate. Five new agents that prolong survival in this group have emerged in the past 5 years, and sipuleucel-T is among them. Sipuleucel-T is the only immunotherapy shown to improve survival in prostate cancer. It is currently indicated in asymptomatic or mildly symptomatic patients, as it has never shown a direct cancer effect. This paper describes the process of creating the sipuleucel-T product from the manufacturing and patient aspects. It discusses the four placebo-controlled, randomized clinical trials (RCTs) of sipuleucel-T, focusing on survival and adverse events. There are three RCTs in metastatic castration-resistant prostate cancer, all of which showed improved overall survival without meaningful decreases in symptoms, tumor volumes, or prostate-specific antigen levels. One RCT in castration-sensitive, biochemically relapsed prostate cancer attempted to find a decrease in biochemical failure, but that endpoint was not reached. Adverse events in all four of these studies centered around cytokine release. This paper also reviews a Phase II study of sipuleucel-T given neoadjuvantly that speaks to its mechanism of action. Additionally, there is a registry study of sipuleucel-T that has been used to evaluate immunological parameters of the product in men ≥80 years of age and men who had previously been treated with palliative radiation. Attempts to find early markers of response to sipuleucel-T are described. Further ongoing studies that explore the efficacy of sipuleucel-T in combination with immune checkpoint inhibitors and second-generation hormonal therapies that are summarized. Finally, the only published economic analysis of sipuleucel-T is discussed.
    Core Evidence 01/2015; 10:1-10. DOI:10.2147/CE.S54712
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    ABSTRACT: The aim of this paper was to evaluate the activity and tolerability of weekly docetaxel (D) combined with weekly epirubicin (EPI) in patients with advanced castrate-resistant prostate cancer (CRPC) previously exposed to D and abiraterone acetate (AA). Locally advanced or metastatic CRPC patients with 0-2 performance status, who had progressed after D and AA therapy, were included in the study. Previous treatment with chemotherapy agent cabazitaxel was also admitted. Treatment consisted of D 30 mg/m(2) intravenously (i.v.) and EPI 30 mg/m(2) i.v., every week (D/EPI). Chemotherapy was administered until disease progression or unacceptable toxicity. In our institution, twenty-six patients received D/EPI: their median age was 72 years (range 59-83 years). Twenty-three (88.5 %) patients had bone metastases. A decrease in PSA levels ≥50 % was observed in seven patients (26.9 %, 95 % CI: 0.11-0.47); of these, five had achieved a ≥50 % PSA response during prior first-line D and six had achieved a PSA response during prior AA Among the subjects who were symptomatic at baseline, pain was reduced in nine patients (38.1 %) with a significant decrease in analgesic use. Median progression-free survival was 4.4 months (95 % CI, 3-5.2), and median overall survival was 10.7 months (95 % CI, 8.9-18.4). Treatment was well tolerated and no grade 4 toxicities were observed. Our findings suggest that weekly D/EPI is feasible and active in heavily pretreated advanced CRPC patients and seem to support the hypothesis that the addition of EPI to D may lead to overcome the resistance to D in a subgroup of patients.

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