Phase II multicenter study of abiraterone acetate (AA) plus prednisone therapy in docetaxel-treated castration-resistant prostate cancer (CRPC) patients (pts): Impact of prior ketoconazole (keto)

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 5048-5048 ◽  
Author(s):  
D. C. Danila ◽  
J. de Bono ◽  
C. J. Ryan ◽  
S. Denmeade ◽  
M. Smith ◽  
...  
Keyword(s):  
Abiraterone Acetate ◽  
Phase Iii ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant ◽  
Pivotal Study ◽  
Heavily Pretreated ◽  
Psa Progression ◽  
Hormonal Therapies ◽  
Ecog Ps ◽  
Anti Tumor Activity

5048 Background: AA is a potent blocker of CYP17, required for synthesis of testosterone in the testes, adrenals, and prostate tissue. Study objectives included confirming AA antitumor activity and safety in multicenter setting, describing changes in ECOG PS, and comparing keto-naïve pts to keto-exposed pts. Methods: The 58 pts had progressive, metastatic CRPC and had failed hormonal therapy and up to two cytotoxic regimens, including docetaxel. AA (1,000 mg QD) and prednisone (5mg BID) were administered daily, the registration trial regimen. 56/58 pts had available data. Results: Baseline demographics: median age - 69.0 (44–86) yrs; median PSA - 151.00 (10.0–3846.0) ng/mL; ECOG 0 (n = 23), 1 (n = 30), 2 (n = 2), missing (n = 1); median prior hormonal therapies were 4 and chemo 1; 24 pts had prior keto, 32 pts were keto-naïve and 2 pts had no data on keto exposure. 45% pts had total maximal PSA decline ≥50%. Total maximal PSA decline (≥30%, ≥50% and ≥90%) in prior keto vs. keto-naïve pts was observed respectively, in: 10 (42%) vs. 20 (63%) pts; 8 (33%) vs. 17 (53%); 1 (4%) vs. 10 (31%). From 32 pts with ECOG 1 or 2, 16 pts (50%, 95% CI 32–68) improved (PS 1 to 0 in 14 pts, PS 2 to 1 in 1 pt; PS 2 to 0 in 1 pt); 39 pts (64% of total 58 pts) maintained PS. Median time to PSA progression was 169 days (95% CI 82–200): keto-naïve-198 days, prior keto-99 days. The majority of AA-related adverse events (AEs) were grade 1–2. No AA-related grade 4 AE was noted. Conclusions: Abiraterone acetate was well-tolerated and produced anti-tumor activity in heavily pretreated pts, as evidenced by PSA declines and improved PS. Incidence of mineralocorticoid-related AEs (HTN or hypokalemia) was reduced with the addition of low-dose prednisone. The keto-naïve post-docetaxel CRPC population was selected for the ongoing phase III pivotal study to confirm these results. [Table: see text]

scholarly journals Significant and Sustained Antitumor Activity in Post-Docetaxel, Castration-Resistant Prostate Cancer With the CYP17 Inhibitor Abiraterone Acetate

2010 ◽  
Vol 28 (9) ◽  
pp. 1489-1495 ◽  
Author(s):  
Alison H.M. Reid ◽  
Gerhardt Attard ◽  
Daniel C. Danila ◽  
Nikhil Babu Oommen ◽  
David Olmos ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Antitumor Activity ◽  
Phase Ii ◽  
Specific Antigen ◽  
Abiraterone Acetate ◽  
Phase Iii ◽  
Castration Resistant Prostate Cancer ◽  
End Point ◽  
Castration Resistant ◽  
Psa Progression

Purpose The principal objective of this trial was to evaluate the antitumor activity of abiraterone acetate, an oral, specific, irreversible inhibitor of CYP17 in docetaxel-treated patients with castration-resistant prostate cancer (CRPC). Patients and Methods In this multicenter, two-stage, phase II study, abiraterone acetate 1,000 mg was administered once daily continuously. The primary end point was achievement of a prostate-specific antigen (PSA) decline of ≥ 50% in at least seven of 35 patients. Per an attained phase II design, more than 35 patients could be enrolled if the primary end point was met. Secondary objectives included: PSA declines of ≥ 30% and ≥ 90%; rate of RECIST (Response Evaluation Criteria in Solid Tumors) responses and duration on study; time to PSA progression; safety and tolerability; and circulating tumor cell (CTC) enumeration. Results Docetaxel-treated patients with CRPC (N = 47) were enrolled. PSA declines of ≥ 30%, ≥ 50% and ≥ 90% were seen in 68% (32 of 47), 51% (24 of 47), and 15% (seven of 47) of patients, respectively. Partial responses (by RECIST) were reported in eight (27%) of 30 patients with measurable disease. Median time to PSA progression was 169 days (95% CI, 113 to 281 days). The median number of weeks on study was 24, and 12 (25.5%) of 47 patients remained on study ≥ 48 weeks. CTCs were enumerated in 34 patients; 27 (79%) of 34 patients had at least five CTCs at baseline. Eleven (41%) of 27 patients had a decline from at least five to less than 5 CTCs, and 18 (67%) of 27 had a ≥ 30% decline in CTCs after starting treatment with abiraterone acetate. Abiraterone acetate was well tolerated. Conclusion Abiraterone acetate has significant antitumor activity in post-docetaxel patients with CRPC. Randomized, phase III trials of abiraterone acetate are underway to define the future role of this agent.

A multicenter phase II study of abiraterone acetate (AA) in docetaxel pretreated castration-resistant prostate cancer (CRPC) patients (pts)

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 5047-5047
Author(s):  
A. H. Reid ◽  
G. Attard ◽  
D. Danila ◽  
C. J. Ryan ◽  
E. Thompson ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Abiraterone Acetate ◽  
Phase Iii ◽  
Castration Resistant Prostate Cancer ◽  
Patient Demographics ◽  
Castration Resistant ◽  
Heavily Pretreated ◽  
Key Enzyme ◽  
Psa Response ◽  
Docetaxel Chemotherapy

5047 Background: Despite castration, androgens remain critical to prostate cancer. Abiraterone acetate (AA) specifically and irreversibly inhibits CYP17, a key enzyme in androgen biosynthesis. Methods: 47 CRPC pts who had failed androgen deprivation therapy and had prior docetaxel chemotherapy received AA orally (1000mg QD) in 28 day cycles. Low dose glucocorticoids were allowed. Results: Patient demographics in table . Total maximal PSA declines with AA at any point on study of ≥30%, ≥50%, and ≥ 90% were observed in 32 (69%), 24 (51%) and 7 (15%) pts respectively. A similar trend in PSA response was seen at wk 12. 35 pts were evaluable by RECIST; 6 (17%) pts had a partial response and 23 (66%) pts had stable disease. 23% of pts showed ECOG improvement (PS 1 to 0 in 10 pts, PS 2 to 1 in 1 pt); 53% of pts maintained PS. Median duration on treatment was 167 days (95% CI 130–201). 17 pts received >6 cycles of AA; 8 pts received ≥ 12 cycles. Toxicities related to mineralocorticoid excess were mainly grade 1–2 (hypokalemia 51%; HTN 17%; edema 13%) and were treated with eplerenone or corticosteroids. Conclusions: AA has anti-tumor activity in these heavily pretreated pts, as evidenced by sustained PSA declines, improvement in PS and RECIST responses. A phase III trial assessing the efficacy and safety of AA and prednisone in CRPC pts who have failed docetaxel chemotherapy is underway. [Table: see text] [Table: see text]

scholarly journals A prognostic model for stratifying clinical outcomes in chemotherapy-naive metastatic castration-resistant prostate cancer patients treated with abiraterone acetate

2017 ◽  
Vol 12 (2) ◽  
pp. E47-52 ◽  
Author(s):  
Daniel Joseph Khalaf ◽  
Claudia M. Avilés ◽  
Arun A. Azad ◽  
Katherine Sunderland ◽  
Tilman Todenhöfer ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Clinical Outcomes ◽  
Group Performance ◽  
Eastern Cooperative Oncology Group ◽  
Specific Antigen ◽  
Prognostic Index ◽  
Abiraterone Acetate ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant ◽  
Psa Progression

Introduction: Recently, a prognostic index including six risk factors (RFs) (unfavourable Eastern Cooperative Oncology Group performance status [ECOG PS], presence of liver metastases, short response to luteinizing hormone-releasing hormone [LHRH] agonists/ antagonists, low albumin, increased alkaline phosphatase [ALP] and lactate dehydrogenase [LDH]) was developed from the COUAA- 301 trial in post-chemotherapy metastatic castration-resistant prostate cancer (mCRPC) patients treated with abiraterone acetate. Our primary objective was to evaluate this model in a cohort of chemotherapy-naive mCRPC patients receiving abiraterone.Methods: We identified 197 chemotherapy-naive patients who received abiraterone at six BC Cancer Agency centres and who had complete information on all six RFs. Study endpoints were prostate-specific antigen (PSA) response rate (RR), time to PSA progression, time on treatment, and overall survival (OS). PSA RR and survival outcomes were compared using Χ2 test and log-rank test. Multivariable Cox proportional hazard analysis was performed to identify RFs independently associated with OS.Results: Patients were classified into good (0‒1 RFs), intermediate (2‒3 RFs), and poor (4‒6 RFs) prognostic groups (33%, 52%, and 15%, respectively). For good-, intermediate-, and poor-risk patients, PSA RR (≥50% decline) was 60% vs. 42% vs. 40% (p=0.05); median time to PSA progression was 7.3 vs. 5.3 vs. 5.0 months (p=0.02); and median OS was 29.4 vs. 13.8 vs. 8.7 months (p<0.0001).Conclusions: The six-factor prognostic index model stratifies clinical outcomes in chemotherapy-naive mCRPC patients treated with abiraterone. Identifying patients at risk of poor outcome is important for informing clinical practice and clinical trial design.

Androgen Receptor Rediscovered: The New Biology and Targeting the Androgen Receptor Therapeutically

2011 ◽  
Vol 29 (27) ◽  
pp. 3651-3658 ◽  
Author(s):  
Charles J. Ryan ◽  
Donald J. Tindall
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Clinical Success ◽  
Abiraterone Acetate ◽  
Clinical Findings ◽  
Phase Iii ◽  
Clinical Activity ◽  
Castration Resistant Prostate Cancer ◽  
Androgen Synthesis ◽  
Castration Resistant

Discoveries over the past decade suggest that castration-resistant prostate cancer (CRPC) is sensitive, but not resistant to, further manipulation of the androgen–androgen receptor (AR) axis. Several new therapies that target this axis have demonstrated clinical activity. In this article, preclinical and clinical findings occurring in the field of AR-targeted therapies are reviewed. Reviews of scientific and clinical development are divided into those occurring prereceptor (androgen production and conversion) and at the level of the receptor (AR aberrations and therapies targeting AR directly). Intracrine androgen production and AR amplification, among others, are among the principal aberrancies driving CRPC growth. Phase III data with abiraterone acetate and phase II data with MDV-3100, along with other similar therapies, confirm for the clinician that the scientific findings related to persistent AR signaling in a castrate milieu can be harnessed to produce significant clinical benefit for patients with the disease. Studies aimed at optimizing the timing of their use and exploring the mechanisms of resistance to these therapies are under way. The clinical success of therapies that directly target androgen synthesis as well as the most common aberrancies of the AR confirm that prostate cancer retains dependence on AR signaling, even in the castrate state.

scholarly journals Minireview: Androgen Metabolism in Castration-Resistant Prostate Cancer

2013 ◽  
Vol 27 (5) ◽  
pp. 708-714 ◽  
Author(s):  
Nima Sharifi
Keyword(s):  
Prostate Cancer ◽  
Abiraterone Acetate ◽  
Castration Resistant Prostate Cancer ◽  
Synthesis Inhibitor ◽  
Androgen Independence ◽  
Androgen Synthesis ◽  
Androgen Receptor Antagonist ◽  
Castration Resistant ◽  
Hormonal Therapies ◽  
Additional Clinical Benefit

Abstract The decades-old terminology of androgen independence has been replaced in recent years with castration-resistant prostate cancer. Biological and clinical evidence have together conspired to support the use of this revised terminology by demonstrating that in the vast majority of cases tumors are neither truly depleted of androgens, nor are they free of the requirement for androgens to sustain growth and progression. Abiraterone acetate, an androgen synthesis inhibitor, and enzalutamide, a potent androgen receptor antagonist, both exploit the continued requirement for androgens. A central question, given the therapeutic gains enabled by further suppression of the androgen axis with these newer agents, is whether there may be additional clinical benefit gained by moving the goal posts of androgen suppression even further. The answer lies in part with the mechanisms utilized by tumors that enable resistance to these therapies. The aims of this review were to give a broad outline of steroidogenesis in prostate cancer and to highlight recent developments in understanding resistance to hormonal therapies.

Novel therapies and emerging strategies for the treatment of patients with castration-resistant prostate cancer

2017 ◽  
Author(s):  
Deborah Mukherji ◽  
Aurelius Omlin ◽  
Carmel Pezaro ◽  
Johann De Bono
Keyword(s):  
Prostate Cancer ◽  
Abiraterone Acetate ◽  
Phase Iii ◽  
Trial Participation ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant ◽  
Radium 223 ◽  
New Treatments ◽  
Phase Iii Studies ◽  
Clinical And Translational Research

Castration-resistant prostate cancer (CRPC) represents a final stage of this malignancy for many men and is defined as the progression of prostate cancer despite castrate levels of testosterone. CRPC may present as a rising PSA, the development of new metastases, or worsening of known metastases. Recent advances have resulted in five new treatments for CRPC: the immunotherapy sipuleucel-T; the cytotoxic cabazitaxel; the androgen biosynthesis inhibitor abiraterone acetate; the radioisotope radium-223; and the antiandrogen enzalutamide. These have all improved overall survival in randomized phase III studies for patients with metastatic CRPC. Furthermore, multiple agents and combinations are currently in late-stage clinical testing. Men with advanced prostate cancer represent an important population for clinical and translational research and clinical trial participation should be considered as part of standard care.

Recent Developments in Treatments for Metastatic Castration-resistant Prostate Cancer—A Mechanistic Perspective

2012 ◽  
Vol 08 (02) ◽  
pp. 89
Author(s):  
Guru Sonpavde ◽  
E David Crawford ◽  
◽  
Keyword(s):  
Prostate Cancer ◽  
Abiraterone Acetate ◽  
Chemotherapeutic Agents ◽  
New Drugs ◽  
Phase Iii ◽  
Castration Resistant Prostate Cancer ◽  
Microtubule Inhibitor ◽  
Phase Iii Clinical Trials ◽  
Castration Resistant ◽  
Radium 223

Over the past decade, the treatment landscape in metastatic castration-resistant prostate cancer (CRPC) has markedly changed, with the introduction of three new chemotherapeutic agents. The mechanism of CRPC is not fully understood, but it may result from multiple pathways, including a loss or androgen receptor (AR) specificity and increased downstream signalling activity that provide multiple targets for therapeutic agents. For some years, docetaxel was the mainstay of treatment in CRPC, but recently, cabazitaxel (a microtubule inhibitor), sipuleucel-T (a cancer vaccine), and abiraterone acetate (a CYP17 inhibitor) were approved for CRPC treatment. In Phase III clinical trials, these agents have shown significant improvements in survival—over mitoxantrone (for cabazitaxel) and over placebo (for sipuleucel-T and abiraterone acetate)—and were well tolerated. There are also two treatments in late-stage development, MDV3100 (an oral AR antagonist) and radium-223 (an isotope that creates breaks in double-stranded DNA). These have also shown improvements in survival in Phase III trials; their regulatory approval is expected soon. The modes of actions of the existing and new drugs in CRPC are varied, but some are complementary and investigations of different combinations of these medications are much needed; they may enhance efficacy, further extend survival, and improve outcomes in this formerly untreatable disease.

Evaluating the safety of abiraterone acetate (AA) and docetaxel (D) administered in combination in patients (Pts) with metastatic castration-resistant prostate cancer (mCRPC).

2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 205-205 ◽  
Author(s):  
Scott T. Tagawa ◽  
David M. Nanus ◽  
Edwin M. Posadas ◽  
Daniel Peter Petrylak ◽  
Justine Yang Bruce ◽  
...  
Keyword(s):  
Specific Antigen ◽  
Systemic Exposure ◽  
Abiraterone Acetate ◽  
Maximum Plasma ◽  
Castration Resistant Prostate Cancer ◽  
Time Curve ◽  
Castration Resistant ◽  
Psa Progression ◽  
Dose Limiting Toxicity ◽  
Clinical Trial Information

205 Background: D and AA may have complementary mechanisms of action; coadministration may be beneficial. A phase Ib study assesses the safety of escalating doses of D + AA. Methods: Up to4 cohorts (C) of chemo-naïve mCRPC pts would receive D + AA. Data for C1 and C2 are presented. Primary end point: proportion of pts with dose-limiting toxicity (DLT) between Wks 2 and 7, defined as grade (Gr) ≥ 3 non-heme toxicity, Gr 4 neutropenia (absolute neutrophil count < 500/mm3) > 7 days (or febrile neutropenia), Gr 4 thrombocytopenia, or other intolerable toxicity. D + AA was deemed safe if ≤ 33% of pts experienced DLT. Pharmacokinetic (PK) parameters were evaluated for D and AA alone and in combination. Results: 15 pts were treated and 6 pts/C were evaluable for DLT assessment. 2 DLTs were observed in C1, and 1 in C2. 73% and 87% of pts had confirmed ≥ 90% and ≥ 50% prostate-specific antigen (PSA) decline, respectively. Median time to PSA progression has not yet been reached. Systemic exposure, based on maximum plasma concentration (Cmax) and area under the concentration–time curve [(AUC)∞ for D, AUC24 for abiraterone (ABI)], was comparable for both D and AA alone and for D + AA. 3 pts in C3 (D 75 mg/m2+ AA 1000 mg) have been treated past Wk 7 without DLT. Conclusions: D + AA was well tolerated in the cohorts tested. Preliminary results justify further evaluation of safety and efficacy in additional Cs. Clinical trial information: NCT01400555. [Table: see text]

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