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 ◽  
...  

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]

2017 ◽  
Vol 12 (2) ◽  
pp. E47-52 ◽  
Author(s):  
Daniel Joseph Khalaf ◽  
Claudia M. Avilés ◽  
Arun A. Azad ◽  
Katherine Sunderland ◽  
Tilman Todenhöfer ◽  
...  

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.


2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 99-99 ◽  
Author(s):  
Bo Zhao ◽  
Jorge A. Garcia ◽  
Timothy D. Gilligan ◽  
Brian I. Rini ◽  
Robert Dreicer

99 Background: Studies have shown activity of Abiraterone acetate (AA) in patients (pts) with castration-resistant prostate cancer (CRPC) who have received prior ketoconazole. Prostate-specific antigen (PSA) response to AA in relation to previous PSA response to ketoconazole was investigated. Methods: A retrospective analysis was conducted to determine the clinical activity of AA in men with CRPC who have received prior ketoconazole therapy at our institution. Time to PSA progression (PSA TTP) was defined by PCWG2 criteria, a PSA reduction of 50% or more was considered as PSA response. Results: Thirty four pts were identified. Nineteen pts (56%) had previous PSA responses on ketoconazole, with a median PSA TTP of 11 months (95% confidence interval [CI] 6.8-19.9). Subsequently, 11 of 34 (33%) of pts achieved a PSA response on AA, with a median PSA TTP of 6 months (95% CI 4.9-9.5). Among the 19 pts having a PSA response on ketoconazole, only four (21%) pts subsequently had PSA response to AA. Two of these pts had transient PSA response with PSA TTP less than 3 months on kKetoconazole, one patient discontinued Ketoconazole due to side effects, one patient had intermittent non-castrate testosterone levels. In contrast, 7 of 15 (46.7%) pts without prior PSA response to ketoconazole subsequently achieved PSA response on AA (p=0.11). Of note, PSA reduction of less than 50% on AA was observed in 9 of 34 pts (26%), which was associated with a longer median PSA TTP compared to pts who had PSA-progressive disease (5.9 months [95% CI 3.5-7.3] vs.1.5 months [95% CI 1.0-3.5], p=0.028). Five of these nine patients had a prior PSA response to ketoconazole but required drug discontinuation for reasons other than disease progression. Conclusions: PSA response to prior ketoconazole therapy is associated with lower PSA response rate to subsequent AA. The observation suggests that there is a biologically distinct subset of patients who are ketoconazole-resistant but abiraterone-sensitive, the underlying mechanism needs to be further investigated.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 5040-5040
Author(s):  
Rana R. McKay ◽  
Lillian Werner ◽  
Alexandra Jones ◽  
Atish Dipankar Choudhury ◽  
Mark Pomerantz ◽  
...  

5040 Background: AA blocks CYP17 and suppresses adrenal androgens and glucocorticoids. Given the risk of mineralocorticoid excess (ME), AA is administered with corticosteroids. In this phase II multicenter, single-arm study, we assess the safety of AA without steroids in CRPC. The primary objective is to determine the proportion of men requiring prednisone to manage ME. Methods: Eligible patients had CRPC with controlled blood pressure (BP) ( < 140/90 on ≤3 agents) and a normal or ≥3.5 mmol/L potassium. Patients initially received AA (1000 mg daily) alone. Patients who developed a BP ≥ 140/90 were treated with anti-hypertensives (HTN) and/or a mineralocorticoid antagonist (MA) prior to steroids. Hypokalemia was treated with supplementation or a MA. Patients with persistent or severe ME were initiated on prednisone (5 mg twice daily). To assess response to steroids, prednisone was added to AA at PSA progression. Therapy was continued until radiographic progression, toxicity, or withdrawal. Results: 60 patients were enrolled of whom 51 (83%) had metastases 16 (27%) received prior chemotherapy, 6 (10%) enzalutamide, and 4 (7%) ketoconazole. Grade (G) 3-4 adverse events (AEs) of interest included HTN (G3 n = 8, 13%; G4 n = 1, 2%), hypokalemia (G3 n = 4, 7%; G4 n = 0), fatigue (G3 n = 1, 2%; G4 n = 0). There was no G ≥3 edema. 9 patients (15%) initiated prednisone for toxicity: HTN (n = 3, 5%), hypokalemia (n = 4, 7%), fatigue (n = 2, 3%). Baseline PSA was 15.4 ng/mL. Time to nadir PSA was 2.5 months (IQR 1.4, 6.3) and median nadir PSA was 2.1 ng/mL. 67% of patients (n = 40) experienced a ≥50% PSA decline and 35% (n = 21) experienced a ≥90% decline. 19 patients (32%) initiated prednisone for PSA progression. Median time to prednisone initiation in patients with PSA progression was 6.1 months (IQR 4.9, 11.7); 5 patients (8.3%) had a PSA decline and 1 achieved a ≥50% decline. Levels of corticosteroids will be reported. Conclusions: In CRPC, AA without steroids is feasible, however clinically significant AEs, particularly HTN, can occur in a minority of patients. HTN and hypokalemia can be treated with anti-HTN agents or potassium without steroids in the majority. Use of AA without prednisone needs to be balanced with the potential risk of toxicity. Clinical trial information: NCT02025010.


2010 ◽  
Vol 28 (9) ◽  
pp. 1489-1495 ◽  
Author(s):  
Alison H.M. Reid ◽  
Gerhardt Attard ◽  
Daniel C. Danila ◽  
Nikhil Babu Oommen ◽  
David Olmos ◽  
...  

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.


2018 ◽  
Vol 36 (25) ◽  
pp. 2639-2646 ◽  
Author(s):  
Gerhardt Attard ◽  
Michael Borre ◽  
Howard Gurney ◽  
Yohann Loriot ◽  
Corina Andresen-Daniil ◽  
...  

Purpose Enzalutamide resistance could result from raised androgens and be overcome by combination with abiraterone acetate. PLATO ( ClinicalTrials.gov identifier: NCT01995513) interrogated this hypothesis using a randomized, double-blind, placebo-controlled design. Patients and Methods In period one, men with chemotherapy-naïve metastatic castration-resistant prostate cancer received open-label enzalutamide 160 mg daily. Men with no prostate-specific antigen (PSA) increase at weeks 13 and 21 were treated until PSA progression (≥ 25% increase and ≥ 2 ng/mL above nadir), then randomly assigned at a one-to-one ratio in period two to abiraterone acetate 1,000 mg daily and prednisone 5 mg twice daily with either enzalutamide or placebo (combination or control group, respectively) until disease progression as defined by the primary end point: progression-free survival (radiographic or unequivocal clinical progression or death during study). Secondary end points included time to PSA progression and PSA response in period two. Results Of 509 patients enrolled in period one, 251 were randomly assigned in period two. Median progression-free survival was 5.7 months in the combination group and 5.6 months in the control group (hazard ratio, 0.83; 95% CI, 0.61 to 1.12; P = .22). There was no difference in the secondary end points. Grade 3 hypertension (10% v 2%) and increased ALT (6% v 2%) or AST (2% v 0%) were more frequent in the combination than the control group. Conclusion Combining enzalutamide with abiraterone acetate and prednisone is not indicated after PSA progression during treatment with enzalutamide alone; hypertension and elevated liver enzymes are more frequent with combination therapy.


2016 ◽  
Vol 34 (2_suppl) ◽  
pp. 261-261 ◽  
Author(s):  
Gerhardt Attard ◽  
Axel S. Merseburger ◽  
Cora N. Sternberg ◽  
Linda Cerbone ◽  
Federica Recine ◽  
...  

261 Background: AA is approved for mCRPC, coadministered with prednisone (P) (5 mg BID) to prevent adverse events (AEs) associated with mineralocorticoid excess (ME). Lower GC doses had not previously been formally evaluated in combination with AA. Methods: This was an open-label, multicenter, phase 2 trial (NCT01867710) of asymptomatic chemotherapy-naïve mCRPC pts randomized 1:1:1:1 to AA (1000 mg QD) plus P 5 mg BID or P 5 mg QD or P 2.5 mg BID or dexamethasone (DEX) 0.5 mg QD. Pts who had previously received GC or ketoconazole were excluded. The primary end point was no ME (% of pts experiencing neither hypokalemia nor hypertension during the first 24 weeks of treatment).Secondary end points included additional safety, as well as response rate in the first 24 weeks, defined as a decline in prostate-specific antigen (PSA) ≥ 50% confirmed after 4 weeks. Results: 164 pts were randomized; 133 (81.6%) completed 24 weeks’ treatment. Median age: 70 years. Table 1 shows the rates of ME, hypertension, hypokalemia and PSA response. Changes in HbA1c values were minimal and observed in 16 (10.7%) pts. Conclusions: These data suggest that P 5 mg BID, which is approved in combination with AA, and DEX 0.5 mg QD, are effective in preventing ME-associated AEs, and that P 2.5 mg BID and P 5 mg QD can be safely used with appropriate monitoring. The suggestion of a higher PSA response rate with DEX 0.5 mg QD arm warrants further validation. Clinical trial information: NCT01867710. [Table: see text]


2020 ◽  
Vol 6 (2) ◽  
pp. FSO436 ◽  
Author(s):  
Cecília M Alvim ◽  
André Mansinho ◽  
Rita S Paiva ◽  
Raquel Brás ◽  
Patrícia M Semedo ◽  
...  

Aim: To evaluate prostate-specific antigen response (PSAr) defined as a ≥50% decrease in PSA concentration from the pretreatment value, as a prognostic factor in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with abiraterone acetate (AA). Methods: Retrospective evaluation of patients with mCRPC treated with AA. Results: 124 patients were identified. Median overall survival and progression-free survival for patients achieving PSAr versus patients without PSAr were 29.3 versus 9.7 months and 17.0 versus 5.2 months, respectively. Multivariate analysis confirmed that PSAr correlated with better overall survival (hazard ratio: 0.19; 95% CI: 0.10−0.38; p < 0.001) and progression-free survival (hazard ratio: 0.24; 95% CI: 0.14−0.41; p < 0.001). Conclusion: PSAr can be utilized as prognostic and predictive factors in mCRPC patients treated with AA.


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