Niraparib plus abiraterone acetate with prednisone in patients with metastatic castration-resistant prostate cancer and homologous recombination repair gene alterations: second interim analysis of the randomized phase III MAGNITUDE trial.

BACKGROUND: Patients with metastatic castration-resistant prostate cancer (mCRPC) and BRCA alterations have poor outcomes. MAGNITUDE found patients with homologous recombination repair gene alterations (HRR+), particularly BRCA1/2, benefit from first-line therapy with niraparib plus abiraterone acetate and prednisone (AAP). Here we report longer follow-up from the second prespecified interim analysis (IA2). PATIENTS AND METHODS: Patients with mCRPC were prospectively identified as HRR+ with/without BRCA1/2 alterations and randomized 1 : 1 to niraparib (200 mg orally) plus AAP (1000 mg/10 mg orally) or placebo plus AAP. At IA2, secondary endpoints [time to symptomatic progression, time to initiation of cytotoxic chemotherapy, overall survival (OS)] were assessed. RESULTS: Overall, 212 HRR+ patients received niraparib plus AAP (BRCA1/2 subgroup, n = 113). At IA2 with 24.8 months of median follow-up in the BRCA1/2 subgroup, niraparib plus AAP significantly prolonged radiographic progression-free survival {rPFS; blinded independent central review; median rPFS 19.5 versus 10.9 months; hazard ratio (HR) = 0.55 [95% confidence interval (CI) 0.39-0.78]; nominal P = 0.0007} consistent with the first prespecified interim analysis. rPFS was also prolonged in the total HRR+ population [HR = 0.76 (95% CI 0.60-0.97); nominal P = 0.0280; median follow-up 26.8 months]. Improvements in time to symptomatic progression and time to initiation of cytotoxic chemotherapy were observed with niraparib plus AAP. In the BRCA1/2 subgroup, the analysis of OS with niraparib plus AAP demonstrated an HR of 0.88 (95% CI 0.58-1.34; nominal P = 0.5505); the prespecified inverse probability censoring weighting analysis of OS, accounting for imbalances in subsequent use of poly adenosine diphosphate-ribose polymerase inhibitors and other life-prolonging therapies, demonstrated an HR of 0.54 (95% CI 0.33-0.90; nominal P = 0.0181). No new safety signals were observed. CONCLUSIONS: MAGNITUDE, enrolling the largest BRCA1/2 cohort in first-line mCRPC to date, demonstrated improved rPFS and other clinically relevant outcomes with niraparib plus AAP in patients with BRCA1/2-altered mCRPC, emphasizing the importance of identifying this molecular subset of patients.

Clinical outcomes in men of diverse ethnic backgrounds with metastatic castration-resistant prostate cancer.

BACKGROUND: We have shown previously in multivariable analysis that black men had 19% lower risk of death than white men with metastatic castration-resistant prostate cancer (mCRPC) treated with a docetaxel and prednisone (DP)-based regimen. The primary goal of this analysis was to compare progression-free survival (PFS), biochemical PFS, ≥50% decline in prostate-specific antigen (PSA) from baseline and objective response rate (ORR) in white, black and Asian men with mCRPC treated with a DP-based regimen. PATIENTS AND METHODS: Individual patient data from 8820 mCRPC men randomized on nine phase III trials to a DP-containing regimen were combined. Race used in the analysis was based on self-report. End points were PFS, biochemical PSA, ≥50% decline in PSA from baseline and ORR. The proportional hazards and the logistic regression models were employed to assess the prognostic importance of race in predicting outcomes adjusting for established prognostic factors. RESULTS: Of 8820 patients, 7528 (85%) were white, 500 (6%) were black, 424 were Asian (5%) and 368 (4%) had race unspecified. Median PFS were 8.3 [95% confidence interval (CI) 8.2-8.5], 8.2 (95% CI 7.4-8.8) and 8.3 (95% CI 7.6-8.8) months in white, black and Asian men, respectively. Median PSA PFS were 9.9 (95% CI 9.7-10.4), 8.5 (95% CI 8.0-10.3) and 11.1 (95% CI 9.9-12.5) months in white, black and Asian men, respectively. CONCLUSIONS: We observed no differences in clinical outcomes by race and ethnic groups in men with mCRPC enrolled on these phase III clinical trials with DP.

Apalutamide and overall survival in non-metastatic castration-resistant prostate cancer.

BACKGROUND: In the SPARTAN study, compared with placebo, apalutamide added to ongoing androgen deprivation therapy significantly prolonged metastasis-free survival (MFS) and time to symptomatic progression in patients with high-risk non-metastatic castration-resistant prostate cancer (nmCRPC). Overall survival (OS) results at the first interim analysis (IA1) were immature, with 104 of 427 (24%) events required for planned final OS analysis. Here, we report the results of a second pre-specified interim analysis (IA2). METHODS: One thousand two hundred and seven patients with nmCRPC were randomized 2 : 1 to apalutamide (240 mg daily) or placebo. The primary end point of the study was MFS. Subsequent therapy for metastatic CRPC was permitted. When the primary end point was met, the study was unblinded. Patients receiving placebo who had not yet developed metastases were offered open-label apalutamide. At IA2, pre-specified analysis of OS was undertaken, using a group-sequential testing procedure with O'Brien-Fleming-type alpha spending function. Safety and second progression-free survival (PFS2) were assessed. RESULTS: Median follow-up was 41 months. With 285 (67% of required) OS events, apalutamide was associated with an improved OS compared with placebo (HR 0.75; 95% CI 0.59-0.96; P = 0.0197), although the P-value did not cross the pre-specified O'Brien-Fleming boundary of 0.0121. Apalutamide improved PFS2 (HR 0.55; 95% CI 0.45-0.68). At IA2, 69% of placebo-treated and 40% of apalutamide-treated patients had received subsequent life-prolonging therapy for metastatic CRPC. No new safety signals were observed. CONCLUSION: In patients with nmCRPC, apalutamide was associated with a 25% reduction in risk of death compared with placebo. This OS benefit was observed despite crossover of placebo-treated patients and higher rates of subsequent life-prolonging therapy for the placebo group.

Management of patients with advanced prostate cancer: recommendations of the St Gallen Advanced Prostate Cancer Consensus Conference (APCCC) 2015.

The first St Gallen Advanced Prostate Cancer Consensus Conference (APCCC) Expert Panel identified and reviewed the available evidence for the ten most important areas of controversy in advanced prostate cancer (APC) management. The successful registration of several drugs for castration-resistant prostate cancer and the recent studies of chemo-hormonal therapy in men with castration-naïve prostate cancer have led to considerable uncertainty as to the best treatment choices, sequence of treatment options and appropriate patient selection. Management recommendations based on expert opinion, and not based on a critical review of the available evidence, are presented. The various recommendations carried differing degrees of support, as reflected in the wording of the article text and in the detailed voting results recorded in supplementary Material, available at Annals of Oncology online. Detailed decisions on treatment as always will involve consideration of disease extent and location, prior treatments, host factors, patient preferences as well as logistical and economic constraints. Inclusion of men with APC in clinical trials should be encouraged.

A phase II trial of cisplatin (C), gemcitabine (G) and gefitinib for advanced urothelial tract carcinoma: results of Cancer and Leukemia Group B (CALGB) 90102.

BACKGROUND: This phase II trial (Cancer and Leukemia Group B 90102) sought to determine the efficacy of cisplatin, standard infusion of gemcitabine and gefitinib in patients with advanced urothelial carcinoma. PATIENTS AND METHODS: Eligible patients had previously untreated measurable disease, Eastern Cooperative Oncology Group (ECOG) performance status of zero to two and creatinine clearance >50 ml/min. Treatment consisted of cisplatin 70 mg/m(2) day 1 and gemcitabine 1000 mg/m(2) on days 1 and 8 given every 3 weeks concurrent with gefitinib 500 mg/day orally for six cycles. Maintenance gefitinib 500 mg/day was continued for responding or stable disease. RESULTS: Fifty-four of 58 patients were assessable. Twelve patients (22%) had node-only disease, and 25 (46%) had an ECOG performance status of zero. There were 23 objective responses for an overall response rate of 42.6% [95% confidence interval (CI) 29.2% to 56.8%]. The median survival time was 15.1 months (95% CI 11.1-21.7 months) and the median time to progression was 7.4 months (95% CI 5.6-9.2 months). CONCLUSIONS: The combination of cisplatin, gemcitabine and gefitinib is well tolerated and active in advanced transitional cell carcinoma. The addition of gefitinib does not appear to improve response rate or survival in comparison to historical controls of cisplatin and gemcitabine alone.

Phase II study of bortezomib in patients with previously treated advanced urothelial tract transitional cell carcinoma: CALGB 90207.

BACKGROUND: There is no standard second-line treatment for advanced urothelial carcinoma (UC). Response rates to second-line chemotherapy for advanced UC are low and response duration is short. Bortezomib is a proteasome inhibitor with preclinical activity against UC. PATIENTS AND METHODS: Treatment consisted of bortezomib 1.3 mg/m(2) i.v. twice weekly for two consecutive weeks, followed by a 1-week break. The primary end point was objective response rate (complete response + partial response) by Response Evaluation Criteria in Solid Tumors criteria. Secondary end points included safety, toxicity, and progression-free and overall survival. RESULTS: In all, 25 patients with advanced UC previously treated with combination chemotherapy were enrolled in a multi-institutional single-arm trial from December 2003 through April 2005. Only 29% of patients had node-only metastases. Grade 3/4 drug-related toxic effects included thrombocytopenia (4%), anemia (8%), lymphopenia (8%), sensory neuropathy (6%), hyperglycemia (4%), hypernatremia (4%), fatigue (4%), neuropathic pain (6%), dehydration (4%), and vomiting (4%). No objective responses were observed [95% confidence interval (CI) = 0-12]. The median time to progression was 1.4 months (95% CI = 1.1-2.0 months), and the median survival time was 5.7 months (95% CI = 3.6-8.4 months). There were no treatment-related deaths. CONCLUSION: Although bortezomib is well tolerated, it does not have antitumor activity as second-line therapy in UC.

Androgen deprivation therapy in locally advanced and metastatic prostate cancer.

Numerous studies have been performed testing the efficacy of early androgen deprivation (AD) in patients with localized and locally advanced prostate cancer. A systematic review of recent publications that report on the use of AD in non-metastatic prostate cancer patients was performed. Recently published mature randomized trials of AD plus local therapy were evaluated plus 2 large datasets on the use of AD for patients with serologic relapse after local therapy. Four mature randomized studies demonstrate an overall survival benefit to the use of AD in conjunction with definitive local therapy (3 with radiation and 1 with surgery). One retrospective analysis suggests that AD administered at early after serologic progression improves overall survival, and one retrospective analysis shows a reduction in metastasis-free survival but has not yet shown an overall survival benefit. In virtually all analyses, patients with high-risk features benefited from early AD when compared to deferred therapy. Consideration of AD is therefore warranted early in the clinical course of high-risk patients.

Vascular endothelial growth factor and basic fibroblast growth factor urine levels as predictors of outcome in hormone-refractory prostate cancer patients: a cancer and leukemia group B study.

Better prognostic markers are needed for hormone-refractory prostate cancer (HRPC) patients. No single biochemical or clinical parameter can reliably predict patient response to therapy or rapidity of disease progression. Peptide factors involved in major cancer growth pathways, such as tumor angiogenesis, are attractive candidates as markers of low- and high-risk HRPC patients. We analyzed prospectively collected urine specimens from 100 of 390 HRPC patients undergoing therapy with the growth factor antagonist suramin as part of CALGB 9480. Levels of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) were assessed from day 1 of therapy (D1) and day 29 (D29) urine samples from this subset of 100 randomly selected patients. Growth factor levels were determined by standardized ELISA microtiter plate assays from a commercial (bFGF) or proprietary (VEGF) source. Pretreatment urine VEGF levels were predictive of survival. In univariate analysis, patients whose baseline urine VEGF level was < or =28 pg/ml (the median level) had an average survival of 17 months; those with baseline VEGF >28 pg/ml had a significantly shorter survival of 10 months (P = 0.024). This difference corresponded to a 60% increased risk of dying for the higher urine VEGF patients (hazard ratio, 1.62; P = 0.03) and remained significant in multivariate analysis (hazard ratio, 1.72, P = 0.02). No significant correlations between urine bFGF level or change in bFGF levels and survival were found. These results support the notion that certain peptide growth factor-mediated, mitogenic pathways are important in HRPC and that their levels can predict outcome.

Genetic alterations in untreated metastases and androgen-independent prostate cancer detected by comparative genomic hybridization and allelotyping.

A newly developed method of comparative genomic hybridization (CGH) employing quantitative statistical comparisons was applied to DNA from two different types of advanced prostate cancer tissue. Multiple CGH analyses were obtained for each chromosome in each tumor, and the results of point-by-point comparison of the mean tumor:normal color ratio to a control normal:normal color ratio in each of 1247 evenly distributed data channels constituting the entire human genome were interpreted as loss, gain, or no change in copy number in the tumor genome. Group I tissue was obtained from prostate cancer metastases from 20 patients, 19 of whom had received no prior prostate cancer treatment. This DNA also was analyzed by Southern and microsatellite allelotyping at 53 different loci on 20 different chromosome arms. CGH results agreed with allelotyping results at 92% of the informative loci studied. These samples, which contained highly enriched tumor DNA, showed the highest rates of alteration yet reported in several chromosomal regions known to be altered frequently in prostate cancer: 8q gain (85%), 8p loss (80%), 13q loss (75%), 16q loss (55%), 17p loss (50%), and 10q loss (50%). Group II tissue was obtained predominately from primary or recurrent tumor from 11 patients who had been treated with long-term androgen-deprivation therapy and developed androgen-independent metastatic disease. Quantitative CGH analysis on DNA from these tissues showed chromosomal alterations that were very similar to those found in group I, suggesting that untreated metastatic tumors contain the bulk of chromosomal alterations necessary for recurrence to occur during androgen deprivation. In the entire data set, a number of previously undetected regions of frequent loss or gain were identified, including losses of chromosomes 2q (42%), 5q (39%), 6q (39%), and 15q (39%) and gains of chromosomes 11p (52%), 1q (52%), 3q (52%), and 2p (45%). Chi-squared analysis showed a significantly higher frequency of gain of the 4q25-q28 region in tumors from African-American patients, indicating a possible oncogene whose activation may play a role in the higher rate of progression seen in this ethnic group. Additional study of these frequently altered regions may provide insight into the mechanism of prostate cancer progression and lead to important tools for tumor-specific prognosis and therapy.

Selection for androgen receptor mutations in prostate cancers treated with androgen antagonist.

The role of androgen receptor (AR) mutations in androgen-independent prostate cancer (PCa) was determined by examining AR transcripts and genes from a large series of bone marrow metastases. Mutations were found in 5 of 16 patients who received combined androgen blockade with the AR antagonist flutamide, and these mutant ARs were strongly stimulated by flutamide. In contrast, the single mutant AR found among 17 patients treated with androgen ablation monotherapy was not flutamide stimulated. Patients with flutamide-stimulated AR mutations responded to subsequent treatment with bicalutamide, an AR antagonist that blocks the mutant ARs. These findings demonstrate that AR mutations occur in response to strong selective pressure from flutamide treatment.

Second-line hormonal therapy for advanced prostate cancer: a shifting paradigm.

PURPOSE: To discuss the evolution of new concepts in the Use of second-line hormonal therapy for patients with progressive prostate cancer despite androgen deprivation. DESIGN: Pertinent contemporary prostate-specific antigen (PSA)-based reports of the utility of secondary hormonal maneuvers after treatment with combined androgen blockade (CAB) were reviewed. RESULTS: The use of PSA as an end point in hormonerefractory prostate cancer (HRPC) trials is more widely accepted, but still remains somewhat controversial. Using PSA as an end point, it is clear that a variety of secondary hormonal maneuvers can result in responses. Antiandrogen withdrawal is efficacious in approximately 20% of patients and can be observed with a variety of antiandrogens, including flutamide, bicalutamide, and megestrol acetate. A variety of regimens, including megestrol, bicalutamide, glucocorticoids, aminoglutethimide, and ketoconazole, retain activity (14% to 75% PSA response proportion) even in patients who have failed to respond to CAB and flutamide withdrawal. CONCLUSION: Once CAB (suppression of gonadal and adrenal androgen) is undertaken, further hormonal maneuvers remain efficacious in some patients with progressive prostate cancer. Antiandrogen withdrawal is now a mandatory maneuver before proceeding to other regimens. It is clear that certain patients will continue to respond to hormonal maneuvers even after antiandrogen withdrawal. An understanding of the molecular basis of these responses may result in the development of a more targeted therapy in the future.

Malignant germ cell tumors in men infected with the human immunodeficiency virus: natural history and results of therapy.

PURPOSE: To determine how men infected with the human immunodeficiency virus (HIV) tolerate and respond to treatment for malignant germ cell tumors (GCTs), and how GCT histology and stage compare among HIV-infected versus non-HIV-infected men. PATIENTS AND METHODS: Two hundred ninety-four cases of GCT diagnosed or treated from 1980 to 1993 were reviewed. Nine new cases among HIV-infected men were identified; these were analyzed together with six cases previously reported from our institution. RESULTS: Low-stage tumors (stages I and IIA) comprised 67% of HIV-infected and 63% of non-HIV-infected cases. Sixty-seven percent of HIV-infected cases were seminomas versus 51% of non-HIV-infected cases. Ten patients had AIDS at the time of GCT diagnosis. Five patients underwent radiation therapy and one patient underwent retroperitoneal lymphadenectomy without complications. Seven patients received chemotherapy with four cycles of cisplatin, etoposide, and bleomycin (PEB) or cisplatin, vinblastine, and bleomycin (PVB) without excess cytopenias or new opportunistic infections. Of seven patients treated for advanced disease, there were five complete and two partial responses. Six patients have died of AIDS at a median of 20 months after diagnosis of GCT. The median follow-up time for surviving patients has been 42 months (range, 8 to 87) and all but one remain without evidence of active disease. In no case was a patient's HIV disease classification altered by antitumor therapy. CONCLUSION: The natural history of GCTs is comparable in HIV-infected and non-HIV-infected men and standard therapy including orchiectomy, retroperitoneal lymph node dissection, radiation therapy, and chemotherapy is well tolerated.

Doxorubicin and dose-escalated cyclophosphamide with granulocyte colony-stimulating factor for the treatment of hormone-resistant prostate cancer.

PURPOSE: The goals of this study were to define the efficacy and toxicity of doxorubicin and dose-escalated cyclophosphamide (Cy) along with granulocyte colony-stimulating factor (G-CSF) in the treatment of hormone-refractory prostate cancer (HRPC), to determine the maximal-tolerated dose (MTD) of Cy in this regimen, and to evaluate the impact of prior pelvic irradiation (XRT) on MTD and toxicity. PATIENTS AND METHODS: Thirty-five patients were treated every 21 days with fixed-dose doxorubicin (40 mg/m2) and Cy 800 to 2,000 mg/m2 (in a cohort dose-escalation schema) along with G-CSF. RESULTS: Five of 15 patients (33%) with measurable disease obtained an objective response. Sixteen of 35 patients (46%) had a greater than 50% decrease in prostate-specific antigen (PSA) level (95% confidence interval [CI], 28.8% to 63.4%). Ten of 35 patients (28.6%) had a greater than 75% decrease in PSA level. The median survival time was 11 months. The median survival duration of patients with a greater than 50% decrease in PSA level was 23 months, versus a median survival time of 7 months in patients without a PSA response (P = .02). Although 33% of cycles were associated with grade 4 neutropenia, febrile neutropenia occurred in only 7.8% of all cycles. Thrombocytopenia and anemia were rare. Nonhematologic toxicity was minimal. Patients who had received prior pelvic XRT had a lower Cy MTD, but their hematologic toxicity was not appreciably different. CONCLUSION: This is a well-tolerated, active regimen for the treatment of HRPC. Toxicity was not different in patients with prior pelvic XRT, although these patients had a lower MTD.

Serum prostate-specific antigen decline as a marker of clinical outcome in hormone-refractory prostate cancer patients: association with progression-free survival, pain end points, and survival.

PURPOSE: Validated end points are lacking for clinical trials in hormone-refractory prostate cancer (HRPC). Controversy remains regarding the utility of a posttreatment decline of prostate-specific antigen (PSA). The purpose of this study was to determine whether posttreatment declines in PSA were associated with clinical measures of improvement in a randomized phase III trial of suramin plus hydrocortisone versus placebo plus hydrocortisone. PATIENTS AND METHODS: A total of 460 HRPC patients were randomized to receive suramin plus hydrocortisone (n = 229) or placebo plus hydrocortisone (n = 231). All patients had symptomatic, metastatic HRPC requiring opioid analgesics. Clinical end points evaluated included overall survival, objective progression-free survival (OPFS), and time to pain progression (TTPP). An evaluation of overall survival, OPFS, and TTPP as a function of a PSA decline of > or = 50%, lasting at least 28 days, was undertaken by using a landmark analysis at 6, 9, and 12 weeks. A multivariate analysis of the impact of PSA decline was performed on these clinical end points. RESULTS: A decline in PSA of > or = 50% lasting > or = 28 days was significantly associated with a prolonged median overall survival, OPFS, and TTPP, both in the entire group and the suramin plus hydrocortisone group at all three landmarks in both univariate and multivariate analysis. CONCLUSION: In this prospective, randomized trial of suramin plus hydrocortisone versus placebo plus hydrocortisone, a posttherapy decline in PSA of > or = 50%, lasting 28 days, was associated with prolonged median overall survival, improved median progression-free survival, and median TTPP. This analysis suggests that a posttreatment decline in PSA may be a reasonable intermediate end point in HRPC trials and calls into question the clinical utility of preclinical assays evaluating the in vitro effect of given agents on PSA secretion.

Prognostic significance of reverse transcriptase polymerase chain reaction for prostate-specific antigen in men with hormone-refractory prostate cancer.

PURPOSE: To evaluate the prognostic significance of reverse transcriptase polymerase chain reaction (RT-PCR) detection of prostate-specific antigen (PSA) mRNA in the blood of men with hormone-refractory prostate cancer (HRPC). PATIENTS AND METHODS: Peripheral blood was obtained from 193 men enrolled on Cancer and Leukemia Group B Study 9480, a prospective randomized comparison of three doses of suramin. RNA was isolated from the samples and assayed for the presence of PSA transcripts by RT-PCR. RESULTS: RNA could be isolated in 156 (83%) of samples. PSA transcripts as measured by RT-PCR were detectable in 75 (48%) of the 156 patients. The median survival for those patients in whom no transcripts were detectable was 18 months (95% confidence interval [CI], 14 to 22 months) compared with 13 months (95% CI, 11 to 15 months) (P =.004) for those in whom transcripts were detectable. In a multivariate analysis in which other factors predictive of survival were used, RT-PCR for PSA provided independent prognostic information. CONCLUSION: RT-PCR for PSA predicts survival duration in a population of men with HRPC.

Immunotherapy of hormone-refractory prostate cancer with antigen-loaded dendritic cells.

PURPOSE: Provenge (Dendreon Corp, Seattle, WA) is an immunotherapy product consisting of autologous dendritic cells loaded ex vivo with a recombinant fusion protein consisting of prostatic acid phosphatase (PAP) linked to granulocyte-macrophage colony-stimulating factor. Sequential phase I and phase II trials were performed to determine the safety and efficacy of Provenge and to assess its capacity to break immune tolerance to the normal tissue antigen PAP. PATIENTS AND METHODS: All patients had hormone-refractory prostate cancer. Dendritic-cell precursors were harvested by leukapheresis in weeks 0, 4, 8, and 24, loaded ex vivo with antigen for 2 days, and then infused intravenously over 30 minutes. Phase I patients received increasing doses of Provenge, and phase II patients received all the Provenge that could be prepared from a leukapheresis product. RESULTS: Patients tolerated treatment well. Fever, the most common adverse event, occurred after 15 infusions (14.7%). All patients developed immune responses to the recombinant fusion protein used to prepare Provenge, and 38% developed immune responses to PAP. Three patients had a more than 50% decline in prostate-specific antigen (PSA) level, and another three patients had 25% to 49% decreases in PSA. The time to disease progression correlated with development of an immune response to PAP and with the dose of dendritic cells received. CONCLUSION: Provenge is a novel immunotherapy agent that is safe and breaks tolerance to the tissue antigen PAP. Preliminary evidence for clinical efficacy warrants further exploration.

Phase II study of docetaxel, estramustine, and low-dose hydrocortisone in men with hormone-refractory prostate cancer: a final report of CALGB 9780. Cancer and Leukemia Group B.

PURPOSE: To investigate the combination of docetaxel, estramustine (EM), and low-dose hydrocortisone in men with hormone-refractory prostate cancer (HRPC). PATIENTS AND METHODS: Combinations of EM with other antimitotic agents such as docetaxel are synergistic in vitro and show significant clinical activity in patients with HRPC. We studied intravenous administration of docetaxel 70 mg/m(2), oral estramustine, and low-dose daily hydrocortisone in men with HRPC who demonstrated progression after initial hormone therapy. RESULTS: Of the 47 men enrolled onto this multicenter cooperative group study, 46 were assessable for response and/or toxicity. In the 24 patients with measurable disease, there were three complete and nine partial responses for a measurable disease response rate of 50% (12 of 24 patients; 95% confidence interval [CI], 27% to 73%). In the 44 patients in whom pretreatment prostate-specific antigen (PSA) was elevated, 30 (68%) had a 50% or greater decrease, and 25 (57%) had a 75% or greater decrease in PSA. The combined measurable disease and biochemical response rate in all 46 assessable patients was 54% (three complete responses, 22 partial responses, 95% CI, 37% to 71%). The predominant toxicity was neutropenia, with 26% of patients having grade 3 and 30% having grade 4 granulocytopenia; there were no episodes of febrile neutropenia. Other common but mild adverse effects included malaise/fatigue, peripheral edema, and hyperglycemia. The incidence of thromboembolic events during therapy was 9%. With a median follow-up of 17 months, the median survival was 20 months. The median time to disease progression was 8 months for all patients, and 10 months for those with measurable disease. CONCLUSION: This therapy is efficacious and moderately well tolerated in HRPC and should be compared in a phase III trial with mitoxantrone and prednisone.