Thomas W. Flaig

Abiraterone and Increased Survival in Metastatic Prostate Cancer

BACKGROUND Biosynthesis of extragonadal androgen may contribute to the progression of castration-resistant prostate cancer. We evaluated whether abiraterone acetate, an inhibitor of androgen biosynthesis, prolongs overall survival among patients with metastatic castration-resistant prostate cancer who have received chemotherapy. METHODS We randomly assigned, in a 2:1 ratio, 1195 patients who had previously received docetaxel to receive 5 mg of prednisone twice daily with either 1000 mg of abiraterone acetate (797 patients) or placebo (398 patients). The primary end point was overall survival. The secondary end points included time to prostate-specific antigen (PSA) progression (elevation in the PSA level according to prespecified criteria), progression-free survival according to radiologic findings based on prespecified criteria, and the PSA response rate. RESULTS After a median follow-up of 12.8 months, overall survival was longer in the abiraterone acetate-prednisone group than in the placebo-prednisone group (14.8 months vs. 10.9 months; hazard ratio, 0.65; 95% confidence interval, 0.54 to 0.77; P<0.001). Data were unblinded at the interim analysis, since these results exceeded the preplanned criteria for study termination. All secondary end points, including time to PSA progression (10.2 vs. 6.6 months; P<0.001), progression-free survival (5.6 months vs. 3.6 months; P<0.001), and PSA response rate (29% vs. 6%, P<0.001), favored the treatment group. Mineralocorticoid-related adverse events, including fluid retention, hypertension, and hypokalemia, were more frequently reported in the abiraterone acetate-prednisone group than in the placebo-prednisone group. CONCLUSIONS The inhibition of androgen biosynthesis by abiraterone acetate prolonged overall survival among patients with metastatic castration-resistant prostate cancer who previously received chemotherapy. (Funded by Cougar Biotechnology; COU-AA-301 ClinicalTrials.gov number, NCT00638690.).

Abiraterone in Metastatic Prostate Cancer without Previous Chemotherapy

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; ClinicalTrials.gov number, NCT00887198.).

Abiraterone acetate plus prednisone versus placebo plus prednisone in chemotherapy-naive men with metastatic castration-resistant prostate cancer (COU-AA-302): final overall survival analysis of a randomised, double-blind, placebo-controlled phase 3 study

BACKGROUND Abiraterone acetate plus prednisone significantly improved radiographic progression-free survival compared with placebo plus prednisone in men with chemotherapy-naive castration-resistant prostate cancer at the interim analyses of the COU-AA-302 trial. Here, we present the prespecified final analysis of the trial, assessing the effect of abiraterone acetate plus prednisone on overall survival, time to opiate use, and use of other subsequent therapies. METHODS In this placebo-controlled, double-blind, randomised phase 3 study, 1088 asymptomatic or mildly symptomatic patients with chemotherapy-naive prostate cancer stratified by Eastern Cooperative Oncology performance status (0 vs 1) were randomly assigned with a permuted block allocation scheme via a web response system in a 1:1 ratio to receive either abiraterone acetate (1000 mg once daily) plus prednisone (5 mg twice daily; abiraterone acetate group) or placebo plus prednisone (placebo group). Coprimary endpoints were radiographic progression-free survival and overall survival analysed in the intention-to-treat population. The study is registered with ClinicalTrials.gov, number NCT00887198. FINDINGS At a median follow-up of 49.2 months (IQR 47.0-51.8), 741 (96%) of the prespecified 773 death events for the final analysis had been observed: 354 (65%) of 546 patients in the abiraterone acetate group and 387 (71%) of 542 in the placebo group. 238 (44%) patients initially receiving prednisone alone subsequently received abiraterone acetate plus prednisone as crossover per protocol (93 patients) or as subsequent therapy (145 patients). Overall, 365 (67%) patients in the abiraterone acetate group and 435 (80%) in the placebo group received subsequent treatment with one or more approved agents. Median overall survival was significantly longer in the abiraterone acetate group than in the placebo group (34.7 months [95% CI 32.7-36.8] vs 30.3 months [28.7-33.3]; hazard ratio 0.81 [95% CI 0.70-0.93]; p=0.0033). The most common grade 3-4 adverse events of special interest were cardiac disorders (41 [8%] of 542 patients in the abiraterone acetate group vs 20 [4%] of 540 patients in the placebo group), increased alanine aminotransferase (32 [6%] vs four [<1%]), and hypertension (25 [5%] vs 17 [3%]). INTERPRETATION In this randomised phase 3 trial with a median follow-up of more than 4 years, treatment with abiraterone acetate prolonged overall survival compared with prednisone alone by a margin that was both clinically and statistically significant. These results further support the favourable safety profile of abiraterone acetate in patients with chemotherapy-naive metastatic castration-resistant prostate cancer. FUNDING Janssen Research & Development.

Phase II Randomized Trial Comparing Sequential First-Line Everolimus and Second-Line Sunitinib Versus First-Line Sunitinib and Second-Line Everolimus in Patients With Metastatic Renal Cell Carcinoma

PURPOSE A multicenter, randomized phase II trial, RECORD-3, was conducted to compare first-line everolimus followed by sunitinib at progression with the standard sequence of first-line sunitinib followed by everolimus in patients with metastatic renal cell carcinoma. PATIENTS AND METHODS RECORD-3 used a crossover treatment design. The primary objective was to assess progression-free survival (PFS) noninferiority of first-line everolimus compared with first-line sunitinib. Secondary end points included combined PFS for each sequence, overall survival (OS), and safety. RESULTS Of 471 enrolled patients, 238 were randomly assigned to first-line everolimus followed by sunitinib, and 233 were randomly assigned to first-line sunitinib followed by everolimus. The primary end point was not met; the median PFS was 7.9 months for first-line everolimus and 10.7 months for first-line sunitinib (hazard ratio [HR], 1.4; 95% CI, 1.2 to 1.8). Among patients who discontinued first-line, 108 (45%) crossed over from everolimus to second-line sunitinib, and 99 (43%) crossed over from sunitinib to second-line everolimus. The median combined PFS was 21.1 months for sequential everolimus then sunitinib and was 25.8 months for sequential sunitinib then everolimus (HR, 1.3; 95% CI, 0.9 to 1.7). The median OS was 22.4 months for sequential everolimus and then sunitinib and 32.0 months for sequential sunitinib and then everolimus (HR, 1.2; 95% CI, 0.9 to 1.6). Common treatment-emergent adverse events during first-line everolimus or sunitinib were stomatitis (53% and 57%, respectively), fatigue (45% and 51%, respectively), and diarrhea (38% and 57%, respectively). CONCLUSION Everolimus did not demonstrate noninferiority compared with sunitinib as a first-line therapy. The trial results support the standard treatment paradigm of first-line sunitinib followed by everolimus at progression.

Expert consensus document

Multiple clinical trials have demonstrated that intravesical Bacillus Calmette–Guérin (BCG) treatment reduces recurrences and progression in patients with non-muscle-invasive bladder cancer (NMIBC). However, although BCG has been in use for almost 40 years, this agent is often underutilized and practice patterns of administration vary. This neglect is most likely caused by uncertainties about the optimal use of BCG, including unawareness of optimal treatment schedules and about patient populations that most benefit from BCG treatment. To address this deficit, a focus group of specialized urologic oncologists (urologists, medical oncologists and radiation oncologists) reviewed the current guidelines and clinical evidence, discussed their experiences and formed a consensus regarding the optimal use of BCG in the management of patients with NIMBC. The experts concluded that continuing therapy with 3-week BCG maintenance is superior to induction treatment only and is the single most important factor in improving outcomes in patients with NMIBC. They also concluded that a reliable alternative to radical cystectomy in truly BCG-refractory disease remains the subject of clinical trials. In addition, definitions for common terms of BCG failure, such as BCG-refractory and BCG-intolerant, have been formulated.

Stereotactic body radiation therapy for melanoma and renal cell carcinoma: impact of single fraction equivalent dose on local control

BackgroundMelanoma and renal cell carcinoma (RCC) are traditionally considered less radioresponsive than other histologies. Whereas stereotactic body radiation therapy (SBRT) involves radiation dose intensification via escalation, we hypothesize SBRT might result in similar high local control rates as previously published on metastases of varying histologies.MethodsThe records of patients with metastatic melanoma (n = 17 patients, 28 lesions) or RCC (n = 13 patients, 25 lesions) treated with SBRT were reviewed. Local control (LC) was defined pathologically by negative biopsy or radiographically by lack of tumor enlargement on CT or stable/declining standardized uptake value (SUV) on PET scan. The SBRT dose regimen was converted to the single fraction equivalent dose (SFED) to characterize the dose-control relationship using a logistic tumor control probability (TCP) model. Additionally, the kinetics of decline in maximum SUV (SUVmax) were analyzed.ResultsThe SBRT regimen was 40-50 Gy/5 fractions (n = 23) or 42-60 Gy/3 fractions (n = 30) delivered to lung (n = 39), liver (n = 11) and bone (n = 3) metastases. Median follow-up for patients alive at the time of analysis was 28.0 months (range, 4-68). The actuarial LC was 88% at 18 months. On univariate analysis, higher dose per fraction (p < 0.01) and higher SFED (p = 0.06) were correlated with better LC, as was the biologic effective dose (BED, p < 0.05). The actuarial rate of LC at 24 months was 100% for SFED ≥45 Gy v 54% for SFED <45 Gy. TCP modeling indicated that to achieve ≥90% 2 yr LC in a 3 fraction regimen, a prescription dose of at least 48 Gy is required. In 9 patients followed with PET scans, the mean pre-SBRT SUVmax was 7.9 and declined with an estimated half-life of 3.8 months to a post-treatment plateau of approximately 3.ConclusionsAn aggressive SBRT regimen with SFED ≥ 45 Gy is effective for controlling metastatic melanoma and RCC. The SFED metric appeared to be as robust as the BED in characterizing dose-response, though additional studies are needed. The LC rates achieved are comparable to those obtained with SBRT for other histologies, suggesting a dominant mechanism of in vivo tumor ablation that overrides intrinsic differences in cellular radiosensitivity between histologic subtypes.

A study of high‐dose oral silybin‐phytosome followed by prostatectomy in patients with localized prostate cancer

Silibinin is a polyphenolic flavonolignan derived from milk thistle (Silybum marianium) with anti‐oxidant properties. The purpose of the current trial was to determine the tissue and blood effects of high‐dose silybin‐phytosome in prostate cancer patients.

Adjuvant Androgen Deprivation for High-Risk Prostate Cancer After Radical Prostatectomy: SWOG S9921 Study

PURPOSE Men with high-risk features (extraprostatic extension or high Gleason grade) face a high risk of prostate cancer recurrence after radical prostatectomy. Clinical trials of adjuvant systemic therapy for such patients have been limited. PATIENTS AND METHODS The SWOG (Southwest Oncology Group) S9921 study randomly assigned 983 men with high-risk features at prostatectomy to receive adjuvant therapy with androgen deprivation (ADT) alone or in combination with mitoxantrone chemotherapy. ADT consisted of goserelin and bicalutamide for 2 years. RESULTS Although the final primary treatment comparison results are not ready for publication, this article reports results in the ADT-alone control arm with a median follow-up of 4.4 years. For these 481 men, the estimated 5-year biochemical failure-free survival is 92.5% (95% CI, 90 to 95), and 5-year overall survival is 95.9% (95% CI, 93.9 to 97.9). CONCLUSION The results of this trial, taken in context, make a compelling argument for counseling all high-risk patients with prostate cancer about adjuvant ADT. This article discusses the challenges in the design and implementation of clinical trials to take the next step forward in adjuvant therapy for prostate cancer because of the excellent survival achieved with currently available therapies and highlights the need for better molecular markers to personalize care.

Improved Survival With Prostate Radiation in Addition to Androgen Deprivation Therapy for Men With Newly Diagnosed Metastatic Prostate Cancer

PURPOSE There is growing interest in the role of local therapies, including external beam radiotherapy (RT), for men with metastatic prostate cancer (mPCa). We used the National Cancer Database (NCDB) to evaluate the overall survival (OS) of men with mPCa treated with androgen deprivation (ADT) with and without prostate RT. METHODS The NCDB was queried for men with newly diagnosed mPCa, all treated with ADT, with complete datasets for RT, surgery, prostate-specific antigen (PSA) level, Gleason score, and Charlson-Deyo comorbidity score. OS was analyzed using the Kaplan-Meier method, log-rank test, Cox proportional hazards models, and propensity score-matched analyses. RESULTS From 2004 to 2012, 6,382 men with mPCa were identified, including 538 (8.4%) receiving prostate RT. At a median follow-up of 5.1 years, the addition of prostate RT to ADT was associated with improved OS on univariate (P < .001) and multivariate analysis (hazard ratio, 0.624; 95% CI, 0.551 to 0.706; P < .001) adjusted for age, year, race, comorbidity score, PSA level, Gleason score, T stage, N stage, chemotherapy administration, treating facility, and insurance status. Propensity score analysis with matched baseline characteristics demonstrated superior median (55 v 37 months) and 5-year OS (49% v 33%) with prostate RT plus ADT compared with ADT alone (P < .001). Landmark analyses limited to long-term survivors of ≥1, ≥3, and ≥5 years demonstrated improved OS with prostate RT in all subsets (all P < .05). Secondary analyses comparing the survival outcomes for patients treated with therapeutic dose RT plus ADT versus prostatectomy plus ADT during the same time interval demonstrated no significant differences in OS, whereas both therapies were superior to ADT alone. CONCLUSION In this large contemporary analysis, men with mPCa receiving prostate RT and ADT lived substantially longer than men treated with ADT alone. Prospective trials evaluating local therapies for mPCa are warranted.

Randomization Reveals Unexpected Acute Leukemias in Southwest Oncology Group Prostate Cancer Trial

PURPOSE Southwest Oncology Group (SWOG) study 9921 is a randomized, phase III, intergroup study to define the role of adjuvant chemotherapy in patients with high-risk prostate cancer. PATIENTS AND METHODS We allocated 983 patients with prostate cancer with high-risk features to receive 2 years of androgen-deprivation therapy (ADT) with or without six cycles of mitoxantrone (12 mg/m(2)) after prostatectomy. RESULTS In January 2007, SWOG 9921 was closed to further accrual after three cases of acute myelogenous leukemia (AML) were reported of a total of 487 patients in the mitoxantrone treatment arm. The key cytogenetic features of these cases included inv(16) in the first case, t(15;17) in the second, and del(5) in the third case. Time from the start of mitoxantrone to the detection of AML was 13, 48, and 72 months, respectively. Before SWOG 9921, there were no cases of mitoxantrone-induced AML reported in patients treated for prostate cancer. CONCLUSION The emergence of this possible pattern of secondary malignancy emphasizes the importance of randomized controlled trials in defining safety and efficacy of new approaches for patients in the adjuvant setting.