Apalutamide Treatment and Metastasis-free Survival in Prostate Cancer.

BACKGROUND: Apalutamide, a competitive inhibitor of the androgen receptor, is under development for the treatment of prostate cancer. We evaluated the efficacy of apalutamide in men with nonmetastatic castration-resistant prostate cancer who were at high risk for the development of metastasis. METHODS: We conducted a double-blind, placebo-controlled, phase 3 trial involving men with nonmetastatic castration-resistant prostate cancer and a prostate-specific antigen doubling time of 10 months or less. Patients were randomly assigned, in a 2:1 ratio, to receive apalutamide (240 mg per day) or placebo. All the patients continued to receive androgen-deprivation therapy. The primary end point was metastasis-free survival, which was defined as the time from randomization to the first detection of distant metastasis on imaging or death. RESULTS: A total of 1207 men underwent randomization (806 to the apalutamide group and 401 to the placebo group). In the planned primary analysis, which was performed after 378 events had occurred, median metastasis-free survival was 40.5 months in the apalutamide group as compared with 16.2 months in the placebo group (hazard ratio for metastasis or death, 0.28; 95% confidence interval [CI], 0.23 to 0.35; P<0.001). Time to symptomatic progression was significantly longer with apalutamide than with placebo (hazard ratio, 0.45; 95% CI, 0.32 to 0.63; P<0.001). The rate of adverse events leading to discontinuation of the trial regimen was 10.6% in the apalutamide group and 7.0% in the placebo group. The following adverse events occurred at a higher rate with apalutamide than with placebo: rash (23.8% vs. 5.5%), hypothyroidism (8.1% vs. 2.0%), and fracture (11.7% vs. 6.5%). CONCLUSIONS: Among men with nonmetastatic castration-resistant prostate cancer, metastasis-free survival and time to symptomatic progression were significantly longer with apalutamide than with placebo. (Funded by Janssen Research and Development; SPARTAN ClinicalTrials.gov number, NCT01946204 .).

Hepatic safety analysis of trabectedin: results of a pharmacokinetic study with trabectedin in patients with hepatic impairment and experience from a phase 3 clinical trial.

Purpose Trabectedin is metabolized by the liver and has been associated with transient, noncumulative transaminase elevation. Two recent studies further characterize hepatic tolerability with trabectedin therapy: a phase 1 pharmacokinetic study (Study #1004; NCT01273493) in patients with advanced malignancies and hepatic impairment (HI), and a phase 3 study (Study #3007; NCT01343277) of trabectedin vs. dacarbazine in patients with advanced sarcomas and normal hepatic function. Methods In Study #1004, patients received a single 3-h intravenous (IV) infusion of trabectedin: control group, trabectedin 1.3 mg/m2; HI group (baseline total bilirubin >1.5 and ≤3× upper limit of normal [ULN]; AST and ALT ≤2.5× ULN), trabectedin 0.58 or 0.9 mg/m2. In Study #3007, the trabectedin group received 1.5 mg/m2 by 24-h IV infusion every 3 weeks until disease progression or unacceptable toxicity. Results In Study #1004, dose-normalized trabectedin exposure was higher in HI patients (n = 6) versus controls (n = 9) (geometric mean ratios [90% CI] AUClast: 1.97 [1.20; 3.22]). In Study #3007, following trabectedin administration, 90% of patients had elevated ALT (32% grade 3-4) and 84% had elevated AST (17% grade 3-4). Transaminase elevations were transient and noncumulative. Progression-free survival was similar in patients with grade 3-4 hepatotoxicity (n = 109) versus grade 0-2 hepatotoxicity (n = 231) (median [95% CI]: 4.63 [4.01, 5.85] months versus 3.55 [2.73, 4.63] months; P = 0.545, HR = 0.91 [0.68-1.23]). Conclusion Trabectedin treatment of patients with HI results in higher plasma exposures. Hepatotoxicity in patients with normal liver function can be effectively addressed through dose reductions and delays.

Abiraterone plus Prednisone in Metastatic, Castration-Sensitive Prostate Cancer.

BACKGROUND: Abiraterone acetate, a drug that blocks endogenous androgen synthesis, plus prednisone is indicated for metastatic castration-resistant prostate cancer. We evaluated the clinical benefit of abiraterone acetate plus prednisone with androgen-deprivation therapy in patients with newly diagnosed, metastatic, castration-sensitive prostate cancer. METHODS: In this double-blind, placebo-controlled, phase 3 trial, we randomly assigned 1199 patients to receive either androgen-deprivation therapy plus abiraterone acetate (1000 mg daily, given once daily as four 250-mg tablets) plus prednisone (5 mg daily) (the abiraterone group) or androgen-deprivation therapy plus dual placebos (the placebo group). The two primary end points were overall survival and radiographic progression-free survival. RESULTS: After a median follow-up of 30.4 months at a planned interim analysis (after 406 patients had died), the median overall survival was significantly longer in the abiraterone group than in the placebo group (not reached vs. 34.7 months) (hazard ratio for death, 0.62; 95% confidence interval [CI], 0.51 to 0.76; P<0.001). The median length of radiographic progression-free survival was 33.0 months in the abiraterone group and 14.8 months in the placebo group (hazard ratio for disease progression or death, 0.47; 95% CI, 0.39 to 0.55; P<0.001). Significantly better outcomes in all secondary end points were observed in the abiraterone group, including the time until pain progression, next subsequent therapy for prostate cancer, initiation of chemotherapy, and prostate-specific antigen progression (P<0.001 for all comparisons), along with next symptomatic skeletal events (P=0.009). These findings led to the unanimous recommendation by the independent data and safety monitoring committee that the trial be unblinded and crossover be allowed for patients in the placebo group to receive abiraterone. Rates of grade 3 hypertension and hypokalemia were higher in the abiraterone group. CONCLUSIONS: The addition of abiraterone acetate and prednisone to androgen-deprivation therapy significantly increased overall survival and radiographic progression-free survival in men with newly diagnosed, metastatic, castration-sensitive prostate cancer. (Funded by Janssen Research and Development; LATITUDE ClinicalTrials.gov number, NCT01715285 .).

Modeling the Relationship Between Exposure to Abiraterone and Prostate-Specific Antigen Dynamics in Patients with Metastatic Castration-Resistant Prostate Cancer.

BACKGROUND AND OBJECTIVES: Recent analysis revealed strong associations between prostate-specific antigen (PSA) dynamics and overall survival (OS) in metastatic castration-resistant prostate cancer (mCRPC) and supported PSA dynamics as bridging surrogacy endpoints for clinical benefit from treatment with abiraterone acetate plus prednisone. This analysis aimed to investigate the abiraterone exposure-PSA dynamics relationship in mCRPC. METHODS: Abiraterone pharmacokinetics-PSA models were constructed using data from the COU-AA-301 (chemotherapy-pretreated) and COU-AA-302 (chemotherapy-naïve) trials comparing abiraterone acetate 1000 mg/day plus prednisone 5 mg twice daily with prednisone alone in mCRPC. The drug effect-PSA dynamics relationship was modeled as a function of selected pharmacokinetic measures. The influences of baseline demographic variables, laboratory values, and disease status on PSA dynamics were assessed. RESULTS: A tumor growth inhibition model best described PSA dynamics post-treatment with abiraterone acetate. Abiraterone acetate treatment in chemotherapy-pretreated and chemotherapy-naïve patients increased the PSA decay rate (k dec) to the same extent (1.28-fold, 95 % confidence interval [CI] 0.58-1.98; and 0.93-fold, 95 % CI 0.6-1.27, respectively). Lower baseline lactate dehydrogenase and higher baseline testosterone significantly increased k dec. Findings from our analysis suggest a maximum-effect relationship between abiraterone trough concentration and PSA dynamics in both patient populations. The majority of patients had a steady-state trough concentration greater than the estimated half maximal effective concentration. CONCLUSION: The model appropriately described the exposure-response relationship between abiraterone and PSA dynamics in chemotherapy-pretreated and chemotherapy-naïve patients following oral administration of abiraterone acetate.

Correlation between Prostate-Specific Antigen Kinetics and Overall Survival in Abiraterone Acetate-Treated Castration-Resistant Prostate Cancer Patients.

PURPOSE: We constructed a biomarker-survival modeling framework to explore the relationship between prostate-specific antigen (PSA) kinetics and overall survival (OS) in metastatic castration-resistant prostate cancer (mCRPC) patients following oral administration of 1,000 mg/day of abiraterone acetate (AA). EXPERIMENTAL DESIGN: The PSA-survival modeling framework was based on data from two phase III studies, COU-AA-301 (chemotherapy pretreated, n = 1,184) and COU-AA-302 (chemotherapy naïve, n = 1,081), and included a mixed-effects tumor growth inhibition model and a Cox proportional hazards survival model. RESULTS: The effect of AA on PSA kinetics was significant (P < 0.0001) and comparable between the chemotherapy-naïve and -pretreated patients. PSA kinetics [e.g., PSA nadir, PSA response rate (≥30%, 50%, and 90%), time to PSA progression, PSA doubling time (PSADT)] were highly associated with OS in both populations. The model-based posttreatment PSADT had the strongest association with OS (HR ∼0.9 in both populations). The models could accurately predict survival outcomes. After adjusting for PSA kinetic endpoints, the treatment effect of AA on survival was no longer statistically significant in both studies, and the Prentice criteria of surrogacy were met for the PSA kinetic endpoints. A strong correlation was also observed between PSA and radiographic progression-free survival. CONCLUSIONS: The analysis revealed a consistent treatment effect of AA on PSA kinetics and strong associations between PSA kinetics and OS in chemotherapy-pretreated and -naïve patients, thereby providing a rationale to consider PSA kinetics as surrogacy endpoints to indicate clinical benefit in AA-treated patients with mCRPC regardless of chemotherapy treatment.

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.

Updated interim efficacy analysis and long-term safety of abiraterone acetate in metastatic castration-resistant prostate cancer patients without prior chemotherapy (COU-AA-302).

BACKGROUND: Abiraterone acetate (an androgen biosynthesis inhibitor) plus prednisone is approved for treating patients with metastatic castration-resistant prostate cancer (mCRPC). Study COU-AA-302 evaluated abiraterone acetate plus prednisone versus prednisone alone in mildly symptomatic or asymptomatic patients with progressive mCRPC without prior chemotherapy. OBJECTIVE: Report the prespecified third interim analysis (IA) of efficacy and safety outcomes in study COU-AA-302. DESIGN, SETTING, AND PARTICIPANTS: Study COU-AA-302, a double-blind placebo-controlled study, enrolled patients with mCRPC from April 2009 to June 2010. A total of 1088 patients were stratified by Eastern Cooperative Oncology Group performance status (0 vs 1). INTERVENTION: Patients were randomised 1:1 to abiraterone 1000mg plus prednisone 5mg twice daily by mouth versus prednisone. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Co-primary end points were radiographic progression-free survival (rPFS) and overall survival (OS). Median times to event outcomes were estimated using the Kaplan-Meier method. Hazard ratios (HRs) and 95% confidence intervals (CIs) were derived using the Cox model, and treatment comparison used the log-rank test. The O'Brien-Fleming Lan-DeMets α-spending function was used for OS. Adverse events were summarised descriptively. RESULTS AND LIMITATIONS: With a median follow-up duration of 27.1 mo, improvement in rPFS was statistically significant with abiraterone treatment versus prednisone (median: 16.5 vs 8.2 mo; HR: 0.52 [95% CI, 0.45-0.61]; p<0.0001). Abiraterone improved OS (median: 35.3 vs 30.1 mo; HR: 0.79 [95% CI, 0.66-0.95]; p=0.0151) but did not reach the prespecified statistical efficacy boundary (α-level: 0.0035). A post hoc multivariate analysis for OS using known prognostic factors supported the primary results (HR: 0.74 [95% CI, 0.61-0.89]; p=0.0017), and all clinically relevant secondary end points and patient-reported outcomes improved. While the post hoc nature of the long-term safety analysis is a limitation, the safety profile with longer treatment exposure was consistent with prior reports. CONCLUSIONS: The updated IA of study COU-AA-302 in patients with mCRPC without prior chemotherapy confirms that abiraterone delays disease progression, pain, and functional deterioration and has clinical benefit with a favourable safety profile, including in patients treated for ≥24 mo. TRIAL REGISTRATION: Study COU-AA-302, ClinicalTrials.gov number, NCT00887198. PATIENT SUMMARY: The updated results of this ongoing study showed that disease progression was delayed in patients with advanced prostate cancer who were treated with abiraterone acetate and prednisone, and there was a continued trend in prolongation of life compared with patients treated with prednisone alone. Treatment with abiraterone acetate and prednisone was well tolerated by patients who were treated for >2 yr.

Trabectedin plus pegylated liposomal doxorubicin (PLD) versus PLD in recurrent ovarian cancer: overall survival analysis.

AIM: Trabectedin in combination with pegylated liposomal doxorubicin (PLD) improves progression-free survival (PFS) compared to PLD alone in recurrent ovarian cancer (J Clin Oncol 2010;28:3107-14). METHODS: Women, stratified by performance status (0-1 versus 2) and platinum sensitivity (platinum-free interval [PFI]<6 versus ≥ 6 months), were randomly assigned to receive PLD 30 mg/m(2) IV followed by a 3-h infusion of trabectedin 1.1mg/m(2) every 3 weeks or PLD 50mg/m(2) every 4 weeks. The study was powered to show a 33% increase in overall survival (OS) after 520 deaths had occurred. RESULTS: After a median follow-up of 47.4 months, there were 522 deaths among 672 subjects. The median OS for trabectedin+PLD and PLD arms was 22.2 and 18.9 months, respectively (hazard ratio [HR]=0.86; 95% confidence interval [CI]: 0.72-1.02; p=0.0835). An unexpected but significant imbalance in the PFI favouring the PLD arm (mean PFI: PLD=13.3 months, trabectedin+PLD=10.6 months) was identified. On the basis of this finding, an unplanned hypothesis generating analysis adjusting for the PFI imbalance and other prognostic factors suggested an improvement in OS associated with the trabectedin+PLD arm (HR=0.82; 95%CI: 0.69-0.98; p=0.0285). In another unplanned exploratory analysis, the subset of patients with a PFI of 6-12 months had the largest difference in OS (HR=0.64; 95%CI: 0.47-0.86; p=0.0027). CONCLUSIONS: The final OS analysis did not meet the protocol-defined criterion for statistical significance. Despite stratification on platinum sensitivity, there was an imbalance in mean platinum free interval that had an effect on OS.

Trabectedin has a low cardiac risk profile: a comprehensive cardiac safety analysis.

PURPOSE: This analysis provides a cross-study evaluation of the cardiac safety of trabectedin. METHODS: Drug-related cardiac adverse events (CAEs) were retrieved from phase I-III clinical trials, pharmacovigilance databases, and spontaneously reported cases. Left ventricular ejection fraction (LVEF) was monitored in combination phase I studies with doxorubicin or pegylated liposomal doxorubicin (PLD) and in a phase III trial (with PLD). RESULTS: CAEs [grade 4 cardiac arrest with severe pancytopenia and sepsis (n = 1 patient), grade 4 atrial fibrillation (n = 2), and grade 1 tachycardia (n = 1)] occurred in 4/283 patients (1.4%) in 6 single-agent phase I trials. CAEs (grade 1 sinus tachycardia in a hypertensive patient and grade 1 ventricular dysfunction) occurred in 2/155 patients (1.3%) in 4 phase I combination trials. Results from 19 single-agent phase II trials showed CAEs in 20/1,132 patients (1.8%): arrhythmias (tachycardia/palpitations; n = 13; 1.1%) were the most common. A rather similar rate of symptomatic CAEs was observed in both arms of a phase III trial in recurrent ovarian cancer: 6/330 patients (1.8%; PLD) and 11/333 patients (3.3%; trabectedin/PLD). No clinically relevant LVEF changes occurred in phase I combination trials. In the phase III trial, LVEF decreases from baseline were similar: 9% of patients (PLD) and 7% (trabectedin/PLD), with no relevant symptoms. During postmarketing experience in soft tissue sarcoma (2,046 patients treated), 4 CAEs (2 cardiac arrest, 2 cardiac failure; ~0.2%) occurred in patients with preexisting conditions. CONCLUSIONS: Trabectedin has a low incidence of CAEs, consisting mainly of arrhythmias. This extensive data review indicates a low cardiac risk profile for trabectedin.

Efficacy and safety of trabectedin in patients with advanced or metastatic liposarcoma or leiomyosarcoma after failure of prior anthracyclines and ifosfamide: results of a randomized phase II study of two different schedules.

PURPOSE: To evaluate the safety and efficacy of trabectedin in a phase II, open-label, multicenter, randomized study in adult patients with unresectable/metastatic liposarcoma or leiomyosarcoma after failure of prior conventional chemotherapy including anthracyclines and ifosfamide. PATIENTS AND METHODS: Patients were randomly assigned to one of two trabectedin regimens (via central venous access): 1.5 mg/m(2) 24-hour intravenous infusion once every 3 weeks (q3 weeks 24-hour) versus 0.58 mg/m(2) 3-hour IV infusion every week for 3 weeks of a 4-week cycle (qwk 3-hour). Time to progression (TTP) was the primary efficacy end point, based on confirmed independent review of images. RESULTS: Two hundred seventy patients were randomly assigned; 136 (q3 weeks 24-hour) versus 134 (qwk 3-hour). Median TTP was 3.7 months versus 2.3 months (hazard ratio [HR], 0.734; 95% CI, 0.554 to 0.974; P = .0302), favoring the q3 weeks 24-hour arm. Median progression-free survival was 3.3 months versus 2.3 months (HR, 0.755; 95% CI, 0.574 to 0.992; P = .0418). Median overall survival (n = 235 events) was 13.9 months versus 11.8 months (HR, 0.843; 95% CI, 0.653 to 1.090; P = .1920). Although somewhat more neutropenia, elevations in AST/ALT, emesis, and fatigue occurred in the q3 weeks 24-hour, this regimen was reasonably well tolerated. Febrile neutropenia was rare (0.8%). No cumulative toxicities were noted. CONCLUSION: Prior studies showed clinical benefit with trabectedin in patients with sarcomas after failure of standard chemotherapy. This trial documents superior disease control with the q3 weeks 24-hour trabectedin regimen in liposarcomas and leiomyosarcomas, although the qwk 3-hour regimen also demonstrated activity relative to historical comparisons. Trabectedin may now be considered an important new option to control advanced sarcomas in patients after failure of available standard-of-care therapies.

A randomized phase 3 study of tipifarnib compared with best supportive care, including hydroxyurea, in the treatment of newly diagnosed acute myeloid leukemia in patients 70 years or older.

This phase 3, multicenter, open-label study evaluated the efficacy and safety of tipifarnib compared with best supportive care (BSC), including hydroxyurea, as first-line therapy in elderly patients (>or=70 years) with newly diagnosed, de novo, or secondary acute myeloid leukemia. A total of 457 patients were enrolled with 24% 80 years of age or older. Tipifarnib 600 mg orally twice a day was administered for the first 21 consecutive days, in 28-day cycles. The primary endpoint was overall survival. The median survival was 107 days for the tipifarnib arm and 109 days for the BSC arm. The hazard ratio (tipifarnib vs BSC) for overall survival was 1.02 (P value by stratified log-rank test, .843). The complete response rate for tipifarnib in this study (8%) was lower than that observed previously, but with a similar median duration of 8 months. The most frequent grade 3 or 4 adverse events were cytopenias in both arms, slightly more infections (39% vs 33%), and febrile neutropenia (16% vs 10%) seen in the tipifarnib arm. The results of this randomized study showed that tipifarnib treatment did not result in an increased survival compared with BSC, including hydroxyurea. This trial was registered at www.clinicaltrials.gov as #NCT00093990.

A phase II, randomized, blinded study of the farnesyltransferase inhibitor tipifarnib combined with letrozole in the treatment of advanced breast cancer after antiestrogen therapy.

BACKGROUND: This study assessed the clinical efficacy of the farnesyltransferase inhibitor, tipifarnib, combined with letrozole in patients with advanced breast cancer and disease progression following antiestrogen therapy. PATIENTS AND METHODS: Postmenopausal women with estrogen-receptor-positive advanced breast cancer that had progressed after tamoxifen were given 2.5 mg letrozole once daily and were randomly assigned (2:1) to tipifarnib 300 mg (TL) or placebo (L) twice daily for 21 consecutive days in 28-day cycles. The primary endpoint was objective response rate. RESULTS: Of 120 patients treated with TL (n = 80) or L (n = 40), 113 were evaluable for response. Objective response rate was 30% (95% CI; 20-41%) for TL and 38% (95% CI; 23-55%) for L. There was no significant difference in response duration, time to disease progression or survival. Clinical benefit rates were 49% (TL) and 62% (L). Tipifarnib was generally well tolerated; a higher incidence of drug-related asymptomatic grade 3/4 neutropenia was observed for TL (18%) than for L (0%). Tipifarnib population pharmacokinetics were similar to previous studies, with no significant difference in trough letrozole concentrations between the TL and L groups. CONCLUSIONS: Adding tipifarnib to letrozole did not improve objective response rate in this population of patients with advanced breast cancer.