Quality of life in patients with metastatic prostate cancer following treatment with cabazitaxel versus abiraterone or enzalutamide (CARD): an analysis of a randomised, multicentre, open-label, phase 4 study.

BACKGROUND: In the CARD study, cabazitaxel significantly improved radiographic progression-free survival and overall survival versus abiraterone or enzalutamide in patients with metastatic castration-resistant prostate cancer previously treated with docetaxel and the alternative androgen signalling-targeted inhibitor. Here, we report the quality-of-life outcomes from the CARD study. METHODS: CARD was a randomised, multicentre, open-label, phase 4 study involving 62 clinical sites across 13 European countries. Patients (aged ≥18 years, Eastern Cooperative Oncology Group (ECOG) performance status ≤2) with confirmed metastatic castration-resistant prostate cancer were randomly assigned (1:1) by means of an interactive voice-web response system to receive cabazitaxel (25 mg/m2 intravenously every 3 weeks, 10 mg daily prednisone, and granulocyte colony-stimulating factor) versus abiraterone (1000 mg orally once daily plus 5 mg prednisone twice daily) or enzalutamide (160 mg orally daily). Stratification factors were ECOG performance status, time to disease progression on the previous androgen signalling-targeted inhibitor, and timing of the previous androgen signalling-targeted inhibitor. The primary endpoint was radiographic progression-free survival; here, we present more detailed analyses of pain (assessed using item 3 on the Brief Pain Inventory-Short Form [BPI-SF]) and symptomatic skeletal events, alongside preplanned patient-reported outcomes, assessed using the Functional Assessment of Cancer Therapy-Prostate (FACT-P) questionnaire and the EuroQoL-5 dimensions, 5 level scale (EQ-5D-5L). Efficacy analyses were done in the intention-to-treat population. Pain response was analysed in the intention-to-treat population with baseline and at least one post-baseline assessment of BPI-SF item 3, and patient-reported outcomes (PROs) were analysed in the intention-to-treat population with baseline and at least one post-baseline assessment of either FACT-P or EQ-5D-5L (PRO population). Analyses of skeletal-related events were also done in the intention-to-treat population. The CARD study is registered with ClinicalTrials.gov, NCT02485691, and is no longer enrolling. FINDINGS: Between Nov 17, 2015, and Nov 28, 2018, of 303 patients screened, 255 were randomly assigned to cabazitaxel (n=129) or abiraterone or enzalutamide (n=126). Median follow-up was 9·2 months (IQR 5·6-13·1). Pain response was observed in 51 (46%) of 111 patients with cabazitaxel and 21 (19%) of 109 patients with abiraterone or enzalutamide (p<0·0001). Median time to pain progression was not estimable (NE; 95% CI NE-NE) with cabazitaxel and 8·5 months (4·9-NE) with abiraterone or enzalutamide (hazard ratio [HR] 0·55, 95% CI 0·32-0·97; log-rank p=0·035). Median time to symptomatic skeletal events was NE (95% CI 20·0-NE) with cabazitaxel and 16·7 months (10·8-NE) with abiraterone or enzalutamide (HR 0·59, 95% CI 0·35-1·01; log-rank p=0·050). Median time to FACT-P total score deterioration was 14·8 months (95% CI 6·3-NE) with cabazitaxel and 8·9 months (6·3-NE) with abiraterone or enzalutamide (HR 0·72, 95% CI 0·44-1·20; log-rank p=0·21). There was a significant treatment effect seen in changes from baseline in EQ-5D-5L utility index score in favour of cabazitaxel over abiraterone or enzalutamide (p=0·030) but no difference between treatment groups for change from baseline in EQ-5D-5L visual analogue scale (p=0·060). INTERPRETATION: Since cabazitaxel improved pain response, time to pain progression, time to symptomatic skeletal events, and EQ-5D-5L utility index, clinicians and patients with metastatic castration-resistant prostate cancer can be reassured that cabazitaxel will not reduce quality of life when compared with treatment with a second androgen signalling-targeted inhibitor. FUNDING: Sanofi.

Managing Nonmetastatic Castration-resistant Prostate Cancer.

CONTEXT: Patients with nonmetastatic castration-resistant prostate cancer (nmCRPC) have rising prostate-specific antigen (PSA) and castrate testosterone levels, with no radiological findings of metastatic disease on computed tomography and bone scan. Given recent drug approvals for nmCRPC, with many other therapeutics and imaging modalities being developed, management of nmCRPC is a rapidly evolving field that merits detailed investigation. OBJECTIVE: To review current nmCRPC management practices and identify opportunities for improving care of nmCRPC patients. EVIDENCE ACQUISITION: A literature search up to July 2018 was conducted, including clinical trials and clinical practice guidelines (National Comprehensive Cancer Network, European Society for Medical Oncology, European Association of Urology, Prostate Cancer Clinical Trials Working Group, Prostate Cancer Radiographic Assessments for Detection of Advanced Recurrence). Keywords included prostate cancer, nonmetastatic, castration resistance, rising PSA, and biochemical relapse. EVIDENCE SYNTHESIS: Recommendations regarding indications for, and frequency of, imaging and PSA testing, as well as for initiating systemic therapy in nmCRPC are based on PSA rise kinetics and symptoms. Both enzalutamide and apalutamide have been shown to significantly increase metastasis-free survival in phase III placebo-controlled randomised trials in nmCRPC patients with PSA doubling time (DT) ≤10 mo. The expected impact of new imaging techniques in the assessment of nmCRPC is also reviewed. CONCLUSIONS: nmCRPC is a heterogeneous disease; while observation may be an option for some patients, enzalutamide and apalutamide may be appropriate to treat nmCRPC patients with PSA-DT ≤10 mo. The emergence of more accurate imaging modalities as well as circulating tumour biomarker assays will likely redefine the assessment of nmCRPC in the near future. PATIENT SUMMARY: Herein, we review key literature and clinical practice guidelines to summarise the optimal management of patients with prostate cancer and rising prostate-specific antigen despite castrate testosterone levels, but with no evidence of distant metastasis on traditional imaging. New drugs are being developed for this disease setting; novel imaging and tumour biomarker blood tests are likely to define this disease state more accurately.

Effect on Overall Survival of Locoregional Treatment in a Cohort of De Novo Metastatic Prostate Cancer Patients: A Single Institution Retrospective Analysis From the Royal Marsden Hospital.

BACKGROUND: The optimal management of the primary tumor in metastatic at diagnosis (M1) prostate cancer (PCa) patients is not yet established. We retrospectively evaluated the effect of locoregional treatment (LRT) on overall survival (OS) hypothesizing that this could improve outcome through better local disease control and the induction of an antitumor immune response (abscopal effect). PATIENTS AND METHODS: M1 at diagnosis PCa patients referred to the Prostate Targeted Therapy Group at the Royal Marsden between June 2003 and December 2013 were identified. LRT was defined as either surgery, radiotherapy (RT) or transurethral prostatectomy (TURP) administered to the primary tumor at any time point from diagnosis to death. Kaplan-Meier analyses generated OS data. The association between LRT and OS was evaluated in univariate (UV) and multivariate (MV) Cox regression models. RESULTS: Overall 300 patients were identified; 192 patients (64%) experienced local symptoms at some point during their disease course; 72 patients received LRT (56.9% TURP, 52.7% RT). None of the patients were treated with prostatectomy. LRT was more frequently performed in patients with low volume disease (35.4% vs. 16.2%; P < .001), lower prostate-specific antigen (PSA) level at diagnosis (median PSA: 75 vs. 184 ng/mL; P = .005) and local symptoms (34.2% vs. 4.8%; P < .001). LRT was associated in UV and MV analysis with longer OS (62.1 vs. 55.8 months; hazard ratio [HR], 0.74; P = .044), which remained significant for RT (69.4 vs. 55.1 months; HR, 0.54; P = .002) but not for TURP. RT was associated with better OS independent of disease volume at diagnosis. CONCLUSION: These data support the conduct of randomized phase III trials to evaluate the benefit of local control in patients with M1 disease at diagnosis.

Cabazitaxel in metastatic castration-resistant prostate cancer.

Metastatic castration-resistant prostate cancer (CRPC) has a poor prognosis and remains a significant therapeutic challenge. Prior to 2010, docetaxel chemotherapy was the only treatment shown to improve overall survival, symptom control and quality of life in patients with CRPC. Research efforts focused on overcoming chemoresistance to taxanes eventually led to the development of multiple novel anti-tumor agents, including cabazitaxel. Cabazitaxel has recently been shown to significantly improve overall survival compared with mitoxantrone in a large multicenter Phase III study. This article details the preclinical and clinical development of cabazitaxel and discusses the importance of this novel chemotherapy in CRPC. The authors also discuss the challenges now facing the future use of cabazitaxel in CRPC, including the determination of the optimal dose of cabazitaxel in patients with advanced CRPC, the ideal sequencing of cabazitaxel relative to other anti-tumor treatments, appropriate patient selection and novel strategies for the assessment of treatment response.

Abiraterone acetate: redefining hormone treatment for advanced prostate cancer.

Prostate cancer has long since been recognised as being hormonally driven via androgen receptor signalling. Abiraterone acetate (AA) is a rationally designed CYP17 inhibitor that blocks the conversion of androgens from non-gonadal precursors effectively, thus reducing testosterone to undetectable levels. AA has recently been proved to extend survival for men with metastatic castration-resistant prostate cancer who have progressive disease after first-line chemotherapy treatment. In addition, it is currently being tested in a Phase III trial in the pre-chemotherapy setting. This paper will review the preclinical discovery and clinical development of AA and will outline the strategy of parallel translational research.

Clinical and biochemical consequences of CYP17A1 inhibition with abiraterone given with and without exogenous glucocorticoids in castrate men with advanced prostate cancer.

CONTEXT: Abiraterone acetate is a small-molecule cytochrome P450 17A1 (CYP17A1) inhibitor that is active in castration-resistant prostate cancer. OBJECTIVE: Our objective was to determine the impact of abiraterone with and without dexamethasone treatment on in vivo steroidogenesis. DESIGN AND METHODS: We treated 42 castrate, castration-resistant prostate cancer patients with continuous, daily abiraterone acetate and prospectively collected blood and urine before and during abiraterone treatment and after addition of dexamethasone 0.5 mg daily. RESULTS: Treatment with single-agent abiraterone acetate was associated with accumulation of steroids with mineralocorticoid properties upstream of CYP17A1. This resulted in side effects, including hypertension, hypokalemia, and fluid overload, in 38 of 42 patients that were generally treated effectively with eplerenone. Importantly, serum and urinary androgens were suppressed by more than 90% from baseline. Urinary metabolites of 17-hydroxypregnenolone and 17-hydroxyprogesterone downstream of 17α-hydroxylase remained unchanged. However, 3α5α-17-hydroxypregnanolone, which can be converted via the backdoor pathway toward 5α-dihydrotestosterone, increased significantly and correlated with levels of the major 5α-dihydrotestosterone metabolite androsterone. In contrast, urinary metabolites of 11-deoxycortisol and active glucocorticoids declined significantly. Addition of dexamethasone to abiraterone acetate significantly suppressed ACTH and endogenous steroids, including 3α5α-17-hydroxypregnanolone. CONCLUSION: CYP17A1 inhibition with abiraterone acetate is characterized by significant suppression of androgen and cortisol synthesis. The latter is associated with a rise in ACTH that causes raised mineralocorticoids, leading to side effects and incomplete 17α-hydroxylase inhibition. Concomitant inhibition of 17,20-lyase results in diversion of 17-hydroxyprogesterone metabolites toward androgen synthesis via the backdoor pathway. Addition of dexamethasone reverses toxicity and could further suppress androgens by preventing a rise in substrates of backdoor androgen synthesis.

Phase I and pharmacokinetic study of pemetrexed with high-dose folic acid supplementation or multivitamin supplementation in patients with locally advanced or metastatic cancer.

PURPOSE: This phase I study evaluated the effect of folate supplementation on the toxicity, tolerability, and pharmacokinetics of pemetrexed in patients with locally advanced or metastatic cancer. It also examined two different types of vitamin supplementation and whether the extent of prior myelosuppressive therapy affected pemetrexed tolerability. PATIENTS AND METHODS: Patients received a 10-min infusion of 600 to 14,00 mg/m(2) pemetrexed every 3 weeks. Patients were stratified into cohorts by pretreatment status [lightly pretreated (LPT) or heavily pretreated (HPT)] and were supplemented with intermittent high-dose folic acid (HDFA) or with continuous daily multivitamins (MVI) containing nutritional doses of folic acid. Pemetrexed plasma pharmacokinetics were evaluated for cycle 1. RESULTS: Sixty-two HDFA patients (28 HPT and 34 LPT) were treated with 204 cycles of pemetrexed, and 43 MVI patients (20 HPT and 23 LPT) were treated with 182 cycles. Hematologic dose-limiting toxicities included grade 4 neutropenia (5 of 105 patients), grade 4 thrombocytopenia (4 of 105 patients), and febrile neutropenia (3 of 105 patients). Nonhematologic toxicities included fatigue, vomiting, diarrhea, and nausea. Pemetrexed doses of 800 and 1,050 mg/m(2) were well tolerated when administered with vitamin supplementation to HPT and LPT patients, respectively. There were no clinically relevant differences in toxicities or pemetrexed pharmacokinetics for LPT versus HPT patients or for patients receiving HDFA versus daily MVI supplementation. CONCLUSIONS: The pemetrexed doses tolerated in this study with vitamin supplementation were significantly higher than those tolerated in earlier studies without supplementation, and toxicities were independent of the type of vitamin supplementation or prior myelosuppressive treatment. The recommended dose of pemetrexed is 1,050 mg/m(2) in LPT patients and 800 mg/m(2) in HPT patients, irrespective of the type of vitamin supplementation.

A phase I and pharmacokinetic study of pemetrexed plus irinotecan in patients with advanced solid malignancies.

PURPOSE: The main objectives of this phase I and pharmacokinetic, open-label study were to characterize the principal toxicities and determine the maximum tolerated dose of the multitargeted antifolate pemetrexed administered in combination with irinotecan. The study also sought to detect major pharmacokinetic drug-drug interactions between these agents and preliminary evidence of antitumor activity in patients with advanced solid malignancies. EXPERIMENTAL DESIGN: Pemetrexed was administered as a 10-min i.v. infusion followed by irinotecan given i.v. over 90 min every 3 weeks to patients with advanced solid malignancies. The study objectives were first pursued in heavily pretreated patients and then in lightly pretreated patients who also received vitamin supplementation. RESULTS: Twenty-three heavily pretreated patients enrolled in the first stage of the study, and the maximum tolerated dose level of pemetrexed/irinotecan without vitamin supplementation was 400/250 mg/m(2); further dose escalation was precluded by severe neutropenia that was protracted and/or associated with fever. In the second stage of the study, 28 lightly pretreated patients were administered pemetrexed/irinotecan with vitamin supplementation; these patients tolerated pemetrexed/irinotecan at a dose level of 500/350 mg/m(2), which reflected clinically relevant single-agent doses of both agents. No major pharmacokinetic interactions between the agents were evident. Four patients, two patients each with colorectal cancer refractory to fluoropyrimidines and advanced mesothelioma, had partial responses. CONCLUSIONS: The pemetrexed/irinotecan regimen is well tolerated in patients with advanced solid malignancies at clinically relevant single-agent doses. The recommended dose level of pemetrexed/irinotecan for subsequent disease-directed evaluations involving lightly pretreated patients is 500/350 mg/m(2) every 3 weeks with vitamin supplementation.