Results From a Large,Multicenter, Retrospective Analysis On Radium223 Use in Metastatic Castration-resistant Prostate Cancer (mCRPC) in the Triveneto Italian Region

Background

Radium 223 was introduced for metastatic castration-resistant prostate cancer based on the results of a randomized controlled trial showing risk reduction for death and skeletal events. Our aim was to evaluate the outcome of patients receiving radium 223 in a real-world setting.

Disease Characteristics and Completion of Treatment in Patients With Metastatic Castration-Resistant Prostate Cancer Treated With Radium-223 in an International Early Access Program

BackgroundRadium-223 is approved by the US Food and Drug Administration and European Medicines Agency for the treatment of metastatic castration-resistant prostate cancer (mCRPC). There are currently no markers for selecting patients most likely to complete radium-223 treatment.Patients and MethodsIn this phase IIIb, international, single-arm study, patients received radium-223, 55 kBq/kg, every 4 weeks for ≤6 cycles. Primary end points were safety and overall survival. In post hoc analyses patients were grouped according to number of radium-223 injections received (1-4 or 5-6). Associations between baseline covariates and number of injections were investigated.ResultsOf 696 eligible patients, 473 (68%) had received 5 to 6 radium-223 injections and 223 (32%) 1 to 4 injections. Patients with less pain (moderate-severe vs. none-mild, odds ratio [OR], 0.41; P < .0001), lower Eastern Cooperative Oncology Group performance status (≥2 vs. 0-1, OR, 0.51; P = .0074), lower prostate-specific antigen level (>141 μg/L vs. ≤141 μg/L, OR, 0.40; P < .0001), and higher hemoglobin level (<10 g/dL vs. ≥10 g/dL, OR, 0.50; P = .0206) were more likely to receive 5 to 6 than 1 to 4 injections. Median overall survival was not reached and was 6.3 months (95% confidence interval, 5.4-7.4) in patients who had received 5 to 6 and 1 to 4 radium-223 injections, respectively. Adverse events were less common in patients who received 5 to 6 than 1 to 4 injections; anemia was reported in 87 (18%) and 64 (29%) patients, respectively.ConclusionPatients with less advanced mCRPC are more likely to receive 5 to 6 radium-223 injections and to achieve better overall survival. Consideration of baseline and disease characteristics is recommended before initiation of radium-223 treatment.     

Immune Analysis of Radium-223 in Patients With Metastatic Prostate Cancer

Background

Radium223 (Ra223) delivers high-energy radiation to osteoblastic metastasis of prostate cancer, resulting in irreparable double-stranded DNA damage. The effects of Ra223 on CD8+ T cell subsets in patients with prostate cancer is unknown.

A Phase II,Nonrandomized Open Trial Assessing Pain Efficacy with Radium-223 in Symptomatic Metastatic Castration-resistant Prostate Cancer

BackgroundProstate Cancer Working Group 3 and FDA guidelines recommend a standardized approach to pain assessment in preapproval trials. No prior trial has examined pain palliation of Radium-223 using standard dosing and contemporary PRO pain-assessment tools.MethodsIn this multicenter phase II trial, patients with Brief Pain Inventory (BPI) ≥3 were eligible for Radium-223 per its label. Primary endpoint was a 30% decrease in BPI Worst Pain from baseline to Week 8, sustained at Week 12 without escalation of medication on the World Health Organization (WHO) analgesic ladder. Secondary endpoints included changes in Brief Fatigue Inventory (BFI) Worst fatigue and BPI pain interference. If six of 27 subjects (22%) met the primary endpoint, the trial would expand by another 36 subjects.ResultsTwenty-nine subjects were accrued. Nine of 29 (31%) subjects met the primary endpoint, with 21 (72%) evaluable for the primary endpoint. Among responders: median worst pain declined 62% (range 36–100) at Week 8 and 63% (range 38–100) at Week 12; median reduction of pain interference with general activity and sleep at Week 12 was 62% (range 18–100) and 53% (range 8–100) respectively; median reduction in worst fatigue of 45% (range 10–85) at Week 12.ConclusionsIn the first prospective trial using standard Ra-223 doses, contemporary pain endpoints and PRO collection tools, Ra-223 palliated pain, reduced fatigue, and improved pain interference. The pain response rate easily exceeded the requirements for expansion to the second phase, but the trial was closed due to slow accrual.     

Fracture Risk in Men with Metastatic Prostate Cancer Treated With Radium-223

BackgroundRadium-223 is a bone-seeking, alpha-emitting radionuclide used in metastatic castration-resistant prostate cancer (mCRPC). Radium-223 increases the risk of fracture when used in combination with abiraterone and prednisolone. The risk of fracture in men receiving radium-223 monotherapy is unclear.Patients and MethodsThis was a prospective, multicenter phase II study of radium-223 in 36 men with mCRPC and a reference cohort (n = 36) matched for fracture risk and not treated with radium-223. Bone fractures were assessed using whole-body magnetic resonance imaging. The primary outcome was risk of new fractures.ResultsThirty-six patients were treated with up to six 4-week cycles of radium-223. With a median follow-up of 16.3 months, 74 new fractures were identified in 20 patients. Freedom from fracture was 56% (95% confidence interval, 35.3-71.6) at 12 months. On multivariate analysis, prior corticosteroid use was associated with risk of fracture. In the reference cohort (n = 36), 16 new fractures were identified in 12 patients over a median follow-up of 24 months. Across both cohorts, 67% of all fractures occurred at uninvolved bone.ConclusionsMen with mCRPC, and particularly those treated with radium-223, are at risk of fracture. They should receive a bone health agent to reduce the risk of fragility fractures.     

Circulating Tumor Cells as a Biomarker of Survival and Response to Radium-223 Therapy: Experience in a Cohort of Patients With Metastatic Castration-Resistant Prostate Cancer

Introduction

Although increasing numbers of therapies with proven survival benefits have become available for metastatic castration-resistant prostate cancer (mCRPC), including radium-223, there is still a need for reliable biomarkers that provide information about clinically meaningful outcomes and treatment responses.

Is There a Flare Phenomenon on Bone Scintigraphy in Men With Advanced Prostate Cancer Treated With Radium-223?

Introduction

Radium-223 is an approved survival-prolonging treatment option in men with castration-resistant prostate cancer (mCRPC) and bone metastases. In the registration trial (ALSYMPCA), no regular imaging was mandated. We aimed to analyze men with metastatic mCRPC treated with radium-223 who had bone scintigraphy for staging and treatment monitoring.

The Effect of Treatment Sequence on Overall Survival for Men With Metastatic Castration-resistant Prostate Cancer: A Multicenter Retrospective Study

IntroductionWe aimed to evaluate the treatment sequence for patients with metastatic castration-resistant prostate cancer (mCRPC) in real-world practice and compare overall survival in each sequential therapy.Patients and MethodsWe retrospectively evaluated 146 patients with mCRPC who were initially treated with androgen deprivation therapy as metastatic hormone-naive prostate cancer in 14 hospitals between January 2010 and March 2019. The agents for the sequential therapy included new androgen receptor-targeted agents (ART: abiraterone acetate or enzalutamide), docetaxel, and/or cabazitaxel. We evaluated the treatment sequence for mCRPC and the effect of sequence patterns on overall survival.ResultsThe median age was 71 years. A total of 35 patients received ART-ART, 33 received ART-docetaxel, 68 received docetaxel-ART, and 10 received docetaxel-cabazitaxel sequences. The most prescribed treatment sequence was docetaxel-ART (47%), followed by ART-ART (24%). Overall survival calculated from the initial diagnosis reached 83, 57, 79, and 37 months in the ART-ART, ART-docetaxel, docetaxel-ART, and docetaxel-cabazitaxel, respectively. Multivariate Cox regression analyses showed no significant difference in overall survival between the first-line ART (n = 68) and first-line docetaxel (n = 78) therapies (hazard ratio [HR], 0.84; P = .530), between the ART-ART (n = 35) and docetaxel-mixed (n = 111) sequences (HR, 0.82; P = .650), and between the first-line abiraterone (n = 32) and first-line enzalutamide (n = 36) sequences (HR, 1.58; P = .384).ConclusionThe most prescribed treatment sequence was docetaxel followed by ART. No significant difference was observed in overall survival among the treatment sequences in real-world practice.     

Evaluation of Response to Enzalutamide Consecutively After Abiraterone Acetate/Prednisone Failure in Patients With Metastatic Castration-resistant Prostate Cancer

Introduction

Treatment of metastatic castration-resistant prostate cancer (mCRPC) has evolved significantly during the past decade, and the preferred combination and/or sequence of these treatments remains controversial. In this retrospective study, we explored clinical and pathologic factors that could predict response to consecutive treatment with enzalutamide (ENZA) after disease progression (PD) on abiraterone acetate and prednisone (AA/P).

前列腺癌骨转移治疗的研究进展

前列腺癌（prostate cancer, PCa）骨转移的发生率很高,不仅引发疼痛、增加骨相关事件的风险,还严重影响患者的生活质量以及缩短其生存期。近年来,随着对PCa骨转移机制以及肿瘤细胞和骨微环境之间相关调控作用的认知不断深入,许多新药被开发和批准用于抑制骨转移的“恶性循环”,减少骨转移引起的并发症,使PCa骨转移治疗取得重大进展。本文从PCa骨转移机制、骨靶向药物治疗和非骨特异性抗癌药物治疗研究进展方面进行综述,以期为临床医生提供更多的治疗选择。     

Radium-223 in the Third-Line Setting in Metastatic Castration-Resistant Prostate Cancer: Impact of Concomitant Use of Enzalutamide on Overall Survival (OS) and Predictors of Improved OS

IntroductionRadium-223 (Ra-223) has been recommended for bone-dominant metastatic castration-resistant prostate cancer (mCRPC). Second-generation hormone therapy in combination with Ra-223 in mCRPC has been utilized, yet its benefit has not been well elucidated. We investigated the potential survival benefit of concomitant enzalutamide with Ra-223 in the third-line setting and predictors of improved overall survival (OS).Patients and MethodsWe retrospectively identified 51 patients with bone-dominant mCRPC that were treated with Ra-223 in the postchemotherapy and post–hormone therapy setting, either alone (group A; n = 32) or with concomitant enzalutamide (group B; n = 19). The primary endpoint was to study the OS difference between groups A and B. The secondary endpoint was to identify predictors of improved OS with Ra-223 in the third-line setting.ResultsMean age was 70.9 years, median baseline prostatic-specific antigen (PSA) was 23.1 ng/mL, alkaline phosphatase was 91 IU/L, and hemoglobin was 12.5 g/dL. There was no difference in median OS between groups A and B, at 20.4 versus 17.5 months, respectively (P = .5186). In univariate and multivariate analyses, only pre–Ra-223 PSA < 30 ng/mL and Eastern Cooperative Oncology Group performance status < 2 were associated with improved OS.ConclusionIn our study cohort, concomitant use of enzalutamide with Ra-223 in the mCRPC setting was not associated with improved OS. Only pretreatment PSA < 30 ng/mL and pretreatment Eastern Cooperative Oncology Group performance status < 2 were associated with improved OS. Further prospective studies are warranted.     

Hematologic Toxicity From Radium-223 Therapy for Bone Metastases in Castration-Resistant Prostate Cancer: Risk Factors and Practical Considerations

Radium-223 dichloride is an α-emitting radiopharmaceutical that localizes to bone matrix and is approved for the treatment of patients with metastatic castration-resistant prostate cancer (CRPC) and symptomatic bone metastases. The cumulative impact of Ra-223 and other therapeutic agents for metastatic CRPC on myelosuppression in bone marrow is unknown. The phase 3 randomized, double-blind, placebo-controlled ALSYMPCA trial of Ra-223 in patients with CRPC and symptomatic bone metastases demonstrated a significant improvement in overall survival. Of the 571 patients subsequently followed for 3 years, few in either the Ra-223 or placebo arm experienced hematologic adverse events. Little evidence shows secondary malignancies associated with Ra-223 treatment; only 2 cases of secondary leukemia after Ra-223 treatment were found in the literature. The goals of this review were to summarize safety and efficacy results from clinical trials and institutional safety data pertaining to hematologic adverse events occurring with Ra-223, and to discuss practical management issues.