Systemic therapy in men with metastatic castration-resistant prostate cancer:American Society of Clinical Oncology and Cancer Care Ontario clinical practice guideline

Abiraterone acetate for chemotherapy-naive metastatic castration-resistant prostate cancer: a single-centre prospective study of efficacy, safety, and prognostic factors

Background

To evaluate the efficacy and safety of abiraterone acetate (AA) plus prednisone compared with prednisone alone in Asian patients with chemotherapy-naive metastatic castration-resistant prostate cancer (mCRPC), and to identify predictive factors.

Methods

We reviewed the medical records of 60 patients with chemotherapy-naive mCRPC at Renji Hospital who were treated with AA plus prednisone (n = 43) or prednisone alone (n = 17). All patients were assessed for prostate-specific antigen (PSA) response, PSA progression-free survival (PSA PFS), radiographic progression-free survival (rPFS), and overall survival (OS). The ability of several parameters to predict PSA PFS, rPFS, and OS was studied.

Results

The median follow-up time was 14.0 months (range 7.0–18.5 months), at which time 19 death events had been reported: 11 in the AA + prednisone group and 8 in the prednisone group. The AA + prednisone group had significantly longer median PSA PFS (10.3 vs 3.0 months, P < 0.001), rPFS (13.9 vs 3.9 months, P < 0.001), and OS (23.3 vs 17.5 months, P = 0.016) than the prednisone-alone group. The most frequently reported grade 3 or 4 adverse event in both the AA + prednisone and prednisone-alone groups was elevated alanine aminotransferase level in 5 of 43 patients (11.6%) and 2 of 17 patients (11.8%), respectively. No adverse events led to discontinuation of therapy. In multivariate analysis, time from androgen deprivation therapy (ADT) to castration resistance of ≤18 months was a determinant of shorter OS (P = 0.007).

Conclusions

These results support the favourable safety and efficacy profile of AA for the treatment of Asian patients with chemotherapy-naive mCRPC. Longer duration of ADT response was significantly associated with longer survival.

Electronic supplementary material

The online version of this article (10.1186/s12894-018-0416-6) contains supplementary material, which is available to authorized users.

Metastatic prostate cancer remains incurable, why?

Metastatic prostate cancer patients present in two ways—with already disseminated disease at the time of presentation or with disease recurrence after definitive local therapy. Androgen deprivation therapy is given as the most effective initial treatment to patients. However, after the initial response, almost all patients will eventually progress despite the low levels of testosterone. Disease at this stage is termed castration resistant prostate cancer (CRPC). Before 2010, the taxane docetaxel was the first and only life prolonging agent for metastatic CRPC (mCRPC). The last decade has witnessed robust progress in CRPC therapeutics development. Abiraterone, enzalutamide, apalutamide and sipuleucel-T have been evaluated as first- and second-line agents in mCRPC patients, while cabazitaxel was approved as a second-line treatment. Radium-223 dichloride was approved in symptomatic patients with bone metastases and no known visceral metastases pre- and post-docetaxel. However, despite significant advances, mCRPC remains a lethal disease. Both primary and acquired resistance have been observed in CRPC patients treated by these new agents. It could be solely cell intrinsic or it is possible that the clonal heterogeneity in treated tumors may result from the adaptive responses to the selective pressures within the tumor microenvironment. The aim of this review is to list current treatment agents of CRPC and summarize recent findings in therapeutic resistance mechanisms.

Identification of subgroups of metastatic castrate-resistant prostate cancer (mCRPC) patients treated with abiraterone plus prednisone at low- vs. high-risk of radiographic progression: An analysis of COU-AA-302

INTRODUCTION

Radiographic imaging is used to monitor disease progression for men with metastatic castrate-resistant prostate cancer (mCRPC). The optimal frequency of imaging, a costly and limited resource, is not known. Our objective was to identify predictors of radiographic progression to inform the frequency of imaging for men with mCRPC.

METHODS

We accessed data for men with chemotherapy-naive mCRPC in the abiraterone acetate plus prednisone (AA-P) group of a randomized trial (COU-AA-302) (n=546). We used Cox proportional hazards modelling to identify predictors of time to progression. We divided patients into groups based on the most important predictors and estimated the probability of radiographic progression-free survival (RPFS) at six and 12 months.

RESULTS

Baseline disease and change in prostate-specific antigen (PSA) at eight weeks were the strongest determinants of RPFS. The probability of RPFS for men with bone-only disease and a ≥50% fall in PSA was 93% (95% confidence interval [CI] 87-96) at six months and 80% (95% CI 72-86) at 12 months. In contrast, the probability of RPFS for men with bone and soft tissue metastasis and <50% fall in PSA was 55% (95% CI 41-67) at six months and 34% (95% CI 22-47) at 12 months. These findings should be externally validated.

CONCLUSIONS

Patients with chemotherapy-naive mCRPC treated with first-line AA-P can be divided into groups with significantly different risks of radiographic progression based on a few clinically available variables, suggesting that imaging schedules could be individualized.

Inhibition of BRD4 suppresses tumor growth in prostate cancer via the enhancement of FOXO1 expression

Prostate cancer (PCa) is a malignant tumor with a high incidence in males. Localized tumors can be treated via surgery or radiation; however, it remains difficult to prevent disease progression. Bromodomain-containing protein 4 (BRD4) is an epigenetic reader protein that binds to acetylated lysine on histones and has been reported to serve critical roles in numerous types of cancers. In the present study, it was demonstrated that BRD4 expression levels were significantly increased in cancerous prostate tissue specimens and cells, which were associated with clinical stage and metastasis. In addition, the present study reported that inhibition of BRD4 via short hairpin RNA or JQ1 (a bromo-domain inhibitor) decreased PCa cell proliferation, induced G0/G1 cell cycle arrest and apoptosis, mitigated cell invasion and migration in vitro, and impaired tumor growth in vivo. Mechanistically, BRD4 inhibition-induced suppression of cell cycle progression was associated with the upregulation of p21 and cyclin D1. c-Myc and B-cell lymphoma-2 (Bcl-2), important genes responsible for cell cycle regulation and anti-apoptotic functions, were downregulated in response to BRD4 inhibition. Furthermore, the present study revealed that c-Myc expression was negatively regulated by p21, and that the induction of p21 via BRD4 inhibition was mediated by forkhead box protein O1 (FOXO1), rather than p53. In summary, the results of the present study suggested that the aberrant expression of BRD4 in PCa may induce carcinogenesis. In addition, a mechanism by which BRD4 inhibition suppresses cell proliferation via the regulation of FOXO1-p21-Myc signaling was proposed in the present study, which may contribute to the development of novel therapeutic approaches in the management of PCa.

Number-needed-to-treat analysis of clinical progression in patients with metastatic castration-resistant prostate cancer in the STRIVE and TERRAIN trials

BACKGROUND

This analysis estimated the number needed to treat with enzalutamide versus bicalutamide to achieve one additional patient with chemotherapy-naïve metastatic castration-resistant prostate cancer who would obtain clinical benefit regarding progression-free survival, radiographic progression-free survival, or no prostate-specific antigen progression at 1 and 2 years following treatment initiation.

METHODS

Clinical event rates were obtained from the STRIVE (NCT01664923) and TERRAIN (NCT01288911) trials, and the number needed to treat was the inverse of the absolute rate difference between the event rates of enzalutamide and bicalutamide. The 95% Confidence Interval of the number needed to treat was derived from the 95% Confidence Interval of the event rate difference.

RESULTS

Using STRIVE data (patients with metastatic disease: n = 128 enzalutamide; n = 129 bicalutamide) comparing enzalutamide with bicalutamide at 1 and 2 years, the numbers needed to treat to achieve one additional patient with chemotherapy-naïve metastatic castration-resistant prostate cancer with progression-free survival were 2.0 and 2.8, respectively; with radiographic progression-free survival, 2.6 and 3.0, respectively; and without prostate-specific antigen progression, 1.8 and 2.4, respectively. Using TERRAIN data (n = 184 enzalutamide; n = 191 bicalutamide) comparing enzalutamide with bicalutamide at 1 and 2 years, the numbers needed to treat to achieve one additional patient with progression-free survival were 4.3 and 3.7, respectively; with radiographic progression-free survival, 10.0 and 2.8, respectively; and without prostate-specific antigen progression, 2.1 and 3.2, respectively.

CONCLUSIONS

The combined data from TERRAIN and STRIVE demonstrated that treating chemotherapy-naïve metastatic castration-resistant prostate cancer with enzalutamide leads to more patients without clinical progression at 1 and 2 years than with bicalutamide.

TRIAL REGISTRATION

STRIVE (NCT01664923; registration date: August 10, 2012) and TERRAIN (NCT01288911; registration date: February 1, 2011).

Patterns of Bicalutamide Use in Prostate Cancer Treatment: A U.S. Real-World Analysis Using the SEER-Medicare Database

Introduction

Bicalutamide (BIC), a non-steroidal anti-androgen, is FDA-indicated for use in combination with a luteinizing hormone-releasing hormone (LHRH) analog for treatment of Stage D2 metastatic carcinoma of the prostate. Lack of consensus exists regarding the clinical benefit of BIC use, either alone or combined use of BIC with an LHRH analog or antagonist (combined androgen blockade or CAB), versus treatment with androgen deprivation therapy (ADT) alone.

Methods

The SEER-Medicare database was used to identify prostate cancer patients aged ≥ 66 years diagnosed between 2007 and 2011 and who filled at least one prescription for BIC. Duration of BIC treatment was assessed in relation to ADT use; either alone (monotherapy), as part of CAB only, and as part of CAB followed by monotherapy. Additionally, we assessed use of BIC during or outside a potential testosterone flare prevention period (initiation within 2 months of an LHRH agonist).

Results

A total of 7521 prostate cancer patients who filled a prescription for BIC were identified. Eighteen percent of the cohort used BIC alone, over half the patients (54%) used BIC as part of CAB and 27% used BIC as part of CAB followed by monotherapy. Among men treated with BIC as part of CAB, 58% received BIC only within the potential flare period.

Conclusions

Although there is no FDA indication for BIC use as monotherapy, > 44% of patients in this study used BIC alone or as part of CAB followed by monotherapy. Further research is necessary to understand the outcomes of BIC utilization in these settings, particularly compared with newer second-generation anti-androgens.

Funding

Medivation LLC, a Pfizer company, and Astellas, Pharma, Inc.

Electronic supplementary material

The online version of this article (10.1007/s12325-018-0738-5) contains supplementary material, which is available to authorized users.

Correlation of Prostate Cancer CHD1 Status with Response to Androgen Deprivation Therapy: a Pilot Study

INTRODUCTION

CHD1 has been identified as a tumor suppressor gene in prostate cancer. Previous studies have shown strong associations between CHD1 deletion, prostate specific antigen [PSA] recurrence, and absence of ERG fusion. In this preliminary study we seek to find whether there is an independent correlation between CHD1 status and response to androgen deprivation therapy[ADT].

MATERIALS AND METHODS

We identified 11 patients with prostate cancer who underwent prostatectomy and received at least 7 months of ADT at our institution. They were divided into undetectable [PSA < 0.2 ng/mL; n = 8] and detectable [PSA > 0.2 ng/mL; n = 3] according to their serum PSA nadir after 7 months of ADT. Tissue microarray was generated from their formalin-fixed paraffin-embedded prostatectomy and involved lymph node tissues. Fluorescence in situ hybridization [FISH] analysis for CHD1 and immunohistochemical stains for PSA, AR, PTEN, ERG and SPINK1 were performed.

RESULTS

Our results showed heterogeneity of FISH and immunostains expressions in different foci of tumor. Status of CHD1, ERG, PTEN, or SPINK1 did not correlate with one another or with response to ADT.

CONCLUSIONS

Additional larger studies may be needed to further elucidate trends between these biomarkers and clinical outcomes in prostate cancer patients.

223Ra-Dichloride in castration-resistant metastatic prostate cancer: improving outcomes and identifying predictors of survival in clinical practice

Purpose

We first assessed whether the pattern of referrals to a nuclear medicine clinic improved as experience with ²²³Ra-dichloride increased, and whether referral patterns affected patient outcomes, and second assessed the value of bone scintigraphy, total alkaline phosphatase (tALP) and lymphadenopathy as prognostic factors in patients receiving ²²³Ra-dichloride.

Methods

A total of 57 patients eligible to receive ²²³Ra-dichloride over a 2-year period (March 2014 to March 2016) were retrospectively assessed and prospectively followed (median follow up 298 days). ²²³Ra-Dichloride was administered at 4-week intervals for a maximum of six injections. The numbers of patients in years 1 and 2 referred in relation to extent of bone disease (EOBD) category and overall survival (OS) were determined. The prognostic factors EOBD category, baseline tALP (tALP_BL), tALP response, greatest percentage reduction in tALP from baseline in any treatment cycle (ALP_max; among patients with elevated ALP_BL), and the presence of lymphadenopathy were assessed as predictors of OS.

Results

The proportion of patients with EOBD1 was higher in year 2 than in year 1 (29% and 4%, respectively), and in year 2 there was a lower rate of symptomatic skeleton-related events, a higher proportion of patients completing six cycles, and longer (albeit nonsignificant) OS (p = 0.55). There were significant differences in OS between EOBD4 patients and those in all other groups and between EOBD1 and EOBD3 patients (p < 0.05). OS was longer in patients with normal tALP_BL than in those with elevated tALP_BL (p = 0.01), in ALP responders than in nonresponders (p < 0.05), and in patients without lymphadenopathy than in those with lymphadenopathy (p = 0.29). OS was correlated with ALP_max (r² = 0.24).

Conclusion

A collaborative multidisciplinary referrals pathway, together with increased experience with ²²³Ra-dichloride, led to improved outcomes. In patients with elevated tALP_BL, tALP dynamics may be useful for monitoring response and predicting OS. Imaging and prognostic markers may therefore be of value for individualizing ²²³Ra-dichloride treatment and planning retreatment; however, further studies are required.

Patient-reported outcomes for patients with metastatic castration-resistant prostate cancer receiving docetaxel and Atrasentan versus docetaxel and placebo in a randomized phase III clinical trial (SWOG S0421)

Background

SWOG S0421 was a large randomized trial comparing docetaxel/prednisone plus placebo (DPP) to docetaxel/prednisone plus atrasentan over 12 cycles for patients with metastatic castration-resistant prostate cancer (mCRPC). The current report presents the PRO results for this trial, an important secondary endpoint.

Methods

The trial specified two primary PRO endpoints. Palliation of worst pain was based on the Brief Pain Inventory (BPI), where a 2 point difference is defined as clinically meaningful. Improvement of functional status was based on the Functional Assessment of Cancer Therapy – Prostate Cancer Trial Outcome Index (FACT-P TOI); a 5-point difference has been defined as clinically meaningful. We compared rates by arm using chi-square tests. Longitudinal analyses using linear mixed models addressed changes by arm over time.

Results

Four-hundred eighty-nine patients on each arm were evaluable for PRO endpoint data. There were no differences by arm in clinically meaningful pain palliation (41.7% for DPP vs. 44.0% for DPA, p = .70) or functional status (24.2% for DPP vs. 28.7% for DPA, p = .13). Longitudinal comparisons indicated no differences over time by arm for BPI Worst Pain scores (0.13 points, p = .23). Patients on the DPA arm had improved functional status of 1.78 points on average, a statistically significant (p = .02) but not clinically meaningful difference.

Conclusions

The SWOG S0421 PRO data showed little evidence of clinically meaningful differences by arm in either pain palliation or functional status.

Electronic supplementary material

The online version of this article (10.1186/s41687-018-0054-5) contains supplementary material, which is available to authorized users.

Optimizing Anticancer Therapy in Metastatic Non-Castrate Prostate Cancer: American Society of Clinical Oncology Clinical Practice Guideline

Purpose

This clinical practice guideline addresses abiraterone or docetaxel with androgen-deprivation therapy (ADT) for metastatic prostate cancer that has not been treated (or has been minimally treated) with testosterone-lowering agents.

Methods

Standard therapy for newly diagnosed metastatic prostate cancer has been ADT alone. Three studies have compared ADT alone with ADT and docetaxel, and two studies have compared ADT alone with ADT and abiraterone.

Results

Three prospective randomized studies (GETUG-AFU 15, STAMPEDE, and CHAARTED) examined overall survival (OS) with adding docetaxel to ADT. STAMPEDE and CHAARTED favored docetaxel (hazard ratio [HR], 0.78; 95% CI, 0.66 to 0.93; n = 2,962 and HR, 0.73; 95% CI, 0.59 to 0.89; n = 790, respectively). GETUG-AFU 15 was negative. LATITUDE and STAMPEDE examined the impact on OS of adding abiraterone (with prednisone or prednisolone) to ADT. LATITUDE and STAMPEDE favored abiraterone (HR, 0.62; 95% CI, 0.51 to 0.76; n = 1,199 and HR, 0.63; 95% CI, 0.52 to 0.76; n = 1,917, respectively).

Recommendations

ADT plus docetaxel or abiraterone in newly diagnosed metastatic non-castrate prostate cancer offers a survival benefit as compared with ADT alone. The strongest evidence of benefit with docetaxel is in men with de novo high-volume (CHAARTED criteria) metastatic disease. Similar survival benefits are seen using abiraterone acetate in high-risk patients (LATITUDE criteria) and in the metastatic population in STAMPEDE. ADT plus abiraterone and ADT plus docetaxel have not been compared, and it is not known if some men benefit more from one regimen as opposed to the other. Fitness for chemotherapy, patient comorbidities, toxicity profiles, quality of life, drug availability, and cost should be considered in this decision. Additional information is available at www.asco.org/genitourinary-cancer-guidelines .

Symptom assessment to guide treatment selection and determine progression in metastatic castration-resistant prostate cancer: Expert opinion and review of the evidence

Multiple new agents to treat metastatic castration-resistant prostate cancer (mCRPC) have become available in recent years; however, the appropriate timing and sequencing of these agents have yet to be elucidated. Until accurate biomarkers become available to allow more focused therapeutic targeting for this population, treatment selection for men with mCRPC will continue to be driven largely by close assessment of patient-related factors and symptoms. Pain, as the predominant symptom of mCRPC, is often the focus when assessing progression and the need for a change in treatment. A myriad of other symptoms, including fatigue, impact on activities of daily living, sleep, and lower urinary tract symptoms, also affect men with mCRPC, and assessment of the composite of these symptoms provides an earlier signal for the need to adjust treatment. A number of tools are available for assessing symptoms in patients with advanced prostate cancer, but they are not routinely used, given their complexity and length. A new simplified questionnaire is proposed for the assessment of symptoms, beyond pain, to inform treatment decisions for men with mCRPC.

Intermittent vs continuous docetaxel therapy in patients with metastatic castration-resistant prostate cancer - a phase III study (PRINCE)

OBJECTIVE

To investigate non-inferiority of intermittent docetaxel compared to continuous docetaxel in patients with metastatic castration-resistant prostate cancer (mCRPC).

PATIENT AND METHODS

The investigator initiated randomised phase III study included 187 chemotherapy-naïve patients with mCRPC who were allocated to two treatment arms: intermittent docetaxel and continuous docetaxel. Docetaxel was applied in both arms as weekly (35 mg/m² ) or 3-weekly (75 mg/m² ). The primary endpoint was 1-year survival, which was tested for non-inferiority (margin δ = 0.125). The secondary endpoints were: overall survival (OS), progression-free survival (PFS), median time to treatment failure (TTF), and toxicity.

RESULTS

Of 156 eligible patients, 78 were allocated to each arm. The intermittent treatment met the non-inferiority criteria for 1-year survival (two-sided 95% confidence interval, -0.12, 18, P = 0.022), but not for OS, according to the result of a post hoc analysis. The differences between the study arms in PFS and TTF were not significant. The median (range) treatment holiday in the intermittent arm was 110 (13-486) days, or 38% of the overall treatment duration. Safety profiles of both study arms were comparable. The main limitation of this study was that the planned number of patients could not be recruited.

CONCLUSION

Intermittent docetaxel chemotherapy was non-inferior to continuous therapy for 1-year survival; non-inferiority in regard to OS was not reached.

Temporal and geographic variation in the systemic treatment of advanced prostate cancer

BACKGROUND

Several systemic treatments have been shown to increase survival for patients with metastatic castration-resistant prostate cancer. This study sought to characterize variation in use of the six "focus drugs" (docetaxel, abiraterone, enzalutamide, sipuleucel-T, radium-223, and cabazitaxel) that have been approved by the Food and Drug Administration for the treatment of metastatic castration-resistant prostate cancer during the years 2010-2015. We hypothesized that the use of these treatments would vary over time and by region of the country.

METHODS

We used Clinformatics DataMart™ Database (OptumInsight, Eden Prairie, MN), a de-identified claims database from a national insurance provider. Our sample included patients with prostate cancer who received any of the six drugs. We describe changes in usage patterns over time and geographic region of the United States via detailed descriptive statistics. We explore both patterns of first line therapy and sequence of treatments in our database.

RESULTS

Our final analysis included 4275 patients with a mean age of 74 years. Docetaxel was the most commonly used first-line therapy in 2010 (97%), 2011 (66%), and 2012 (49%). Abiraterone was the most commonly used first-line therapy in 2013 (56%), 2014 (46%), and 2015 (34%). Approximately 14% of our study cohort received ≥3 of the 6 drugs throughout their disease course. There was marked geographic variation in use of each of the drugs.

CONCLUSION

Variation in treatment patterns were found with respect to both time and geographic location. Prescription rates of abiraterone outpaced docetaxel as the most commonly prescribed drug after 2013 when it became widely available. However, some regions of the country still lagged behind and prescribed less than would be expected.

Phase I Trial of the Combination of Docetaxel, Prednisone, and Pasireotide in Metastatic Castrate-Resistant Prostate Cancer

BACKGROUND

Pasireotide (SOM230; Novartis Inc, Basel, Switzerland) is a multitargeted somatostatin receptor analogue likely to treat the neuroendocrine, and docetaxel resistant components within metastatic castrate-resistant prostate cancer (mCRPC). This phase I trial tested the combination of pasireotide, docetaxel, and prednisone in pretreated mCRPC.

PATIENTS AND METHODS

Chemotherapy naive mCRPC patients received docetaxel 75 mg/m² intravenously every 21 days and pasireotide intramuscularly every 28 days at escalating dose levels of 40, 60, and 80 mg. Maximum tolerated dose and recommended phase II dose (RP2D) were assessed.

RESULTS

Eighteen patients were enrolled with a median age of 65 (range, 49-75) years, and pretherapy prostate-specific antigen of 259.9 ng/mL. The dose-limiting toxicities were Grade 4 hyperglycemia unresponsive to therapy and Grade 4 neutropenia lasting for > 7 days in 1 patient each occurring at the 80-mg dose level of pasireotide. The RP2D was determined at 60 mg every 28 days. Four patients at the 60 mg dose had Grade 3 or 4 hyperglycemia, which responded adequately to therapy. Median time to progression and survival were 7.2 and 18.3 months, respectively. Three of 6 patients with circulating tumor cells ≥5 converted to circulating tumor cells < 5 post therapy. The insulin like growth factor-1 levels revealed a median 51% decrease after therapy. The neuron-specific enolase and chromogranin did not show any marked change.

CONCLUSION

The addition of pasireotide to docetaxel and prednisone is clinically feasible at a dose level of 60 mg every 28 days. The combination showed potential for clinical efficacy but needs to be compared with the standard docetaxel and prednisone regimen.

Treatment dynamics of bone-targeting agents among men with bone metastases from prostate cancer in the United States

PURPOSE

To examine the dynamics of treatment with 2 bone-targeting agents (BTAs)-denosumab and zoledronic acid-among men with bone metastases from prostate cancer.

METHODS

Using electronic health record data from oncology practices across the US, we identified prostate cancer patients diagnosed with bone metastasis in 2012/2013 without evidence of BTA use within 6 months prior to diagnosis. We examined the risk and predictors of BTA initiation, interruption, and re-initiation.

RESULTS

Among 897 men diagnosed with prostate cancer, the cumulative incidence of BTA initiation after bone metastasis diagnosis was 34% (95% confidence interval [CI], 31-37%) at 30 days, 64% (95% CI, 61-68%) at 180 days, and 88% (95% CI, 85-91%) at 2 years. Denosumab was initiated more frequently than zoledronic acid. Men with diabetes, more bone lesions, history of androgen deprivation therapy, or no hospice enrollment were more likely to initiate treatment. Following initiation, the cumulative incidence of treatment interruption was 17% (95% CI, 14-19%) at 60 days and 70% (95% CI, 66-74%) at 2 years, with interruption more likely among patients receiving emerging therapies for prostate cancer or enrolling in hospice. The cumulative incidence of re-initiation following interruption was 36.3% (95% CI, 32.7-40.2%) at 15 days, 49.8% (95% CI, 45.9-54.1%) at 30 days, and 81.0% (95% CI, 77.5-84.7%) at 1 year.

CONCLUSIONS

Bone-targeting agent therapy is initiated by the majority of men living with bone metastases following a prostate cancer diagnosis; however, the timing of initiation is highly variable. Once on treatment, gaps or interruptions in therapy are common.

Association analysis of SNPs present in plasma with adverse events and population pharmacokinetics in Chinese sunitinib treated patients with renal cell carcinoma

Background

Sunitinib is a tyrosine kinase inhibitor with effective therapeutic outcomes in patients with renal-cell carcinoma. The study were to analyze the association of single-nucleotide polymorphisms present in cell-free DNA and pharmacokinetics with sunitinib treatment-emergent adverse events in Chinese patients with renal-cell carcinoma.

Materials and Methods

We genotyped 8 keys SNPs in 6 candidate genes. The plasma concentrations of sunitinib and N-desethyl sunitinib were measured using a high performance liquid chromatography-tandam mass spectrometry method. Correlations between the single-nucleotide polymorphisms and adverse events were investigated by univariate and multivariate logistic regression and we quantitatively evaluated the effect of single-nucleotide polymorphisms on the pharmacokinetics of sunitinib by using a population PK model.

Results

Necessary dose reductions of sunitinib were significantly correlated with SNP rs1933437 in FLT3. A higher severity of AEs were collected with SNP rs2032582 in ABCB1 and rs1800812 in PDGFRα. Thrombocytopenia was collected with rs1800812 in PDGFRα. Our study provides a population PK model of sunitinib with the ABCB1 genotype as a predictive covariate for apparent oral clearance.

Conclusions

Our study preliminarily confirmed the hypothesis that the pharmacokinetics of sunitinib is affected by the SNPs of enzyme in Chinese renal-cell carcinoma patients, and this affects the different distribution and severity of adverse events of sunitinib.

Current approaches to incorporation of radium-223 in clinical practice

Background

Treatment options for metastatic castration-resistant prostate cancer (mCRPC) have expanded in recent years and include cytotoxic agents (e.g., docetaxel and cabazitaxel), immunotherapy (e.g., sipuleucel-T), oral hormonal therapies targeting the androgen receptor axis (e.g., enzalutamide and abiraterone), and targeted alpha therapy (e.g., radium-223 dichloride (radium-223)). Although treatment guidelines have been updated to reflect the availability of new agents, it is not easy to apply them in daily clinical practice because recommendations vary depending on patient comorbidities and disease characteristics. Furthermore, therapeutic accessibility, clinical judgment, and experience affect the selection of treatment options.

Methods

In this review, we provide practical guidance for the integration of radium-223 into the management of patients with mCRPC based on our collective clinical experience, as well as the available clinical trial data.

Results

Radium-223 is a targeted alpha therapy; as a bone-seeking calcium mimetic, it accumulates in hydroxyapatite areas surrounding tumor lesions and selectively binds to the areas of increased bone turnover. Radium-223 prolongs overall survival and delays time to the first symptomatic skeletal events in men with mCRPC, and is indicated for the treatment of patients with CRPC, symptomatic bone metastases, and no known visceral metastases. We review its clinical efficacy and safety, practical guidance on identifying the appropriate patient, and recommendations for how best to educate and inform prospective patients regarding their treatment decision making. In addition, we review recent evidence for sequential and combination therapies with radium-223, provide our experiences with these treatment approaches, and discuss their implications for the future treatment of patients with mCRPC.

Conclusions

Based on our clinical experience, radium-223 should be considered relatively early in the treatment course in patients with mCRPC with bone metastases. Coordination of care among multidisciplinary team members, patients, and caregivers is essential for optimizing safe and effective treatment with all CRPC therapies.

Treatments for Metastatic Prostate Cancer (mPC): A Review of Costing Evidence

BACKGROUND

Prostate cancer (PC) is the most common cancer in Western countries. More than one third of PC patients develop metastatic disease, and the 5-year expected survival in distant disease is about 35%. During the last few years, new treatments have been launched for metastatic castrate-resistant prostate cancer (mCRPC).

OBJECTIVES

We aimed to review the current literature on health economic analysis on the treatment of metastatic prostate cancer (mPC), compare the studies, summarize the findings and make the results available to administrators and decision makers.

METHODS

A systematic literature search was done for economic evaluations (cost-minimization, cost-effectiveness, cost-utility, cost-of-illness, cost-of-drug, and cost-benefit analyses). We employed the PubMed^® search engine and searched for publications published between 2012 and 2016. The terms used were "prostate cancer", "metastatic" and "cost". An initial screening of all headlines was performed, selected abstracts were analysed, and finally the full papers investigated. Study characteristics, treatment and comparator, country, type of evaluation, perspective, year of value, time horizon, efficacy data, discount rate, total costs and sensitivity analysis were analysed. The quality was assessed using the Quality of Health Economic Studies (QHES) instrument.

RESULTS

A total of 227 publications were detected and screened, 58 selected for full-text assessment and 31 included in the final analyses. Despite the significant international literature on the treatment of mCRPC, there were only 15 studies focusing on cost-effectiveness analysis (CEA). Medical treatment constituted two thirds of the selected studies. Significant costs in the treatment of mCRPC were disclosed. In the pre-docetaxel setting, both abiraterone acetate (AA) and enzalutamide were concluded beyond accepted cost/quality-adjusted life year limits. In the docetaxel refractory setting, most studies concluded that enzalutamide was cost-effective and superior to AA. In most studies, cabazitaxel was not recommended, because of high cost. Looking at bone-targeting drugs, generic zoledronic acid (ZA) was recommended. External beam radiotherapy (EBRT) was analysed in three studies, and single fraction radiotherapy was concluded to be cost saving. Radium-223 was documented as beneficial, but costly. The quality of the studies was generally good, but sensitivity analyses, discounting and the measurement of health outcomes were present in less than two thirds of the selected studies.

CONCLUSIONS

The treatment of mCRPC was associated with significant cost. In the post-docetaxel setting, single fraction radiotherapy and enzalutamide were considered cost-effective in most studies. Generic ZA was the recommended bone-targeting therapy.

Optimal usage of radium-223 in metastatic castration-resistant prostate cancer

Radium-223 is a first-in-class α-emitting radiopharmaceutical that targets bone metastases associated with metastatic castration-resistant prostate cancer (mCRPC). In the pivotal phase III trial ALSYMPCA, radium-223 significantly increased overall survival (OS), compared with placebo (median 14.9 vs 11.3 months; hazard ratio 0.70; 95% CI 0.58-0.83; p < 0.001), in patients with mCRPC and symptomatic bone metastases-with a comparable safety profile. To optimize treatment outcomes, selection of appropriate patients is important. As well as osteoblastic bone metastases, mCRPC patients should be well enough to receive six doses of radium-223 as this treatment duration has been shown to greatly improve OS outcomes compared with administration of four or fewer doses. Additionally, alkaline phosphatase and lactate dehydrogenase are emerging as important biomarkers during radium-223 treatment. Optimal concomitant standard-of-care therapies (such as abiraterone or enzalutamide) to be administered with radium-223 have yet to be defined as does the most efficacious dose and duration of radium-223 treatment. In conclusion, radium-223 is an important addition to the mCRPC treatment landscape and marks a paradigm shift in the treatment of bone metastases.

Phase 2 Study of Weekly Paclitaxel Plus Estramustine in Metastatic Hormone-Refractory Prostate Carcinoma: ECOG-ACRIN Cancer Research Group (E1898) Trial

INTRODUCTION

This multicenter phase 2 study assessed the combination of estramustine and weekly paclitaxel with metastatic castration-resistant prostate cancer (CRPC).

PATIENTS AND METHODS

We enrolled 77 patients who had received no prior chemotherapy for CRPC between 1998 and 2000; a total of 74 subjects were eligible for the study. Each 8-week cycle included paclitaxel 90 mg/m² provided intravenously weekly for 6 weeks, followed by 2 weeks off therapy and oral estramustine 280 mg twice daily for 3 days beginning 24 hours before the first dose of paclitaxel. The primary end point was rate of objective or prostate-specific antigen (PSA) response at 16 weeks. A 50% response rate was considered of further interest.

RESULTS

Eligible patients received a median of 3 cycles (range, 1-10 cycles). The response rate among patients with measurable disease was 34% (95% confidence interval [CI], 19-52). The PSA response rate was 58% (95% CI, 47-70). Clinical benefit rate was 45% (95% CI, 33-57). The median progression-free survival was 5.9 months (95% CI, 4.4-6.7). The median overall survival was 17.6 months (95% CI, 14.6-20.8). The most common clinical grade 3/4 toxicities were fatigue (14%) and sensory neuropathy (7%). Grade 3/4 hematologic toxicities included lymphopenia (21%) and anemia (9%). There was one toxicity-related death. Quality-of-life scores improved by week 8, but the change was not statistically significant.

CONCLUSION

The combination has activity defined by PSA declines in CRPC but did not meet the protocol-specified end point for efficacy as defined by objective response rate. Since this study was conducted, more effective, better-tolerated regimens have been developed.

Aggressive End-of-Life Care for Metastatic Cancer Patients Younger Than Age 65 Years

Background

Aggressive medical care at the end of life can be harmful to patients and families, but its prevalence in use among younger cancer patients is unknown. The goal of the study was to report on the use of aggressive care and hospice services for patients younger than age 65 years.

Methods

Using the HealthCore Integrated Research Database, we analyzed patients who died between 2007 and 2014 with metastatic lung (n = 12 764), colorectal (n = 5207), breast (n = 5855), pancreatic (n = 3397), or prostate (n = 1508) cancer. Based on published quality measures, we assessed uses of chemotherapy, intensive care, emergency room visits, and hospice care at the end of life. We examined additional items including radiotherapy, invasive procedures, hospitalization, and in-hospital deaths. Multivariable modified Poisson regression models were used to adjust for age, sex, geographic region, rural/urban location, year of death, and regional education and income measures.

Results

Across the five cancers, 10.1% to 14.1% of patients received chemotherapy within the last 14 days of life, 15.9% to 20.6% received intensive care in last 30 days, and 1.5% to 2.5% went to the emergency room two or more times in last 30 days. Hospice enrollment at least three days before death was 54.4% to 59.6%. However, 55.3% to 59.3% of patients had a hospital admission in the last 30 days, and one-third died (30.3%-35.4%) in the hospital.

Conclusions

There was low use of cancer-directed treatment at the end of life for younger cancer patients, and hospice use was higher than 50%. However, there was a relatively high utilization of hospital-based care. These results demonstrate an opportunity for continued improvements in the provision of high-value, patient-centered care at the end of life.

Insulin-Like Growth Factor (IGF) Pathway Targeting in Cancer: Role of the IGF Axis and Opportunities for Future Combination Studies

Despite a strong preclinical rationale for targeting the insulin-like growth factor (IGF) axis in cancer, clinical studies of IGF-1 receptor (IGF-1R)-targeted monotherapies have been largely disappointing, and any potential success has been limited by the lack of validated predictive biomarkers for patient enrichment. A large body of preclinical evidence suggests that the key role of the IGF axis in cancer is in driving treatment resistance, via general proliferative/survival mechanisms, interactions with other mitogenic signaling networks, and class-specific mechanisms such as DNA damage repair. Consequently, combining IGF-targeted agents with standard cytotoxic agents, other targeted agents, endocrine therapies, or immunotherapies represents an attractive therapeutic approach. Anti-IGF-1R monoclonal antibodies (mAbs) do not inhibit IGF ligand 2 (IGF-2) activation of the insulin receptor isoform-A (INSR-A), which may limit their anti-proliferative activity. In addition, due to their lack of specificity, IGF-1R tyrosine kinase inhibitors are associated with hyperglycemia as a result of interference with signaling through the classical metabolic INSR-B isoform; this may preclude their use at clinically effective doses. Conversely, IGF-1/IGF-2 ligand-neutralizing mAbs inhibit proliferative/anti-apoptotic signaling via IGF-1R and INSR-A, without compromising the metabolic function of INSR-B. Therefore, combination regimens that include these agents may be more efficacious and tolerable versus IGF-1R-targeted combinations. Herein, we review the preclinical and clinical experience with IGF-targeted therapies to-date, and discuss the rationale for future combination approaches as a means to overcome treatment resistance.

Practical recommendations for radium-223 treatment of metastatic castration-resistant prostate cancer

PURPOSE

Radium Ra 223 dichloride (radium-223, Xofigo®) is the first targeted alpha therapy for patients with castration-resistant prostate cancer and symptomatic bone metastases. Radium-223 provides a new treatment option for this setting, but also necessitates a new treatment management approach. We provide straightforward and practical recommendations for European nuclear medicine centres to optimize radium-223 service provision.

METHODS

An independent research consultancy agency observed radium-223 procedures and conducted interviews with all key staff members involved in radium-223 treatment delivery in 11 nuclear medicine centres across six countries (Germany, Italy, the Netherlands, Spain, Switzerland and the UK) experienced in administering radium-223. The findings were collated and discussed at a meeting of experts from these centres, during which key consensus recommendations were defined.

RESULTS

The recommendations cover centre organization and preparation; patient referral; radium-223 ordering, preparation and disposal; radium-223 treatment delivery/administration; and patient experience. Guidance includes structured coordination and communication within centres and multidisciplinary teams, focusing on sharing best practice to provide high-quality, patient-centred care throughout the treatment pathway.

CONCLUSIONS

These expert recommendations are intended to complement existing management guidelines. Sharing best practice and experience will help nuclear medicine centres to optimize radium-223 service provision and improve patient care.

Efficacy and Safety of Enzalutamide vs Bicalutamide in Younger and Older Patients with Metastatic Castration Resistant Prostate Cancer in the TERRAIN Trial

PURPOSE

Enzalutamide significantly prolonged median progression-free survival vs bicalutamide in chemotherapy naïve men with metastatic castration resistant prostate cancer in the TERRAIN (Enzalutamide versus Bicalutamide in Castrate Men with Metastatic Prostate Cancer) trial. In this post hoc analysis we investigated the influence of age on the efficacy and safety of enzalutamide vs bicalutamide in this population.

MATERIALS AND METHODS

Patients were randomized 1:1 to enzalutamide 160 mg per day or bicalutamide 50 mg per day. Progression-free survival, time to prostate specific antigen progression and safety were analyzed post hoc in younger (age less than 75 years) and older (age 75 years or greater) subgroups.

RESULTS

Enzalutamide significantly reduced the risk of disease progression or death vs bicalutamide in patients younger than 75 years (HR 0.38, 95% CI 0.27-0.52, p <0.0001) and 75 years old or older (HR 0.59, 95% CI 0.37-0.92, p = 0.018). Time to prostate specific antigen progression was also significantly prolonged with enzalutamide vs bicalutamide in each subgroup. The adverse event distribution between treatments was similar in each subgroup except for more (5% or greater difference between subgroups) atrial fibrillation, urinary tract infections, falls and decreased appetite as well as less extremity pain and hot flushing in enzalutamide treated patients 75 years old or older, and less back pain and hot flushing in bicalutamide treated patients 75 years old or older. Grade 3 or greater cardiac events were more frequent in enzalutamide treated and bicalutamide treated patients who were 75 years old or older vs younger than 75 years. Fatigue was more frequent in enzalutamide treated patients with a similar distribution in each age subgroup.

CONCLUSIONS

Enzalutamide improved clinical outcomes vs bicalutamide irrespective of age. Increased falls and cardiac events suggest caution when prescribing to older patients (age 75 years or greater) with significant comorbidity.

Hematologic Toxicity of Concurrent Administration of Radium-223 and Next-generation Antiandrogen Therapies

PURPOSE/OBJECTIVES

Radium-223 is a first-in-class radiopharmaceutical recently approved for the treatment of castration-resistant prostate cancer in patients with symptomatic bone metastases. Initial studies investigating Radium-223 primarily used nonsteroidal first-generation antiandrogens. Since that time, newer antiandrogen therapies have demonstrated improved survival in patients with castration-resistant prostate cancer. It has been suggested that the rational combination of these newly approved agents with Radium-223 may lead to improved response rates and clinical outcomes. Currently, there is lack of information regarding the safety of concurrent administration of these agents with radiopharmaceuticals. Here, we report on hematologic toxicity findings from our institution in patients receiving concurrent Radium-223 and next-generation antiandrogen therapies with either enzalutamide or abiraterone.

MATERIALS/METHODS

In a retrospective study, we analyzed patients who received Radium-223 as part of an early-access trial, and following FDA approval in May 2013, patients receiving Radium-223 as part of standard care. Radium-223 was given at standard dosing of 50 kBq/kg each month for 6 total cycles. Complete blood counts were performed before treatment monthly and following each injection. Blood counts from patients receiving Radium alone and concurrently with next-generation antiandrogens were compared. To date, 25 total patients were analyzed, with a median of 5 monthly doses received per patient. Fourteen patients received concurrent therapy during monthly Radium-223 with either enzalutamide (n=8) or abiraterone (n=6).

RESULTS

Six patients expired due to disease progression. Two patients discontinued treatment due to grade 3 myelosuppression. For patients receiving either Radium alone and with concurrent next-generation antiandrogen therapy, there did not appear to be any statistically significant differences between initial and nadir blood counts. Mean change from initial neutrophil count to nadir was 1.9×10/L in patients receiving Radium alone, versus 2.3×10/L in patients receiving concurrent therapy (P=0.77). Mean change from initial hemoglobin value to nadir was 1.5 g/L in patients receiving Radium alone, versus 1.8 g/L in patients receiving concurrent therapy (P=0.31). Mean change from initial platelet count to nadir was 52.3×10 cells/L in patients receiving Radium alone versus 70.6×10 cells/L in patients receiving concurrent therapy (P=0.39). Individual blood counts for each measured laboratory are included in the supplemental data. PSA was stable or decreased in 22% of patients receiving Radium alone versus 35% of patients receiving combination treatment (P=0.24).

CONCLUSIONS

Concurrent administration of Radium-223 and next-generation antiandrogen therapies appears to be well tolerated with similar toxicities to standard administration of Radium-223 alone. This particular cohort of patients represents a high-risk, heavily pretreated group of patients with advanced metastatic disease and significant marrow burden. Despite these risk factors, hematologic toxicity was modest and was in the range expected for this risk group based on previous trials. To date, this is the first study investigating the toxicity of combination treatment. Further studies investigating the safety and efficacy of combination treatments are warranted.

Predicting Response and Recognizing Resistance: Improving Outcomes in Patients With Castration-resistant Prostate Cancer

Optimal sequencing strategies for approved agents in metastatic castration-resistant prostate cancer (mCRPC) are unclear. Retrospective clinical studies suggest cross-resistance between specific therapies. This review assesses treatment decisions for mCRPC. Increased use of chemohormonal therapy in castration-sensitive disease may affect subsequent treatment decisions in mCRPC. Initial abiraterone or enzalutamide treatment may result in cross-resistance for subsequent androgen receptor-targeted therapy. Clinical responses may be seen in both docetaxel- and cabazitaxel-treated patients progressing after treatment with abiraterone or enzalutamide. These observations are supported by proposed resistance mechanisms. In conclusion, small, retrospective studies suggest cross-resistance between specific therapies in mCRPC. Larger prospective studies are required.

Early National Dissemination of Abiraterone and Enzalutamide for Advanced Prostate Cancer in Medicare Part D

INTRODUCTION

Abiraterone and enzalutamide were approved by the Food and Drug Administration in 2011 and 2012 to treat men with metastatic castration-resistant prostate cancer (mCRPC). Most men with mCRPC are > 65 years of age and thus eligible for Medicare Part D. We conducted a study to better understand the early dissemination of these drugs across the United States using national Medicare Part D data.

METHODS

We evaluated the number of prescriptions for abiraterone and enzalutamide by provider specialty and hospital referral region (HRR) using Medicare Part D and Dartmouth Atlas data. We categorized HRRs by abiraterone and enzalutamide prescriptions, adjusted for prostate cancer incidence, and examined factors associated with regional variation using multilevel regression models.

RESULTS

Among providers who wrote the majority of prescriptions for abiraterone or enzalutamide in 2013 (n = 2,121), 87.5% were medical oncologists, 3.3% were urologists, and 9.2% were other provider specialties. Among prescribers, approximately 30% were responsible for three quarters of the claims for abiraterone and 20% were responsible for more than half the claims for enzalutamide. Some HRRs demonstrated low-prescribing rates despite average medical oncology and urology physician workforce density. Our multilevel model demonstrated that regional factors potentially influenced variation in care.

CONCLUSION

The majority of prescriptions written for abiraterone and enzalutamide through Medicare Part D in 2013 were written by a minority of providers, with marked regional variation across the United States. Better understanding of the early national dissemination of these effective but expensive drugs can help inform strategies to optimize introduction of new, evidence-based mCRPC treatments.

Safety and Efficacy of Docetaxel, Bevacizumab, and Everolimus for Castration-resistant Prostate Cancer (CRPC)

BACKGROUND

Previous data suggests that co-targeting mammalian target of rapamycin and angiogenic pathways may potentiate effects of cytotoxic chemotherapy. We studied combining mammalian target of rapamycin and vascular endothelial growth factor inhibition with docetaxel in castrate-resistant prostate cancer (CRPC).

METHODS

Eligible patients had progressive, metastatic, chemotherapy-naive CRPC. Docetaxel and bevacizumab were given intravenously day 1 with everolimus orally daily on a 21-day cycle across 3 dose levels (75:15:2.5, 75:15:5, and 65:15:5; docetaxel mg/m2, mg/kg bevacizumab, and mg everolimus, respectively). Maintenance therapy with bevacizumab/everolimus without docetaxel was allowed after ≥ 6 cycles.

RESULTS

Forty-three subjects were treated across all dose levels. Maximal tolerated doses for the combined therapies observed in the phase 1B portion of the trial were: docetaxel 75 mg/m2, bevacizumab 15 mg/kg, and everolimus 2.5 mg. Maximal prostate-specific antigen decline ≥ 30% and ≥ 50% was achieved in 33 (79%) and 31 (74%) of patients, respectively. Best response by modified Response Evaluation Criteria In Solid Tumors criteria in 25 subjects with measurable disease at baseline included complete or partial response in 20 (80%) patients. The median progression-free and overall survival were 8.9 months (95% confidence interval, 7.4-10.6 months) and 21.9 months (95% confidence interval, 18.4-30.3 months), respectively. Hematologic toxicities were the most common treatment-related grade ≥ 3 adverse events including: febrile neutropenia (12; 28%), lymphopenia (12; 28%), leukocytes (10; 23%), neutrophils (9; 21%), and hemoglobin (2; 5%). Nonhematologic grade ≥ 3 adverse events included: hypertension (8; 19%), fatigue (3; 7%), pneumonia (3; 7%), and mucositis (4; 5%). There was 1 treatment-related death owing to neutropenic fever and pneumonia in a patient treated at dose level 3 despite dose modifications and prophylactic growth factor support.

CONCLUSIONS

Docetaxel, bevacizumab, and everolimus can be safely administered in CRPC and demonstrate a significant level of anticancer activity, meeting the predetermined response criteria. However, any potential benefit of combined therapy must be balanced against increased risk for toxicities. Our results do not support the hypothesis that this combination of agents improves upon the results obtained with docetaxel monotherapy in an unselected population of chemotherapy-naive patients with CRPC.

Radium-223 dichloride for the treatment of castration-resistant prostate cancer with symptomatic bone metastases

INTRODUCTION

Castration-resistant prostate cancer (CRPC) is associated with the development of bone metastases, increased mortality, and a reduction in the patient's quality of life (QOL). The management of metastatic CRPC (mCRPC) has rapidly evolved over the past decade, with a number of available therapeutic agents improving overall survival. Radium-223 dichloride (radium-223), the first targeted alpha therapy, improves survival accompanied by QOL benefits with a favorable safety profile. It is approved in over 40 countries for the treatment of patients with CRPC with symptomatic bone metastases and no known visceral metastatic disease. Areas covered: The current management of CRPC in men with bone metastases, and in particular the role of radium-223 in this setting, is reviewed and discussed. A search of bibliographic databases for peer-reviewed literature and major meetings was conducted. Expert commentary: In treating patients with mCRPC, the best sequencing and/or combination of radium-223 with other agents has yet to be fully elucidated. The role of radium-223 in treating patients with hormone-sensitive metastatic prostate cancer who are candidates for chemotherapy should also be investigated in well-designed trials. The ability to tailor radium-223 therapy to both the clinical and genetic profiles of CRPC patients would be a promising development.

PSMA-Based Radioligand Therapy for Metastatic Castration-Resistant Prostate Cancer: The Bad Berka Experience Since 2013

A potential milestone in personalized nuclear medicine is theranostics of metastatic castration-resistant prostate cancer (mCRPC) based on molecular imaging using PET/CT with ⁶⁸Ga-labeled prostate-specific membrane antigen (PSMA) ligands and molecular radiotherapy using PSMA-targeted radioligand therapy (PRLT) with ¹⁷⁷Lu-PSMA ligands. ⁶⁸Ga-PSMA PET/CT enables accurate detection of mCRPC lesions with high diagnostic sensitivity and specificity and provides quantitative and reproducible data that can be used to select patients for PRLT and therapeutic monitoring. Our comprehensive experience over the last 3 years using different radioligands indicates that PRLT is highly effective for the treatment of mCRPC, even in advanced cases, and potentially lends a significant benefit to overall and progression-free survival. Additionally, significant improvement in clinical symptoms and excellent palliation of pain can be achieved.