Clinicopathologic factors that influence prognosis and survival outcomes in men with metastatic castration-resistant prostate cancer treated with Radium-223

The prognostic value of Eastern Cooperative Oncology Group performance status on overall survival among patients with metastatic prostate cancer: a systematic review and meta-analysis

Background

There is heterogeneity in the literature regarding the strength of association between Eastern Cooperative Oncology Group performance status (ECOG PS) and mortality. We conducted a systematic review and meta-analysis of studies reporting the prognostic value of ECOG PS on overall survival (OS) in metastatic prostate cancer (mPC).

Methods

PubMed was searched from inception to March 21, 2022. A meta-analysis pooling the effect of ECOG PS categories (≥2 vs. <2, 2 vs. <2, and ≥1 vs. <1) on OS was performed separately for studies including patients with metastatic castration-resistant prostate cancer (mCRPC) and metastatic castration-sensitive prostate cancer (mCSPC) using a random-effects model. Analyses were stratified by prior chemotherapy and study type.

Results

Overall, 75 studies, comprising 32,298 patients, were included. Most studies (72/75) included patients with mCRPC. Higher ECOG PS was associated with a significant increase in mortality risk, with the highest estimate observed among patients with mCRPC with an ECOG PS of ≥2 versus <2 (hazard ratio [HR]: 2.10, 95% confidence interval [CI]: 1.87-2.37). When stratifying by study type, there was a higher risk estimate of mortality among patients with mCRPC with an ECOG PS of ≥1 versus <1 in real-world data studies (HR: 1.98, 95% CI: 1.72-2.26) compared with clinical trials (HR: 1.32, 95% CI: 1.13-1.54; p < 0.001). There were no significant differences in the HR of OS stratified by previous chemotherapy.

Conclusion

ECOG PS was a significant predictor of OS regardless of category, previous chemotherapy, and mPC population. Additional studies are needed to better characterize the effect of ECOG PS on OS in mCSPC.

Low Alanine Aminotransferase, as a Marker of Sarcopenia and Frailty, Is Associated with Shorter Survival Among Prostate Cancer Patients and Survivors. A Retrospective Cohort Analysis of 4064 Patients

Background

Sarcopenia is characterized by loss of muscle mass and function and is associated with frailty, a syndrome with higher likelihood of falls, fractures, physical disability, and mortality. Both frailty and sarcopenia are known markers of shorter survival in various cancer patient populations. Low alanine aminotransferase (ALT), reflecting loss of muscle mass (sarcopenia), may be associated with greater frailty and shorter survival in multiple cancers.

Objective

To assess the potential association between low ALT and shorter survival among prostate cancer (PCa) patients and survivors.

Design setting and participants

This was a retrospective analysis of a historical cohort of PCa patients and survivors. Patients were defined as those still actively receiving PCa treatment, while those no longer receiving such treatment were classified as PCa survivors.

Outcome measurements and statistical analysis

ALT data were obtained from results for basic biochemical blood testing carried out for patients on their first hospital admission. Patients were divided into two groups: those with ALT ≥17 IU/l and those with ALT <17 IU/l. Univariate and multivariable analyses were conducted for between-group survival comparisons.

Results and limitations

We identified 9489 PCa records. The final study cohort with ALT data available included 4064 patients with ALT <40 IU/l. Of this cohort, 536 patients were actively receiving medical anticancer therapy for PCa. The mean age for the entire cohort was 74.6 yr (standard deviation 9.6) and the median ALT level was 19.28 IU/l; 1676 patients (41%) had low ALT (<17 IU/l). On univariate analysis, low ALT was associated with a 78% increase in mortality risk (95% confidence interval [CI] 1.62-1.97; p < 0.001). A sensitivity analysis of the 536 patients actively receiving medical anticancer treatment revealed that low ALT was associated with a 48% increase in mortality risk (95% CI 1.19-1.85; p = 0.001). In a multivariable model controlled for age, kidney disease, history of cerebrovascular event/transient ischemic attack, and baseline prostate-specific antigen, low ALT was still associated with a 35% increase in mortality risk (95% CI 1.12-1.63; p = 0.001). Limitations include the single-center, retrospective design.

Conclusions

Low ALT, which is indicative of sarcopenia and frailty, is associated with shorter survival among PCa patients and survivors and could potentially be used for treatment personalization.

Patient summary

We compared survival for prostate cancer patients and survivors according to their blood level of the protein alanine aminotransferase (ALT). Low ALT levels in the general population are associated with loss of muscle mass. We found that in our group of prostate cancer patients and survivors, the risk of death from any cause was higher for those with low ALT levels.

Real-world effectiveness, long-term safety and treatment pathway integration of radium-223 therapy in patients with metastatic castration-resistant prostate cancer

Radium-223 dichloride (²²³Ra) is an α-emitter approved for the treatment of metastatic castration-resistant prostate cancer (mCRPC) with bone metastases, but without visceral involvement. Despite being a life-prolonging therapy (LPT), ²²³Ra remains underutilized. A large body of real-world evidence (RWE) for ²²³Ra has been published in the decade since the pivotal phase 3 ALSYMPCA study, a period during which the treatment landscape has continued to evolve. How to optimize ²²³Ra use, including how to integrate it into the mCRPC management pathway amongst other current LPTs (i.e., with respect to timing and concurrent, layered, or sequential use), is therefore of considerable interest. RWE studies lack the conventional restraints of clinical trials and can therefore help to build an understanding of how treatments may be best used in routine practice. Here we review RWE studies investigating the efficacy and safety of ²²³Ra in mCRPC [including in sequence with the recently approved 177-Lutetium conjugated to the ligand prostate-specific membrane antigen (¹⁷⁷Lu-PSMA)], as well as response marker development, imaging techniques, and current clinical practice recommendations.

Lutetium Lu 177 vipivotide tetraxetan for metastatic castration-resistant prostate cancer

INTRODUCTION

¹⁷⁷Lu-vipivotide tetraxetan is a radiopharmaceutical that selectively targets prostate-specific membrane antigen (PSMA) and delivers beta-radiations to kill prostate cancer cells.

AREAS COVERED

Extensive experience outside the United States as well as randomized phase II and phase III data demonstrate that ¹⁷⁷Lu-vipivotide tetraxetan is a safe, generally well tolerated, and effective therapy for men with mCRPC. ¹⁷⁷Lu-vipivotide tetraxetan was approved by the FDA in March 2022 for the treatment of PSMA-positive metastatic castration-resistant prostate cancer (mCRPC) after androgen receptor pathway inhibition and taxane-based chemotherapy based on the results of the VISION trial.

EXPERT OPINION

This review discusses the development and studies leading to the approval of ¹⁷⁷Lu-vipivotide tetraxetan. In all, ¹⁷⁷Lu-vipivotide tetraxetan is an exciting new tool in the arsenal for men with mCRPC after novel androgen pathway inhibitors and at least one taxane chemotherapy. Optimal selection of patients, sequencing of ¹⁷⁷Lu-vipivotide tetraxetan with the other agents available to treat mCRPC, and the use of dosimetry are current areas of interest with great potential and opportunities for further individual patient optimization using the tools of theranostics.

Prognostic Value of the BIO-Ra Score in Metastatic Castration-Resistant Prostate Cancer Patients Treated with Radium-223 after the European Medicines Agency Restricted Use: Secondary Investigations of the Multicentric BIO-Ra Study

The multicentric retrospective BIO-Ra study combined inflammatory indices from peripheral blood and clinical factors in a composite prognostic score for metastatic castration-resistant prostate cancer patients receiving Radium-223 (Ra-223). In the present study, we evaluated (i) the prognostic power of the BIO-Ra score in the framework of the restricted use of Ra-223 promoted by the European Medicines Agency in 2018; (ii) the treatment completion prediction of the BIO-Ra score. Four hundred ninety-four patients from the BIO-Ra cohort were divided into three risk classes according to the BIO-Ra score to predict the treatment completion rate (p < 0.001 among all the three groups). Patients receiving Ra-223 after restriction (89/494) were at later stages of the disease compared with the pre-restriction cohort (405/494), as a higher percentage of BIO-Ra high-risk classes (46.1% vs. 34.6%) and lower median Overall survival (12.4 vs. 23.7 months, p < 0.001) was observed. Despite this clinically relevant difference, BIO-Ra classes still predicted divergent treatment completion rates in the post-restriction subgroup (72%, 52.2%, and 46.3% of patients belonging to low-, intermediate-, and high-risk classes, respectively). Although the restricted use has increased patients at higher risk with unfavourable outcome after Ra-223 treatment, the BIO-Ra score maintains its prognostic value.

Real-world patient characteristics associated with survival of 2 years or more after radium-223 treatment for metastatic castration-resistant prostate cancer (EPIX study)

Background

The real-world EPIX study was conducted to gather information about the characteristics of patients with metastatic castration-resistant prostate cancer (mCRPC) who survived ≥2 years after treatment with the alpha-emitter radium-223.

Methods

This retrospective study of electronic health records in the US Flatiron database (NCT04516161) included patients with mCRPC treated with radium-223 between January 2013 and June 2019. Median overall survival (OS) and prostate-specific antigen (PSA) response (≥50% reduction) from start of radium-223 treatment were the primary and secondary endpoints, respectively. Patient characteristics were compared between those who survived ≥2 years versus <2 years, including a subgroup who survived <6 months.

Results

In the 1180 patients identified, median OS was 12.9 months (95% CI: 12.1–13.7), and 13% of patients with data at 6 months had a PSA response. The survival groups included 775 patients (65.7%) who survived <2 years (including 264 (22.4%) who survived <6 months) and 185 patients (15.7%) who survived ≥2 years; 220 patients (18.6%) had incomplete follow-up data and were censored. On multivariate analysis, age >75 years, Eastern Cooperative Oncology Group performance status (ECOG PS) 2–4, visceral metastases, prior symptomatic skeletal events (SSEs), and prior chemotherapy were independently prognostic of reduced OS. For patients with survival ≥2 years versus <2 years, median age was 71 versus 75 years, 4% versus 14% had ECOG PS 2–4, 4% versus 10% had visceral metastases, 38% versus 44% had prior SSEs, and 16% versus 32% had prior chemotherapy.

Conclusions

In this study of men with mCRPC treated in real-world clinical practice, median OS was consistent with that seen in the phase 3 ALSYMPCA trial. Patients who survived ≥2 years after the start of radium-223 were younger and had better ECOG PS, lower disease burden, and less use of prior chemotherapy than those who survived <2 years.