Dataset Information

A real-world evaluation of radium-223 in combination with abiraterone or enzalutamide for the treatment of metastatic castration-resistant prostate cancer.

ABSTRACT:

Introduction

Radium-223, abiraterone, and enzalutamide have each been shown to significantly improve survival as monotherapy in patients with metastatic castration-resistant prostate cancer. However, effects of combination radium-223 plus abiraterone or enzalutamide on survival and safety remain unclear.

Patients and methods

This single-center retrospective cohort study used electronic health record data of patients with metastatic castration-resistant prostate cancer and bone metastases who were treated with radium-223 between April 1, 2014 and February 19, 2019. Patients who received radium-223 monotherapy were compared to patients who received a combination of radium-223 plus either abiraterone or enzalutamide. The primary endpoint was overall survival. Secondary endpoints included progression-free survival, time to symptomatic skeletal event, symptomatic skeletal event-free survival, and incidence of drug-related adverse events. Time-to-event analyses were estimated by log rank tests using Kaplan-Meier curves. Hazard ratios and 95% confidence intervals were derived from Cox proportional hazards models. Chi-square tests evaluated difference in serious adverse events between the two arms.

Results

A total of 60 patients met inclusion criteria (n = 41 in the monotherapy arm, n = 19 in the combination arm). Differences in median overall survival were not observed (12.7 vs. 12.8 months; HR 1.15, 95% CI 0.59-2.23; P = 0.68), but median progression-free survival was significantly longer in the combination arm (7.6 vs. 4.9 months; HR 1.94, 95% CI 1.11-3.40; P = 0.02). Significant differences were not observed in time to first SSE (P = 0.97), SSE-free survival (P = 0.16), or in the overall incidence of serious adverse events (P = 0.45).

Conclusion

Combination radium-223 plus abiraterone or enzalutamide did not improve overall survival, but prolonged progression-free survival without increasing the incidence of serious adverse events in metastatic castration-resistant prostate cancer patients with bone metastases. However, these results are limited by small numbers and patient selection inherent in retrospective analysis.

SUBMITTER: Kim SI

PROVIDER: S-EPMC8216516 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:ImportanceOlder adults are at greater risk of cognitive decline with various oncologic therapies. Some commonly used therapies for advanced prostate cancer, such as enzalutamide, have been linked to cognitive impairment, but published data are scarce, come from single-group studies, or focus on self-reported cognition.ObjectiveTo longitudinally examine the association between cognitive function and docetaxel (chemotherapy), abiraterone, enzalutamide, and radium Ra 223 dichloride (radium 223) in older men with metastatic castration-resistant prostate cancer.Design, setting, and participantsA multicenter, prospective, observational cohort study was conducted across 4 academic cancer centers in Ontario, Canada. A consecutive sample of 155 men age 65 years or older with metastatic castration-resistant prostate cancer starting any treatment with docetaxel, abiraterone acetate, enzalutamide, or radium Ra 223 dichloride (radium 223) were enrolled between July 1, 2015, and December 31, 2019.ExposuresFirst-line chemotherapy (docetaxel), abiraterone, enzalutamide, or radium 223.Main outcomes and measuresCognitive function was measured at baseline and end of treatment using the Montreal Cognitive Assessment, the Trail Making Test part A, and the Trail Making Test part B to assess global cognition, attention, and executive function, respectively. Absolute changes in scores over time were analyzed using univariate and multivariable linear regression, and the percentages of individuals with a decline of 1.5 SDs in each domain were calculated.ResultsA total of 155 men starting treatment with docetaxel (n = 51) (mean [SD] age, 73.5 [6.2] years; 34 [66.7%] with some postsecondary education), abiraterone (n = 29) (mean [SD] age, 76.2 [7.2] years; 18 [62.1%] with some postsecondary education), enzalutamide (n = 54) (mean [SD] age, 75.7 [7.4] years; 33 [61.1%] with some postsecondary education), and radium 223 (n = 21) (mean [SD] age, 76.4 [7.2] years; 17 [81.0%] with some postsecondary education) were included. Most patients had stable cognition or slight improvements during treatment. A cognitive decline of 1.5 SDs or more was observed in 0% to 6.5% of patients on each measure of cognitive function (eg, 3 of 46 patients [6.5%; 95% CI, 2.2%-17.5%] in the group receiving chemotherapy [docetaxel] had a decline of 1.5 SDs for Trails A and Trails B). Although patients taking enzalutamide had numerically larger declines than those taking abiraterone, differences were small and clinically unimportant.Conclusions and relevanceThese findings suggest that most older men do not experience significant cognitive decline in attention, executive function, and global cognition while undergoing treatment for advanced prostate cancer regardless of the treatment used.

Project description:BackgroundRadium-223 and enzalutamide are approved agents for patients with metastatic castration-resistant prostate cancer (mCRPC). Combining radium-223 and enzalutamide to improve outcomes is of clinical interest due to their differing modes of action and non-overlapping toxicity profiles.MethodsThis phase II study enrolled patients with mCRPC and bone metastases. Patients received six cycles of radium-223 in combination with enzalutamide, followed by enzalutamide alone. The primary endpoint was safety for the combination; secondary endpoints included radiographic/clinical progression-free survival (PFS), PSA PFS, overall survival (OS), change in alkaline phosphatase, patient-reported pain outcomes and skeletal related events.ResultsForty-five patients received the combination treatment: 42 patients (93.3%) received all six cycles. Fourteen patients (31.1%) developed grade 3 or 4 toxicities, most commonly fatigue and neutropaenia. Fractures during the combination period occurred in four patients (8.9%). A further 13 patients (28.9%) developed fractures after completing combination treatment, giving a total of 17 patients (37.8%) who developed a fracture at any time on study. The median time to fracture was greater than 17.2 months [95% confidence interval (CI), 17.2-not estimable]. The median time to PSA progression was 18.1 months (95% CI, 12.68-22.60) and the median time to radiological/clinical progression was 28.0 months (95% CI, 22.54-not reached). At the primary analysis, 19 (42.2%) out of 45 patients had died with a median OS not reached (mean 34.8 months, standard error 1.4).ConclusionIn men with progressive mCRPC and bone metastases, the combination of radium-223 and enzalutamide was tolerable with the majority of patients completing the combination treatment. Bone fractures during the combination period were uncommon; however, we did identify a higher incidence of fractures occurring in patients after completing combination treatment. Bone health agents should be administered and bone health should be closely monitored following treatment with radium-223 and enzalutamide.

Project description:BACKGROUND:It is hypothesised that cotargeting the androgen receptor (AR) and paracrine androgen biosynthesis with enzalutamide and abiraterone acetate in metastatic castration-resistant prostate cancer (mCRPC) will dissipate adaptive feedback loops observed with either agent alone. OBJECTIVE:To assess the safety, efficacy, androgen signalling/metabolome, and drug-drug interactions (DDIs) of enzalutamide with abiraterone acetate in progressive bone mCRPC (bmCRPC). DESIGN, SETTING, AND PARTICIPANTS:This open-label, single-centre interventional study was conducted in bmCRPC patients. INTERVENTION:Enzalutamide 160mg and abiraterone acetate 1000mg once daily; prednisone 5mg twice daily. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS:Adverse events (AEs), prostate-specific antigen (PSA) response, progression-free survival (PFS), tumour biomarker/metabolite expression, and Cmin plasma concentrations were evaluated. RESULTS AND LIMITATIONS:Sixty patients were enrolled. Common AEs independent of grade/causality included fatigue (72%), hyperglycaemia (67%), alkaline phosphatase (ALP) elevation (53%), and hot flush (43%). Grade 3 AEs included hypertension (17%), alanine aminotransferase elevation (12%), ALP elevation (5%), and arthralgia (5%). No treatment-related grade 4 AEs or deaths were reported. Median treatment-discontinuation time was 312d (95% confidence interval [CI] 196.0-483.0). Maximal PSA decline ?50% and ?90% occurred in 46 (77%) and 29 (48%) patients, respectively. Median PFS was 251d (95% CI 147-337). At week 9, median tumour microenvironment androgens, precursors, and nuclear AR expression decreased (p<0.001). The baseline tumour AR C/N terminal ratio of ?80% was associated with treatment benefit. At enzalutamide steady state, abiraterone acetate Cmin was ?23% lower (range 14.05-200.5ng/ml) than when given alone. CONCLUSIONS:Enzalutamide combined with abiraterone acetate has a manageable safety profile, without a meaningful DDI. Both agents are pharmacodynamically active with no feedback. Efficacy findings do not support significant benefit of combined treatment for unselected bmCRPC. PATIENT SUMMARY:This is the first study combining enzalutamide plus abiraterone in bone metastatic castration-resistant prostate cancer. Results show that this combination is safe.