Resource utilization and use of life-extending therapies and corticosteroids in prostate cancer patients with corticosteroid-sensitive comorbidities

The rates of septicemia in older adults with prostate cancer treated with abiraterone or enzalutamide: A population-based study

INTRODUCTION

Prostate cancer (PCa) is the most common non-cutaneous tumor among American men. Androgen receptor signaling inhibitors such as abiraterone and enzalutamide have been approved for similar disease states among patients with advanced PCa. Existing data suggest using steroids is associated with an increased risk of infection. Because abiraterone is usually prescribed with prednisone, we sought to compare the risk of septicemia in patients using abiraterone vs. enzalutamide.

MATERIALS AND METHODS

We utilized the SEER-Medicare-linked data and used negative binomial regression models to compare the changes in the rates of septicemia-related hospitalizations six months pre- and post-abiraterone and enzalutamide initiation.

RESULTS

We found that the incidence of septicemia-related hospitalizations increased 2.77 fold within six months of initiating abiraterone (incidence rate ratio [IRR]: 2.77, 95% confidence interval [CI]: 2.17-3.53) 1.97 fold within six months of starting enzalutamide (IRR: 1.97, 95% CI: 1.43-2.72). However, the difference in the changes did not reach statistical significance (interaction IRR: 0.71, 95% CI: 0.48-1.06).

DISCUSSION

The findings suggest that both abiraterone and enzalutamide are associated with an increased risk of septicemia-related hospitalizations. However, the difference in the increase of septicemia risk following the two treatments did not reach statistical significance. Further studies are warranted to understand the mechanisms at play.

A pharmacoeconomic evaluation of pharmaceutical treatment options for prostate cancer

INTRODUCTION

Prostate cancer is one of the most common neoplasms in men. For many years the mainstay of treatment was androgen deprivation therapy, but during last decade many novel agents have emerged, accompanied by increased costs for healthcare systems.

AREAS COVERED

In this literature review, the authors provide a pharmacoeconomic review of several pharmaceutical agents used in several disease stages, by summarizing evidence from cost-analysis, cost-effectiveness, cost-utility, cost-saving, cost-benefit and budgetary impact analysis studies.

EXPERT OPINION

The rapid development of therapeutic agents for prostate cancer has put a great budgetary burden on healthcare systems, since these drugs are prolonging survival and improving quality of life . Since existing data are now mature enough from a number of clinical trials with long-term follow-up, policy makers should propose not only the most clinically effective but also the most cost-effective agents, in order for every patient to gain access at least to some of these therapies. Docetaxel addition seems to be a cost-effective option, when compared to both abiraterone and enzalutamide (due to costs related to acquisition and side effects). Cabazitaxel is a strong candidate after docetaxel failure, while both denosumab and bisphosphonates are cost-effective for reducing skeletal-related events in metastatic disease.

Economic Outcomes in Patients with Chemotherapy-Naïve Metastatic Castration-Resistant Prostate Cancer Treated with Enzalutamide or Abiraterone Acetate Plus Prednisone

Introduction

Prostate cancer (PC) is the second leading cause of cancer death among US men and accounts for considerable healthcare expenditures. We evaluated economic outcomes in men with chemotherapy-naïve metastatic castration-resistant PC (mCRPC) treated with enzalutamide or abiraterone acetate plus prednisone (abiraterone).

Methods

We performed a retrospective analysis on 3174 men (18 years or older) utilizing the Veterans Health Administration (VHA) database from 1 April 2014 to 31 March 2018. Men with mCRPC were included if they had at least one pharmacy claim for enzalutamide or abiraterone (first claim date = index date) following surgical or medical castration, had no chemotherapy treatment within 12 months prior to the index date, and had continuous VHA enrollment for at least 12 months pre- and post-index date. Men were followed until death, disenrollment, or end of study and were 1:1 propensity score matched (PSM). All-cause and PC-related resource use and costs per patient per month (PPPM) in the 12 months post index were compared between matched cohorts.

Results

We identified 1229 men with mCRPC prescribed enzalutamide and 1945 prescribed abiraterone with mean ages of 74 and 73 years, respectively. After PSM, each cohort had 1160 patients. The enzalutamide cohort had fewer all-cause (2.51 vs 2.86; p < 0.0001) and PC-related outpatient visits (0.86 vs 1.03; p < 0.0001), with corresponding lower all-cause ($2588 vs $3115; p < 0.0001) and PC-related ($1356 vs $1775; p < 0.0001) PPPM outpatient costs compared with the abiraterone cohort. All-cause total costs (medical and pharmacy) PPPM ($8085 vs $9092; p = 0.0002) and PC-related total costs PPPM ($6321 vs $7280; p < 0.0001) were significantly lower in the enzalutamide cohort compared with the abiraterone cohort.

Conclusions

Enzalutamide-treated men with chemotherapy-naïve mCRPC had significantly lower resource utilization and healthcare costs compared with abiraterone-treated men.

Electronic Supplementary Material

The online version of this article (10.1007/s12325-020-01260-x) contains supplementary material, which is available to authorized users.

Prostate cancer (PC) is the second leading cause of death among men with cancer in the USA. Healthcare costs associated with PC, including hospitalizations, outpatient visits, and medications prescribed to treat adverse effects, depend on the severity of the disease and intensity of treatment, but are generally very high. Enzalutamide and abiraterone acetate with prednisone (abiraterone) are both approved treatments for men with PC that does not respond to treatments that reduce the male hormone testosterone, known as castration-resistant PC (CRPC). These drugs are associated with varying treatment duration and different adverse effects, and therefore could result in differences in the use of healthcare resources and overall cost of treatment. Here we evaluated the healthcare resource utilization (HCRU), which was calculated as the average number of healthcare encounters, including inpatient stays, outpatient visits, and pharmacy visits, and length of inpatient stays, and treatment costs associated with use of enzalutamide or abiraterone by men with metastatic CRPC (mCRPC), who had not received prior chemotherapy in the Veterans Health Administration. We found that men with chemotherapy-naïve mCRPC treated with enzalutamide used less healthcare resources and incurred lower total healthcare costs than men treated with abiraterone. On average, all-cause total healthcare costs were $1007 per patient per month lower and PC-related total healthcare costs were $959 per patient per month lower for patients treated with enzalutamide than those treated with abiraterone. These results support the hypothesis that the long-term HCRU and costs of enzalutamide may be lower compared with abiraterone.

Adverse Events Associated with Cumulative Corticosteroid Use in Patients with Castration-Resistant Prostate Cancer: An Administrative Claims Analysis

INTRODUCTION

Corticosteroids are a mainstay treatment for castration-resistant prostate cancer (CRPC). Although corticosteroids have been associated with adverse events, long-term outcomes related to their sustained use have not been assessed in men with CRPC.

OBJECTIVE

This study evaluated the impact of cumulative corticosteroid exposure on the risk of developing specific adverse events in men with CRPC.

METHODS

Data were obtained from administrative claims databases. Adult chemotherapy-naïve men who initiated CRPC treatment following surgical or medical castration were selected. Patients were grouped into four cohorts based on cumulative corticosteroid dose: no exposure, low exposure (< 0.5 g), medium exposure (0.5-2.0 g), and high exposure (> 2.0 g). Time to each adverse event was assessed using Kaplan-Meier analyses and time-dependent Cox proportional hazard models, adjusting for baseline characteristics.

RESULTS

Overall, 9425 patients were included (no exposure, N = 6765; low exposure, N = 1660; medium exposure, N = 655; high exposure, N = 345). The mean age was 71-76 years across cohorts. During the study period, cumulative corticosteroid exposure was associated with a significantly higher risk of developing an infection [high vs. no exposure, adjusted hazard ratio (HR) 2.55; 95% confidence interval (CI) 2.27-2.85; p < 0.001 for trend], peptic ulcer (HR 1.91; 95% CI 1.39-2.64; p < 0.001), acute cardiovascular events (HR 1.62; 95% CI 1.43-1.83; p < 0.001), endocrine disorder (HR 1.61; 95% CI 1.34-1.94; p < 0.001), fracture (HR 1.59; 95% CI 1.37-1.86; p < 0.001), or mental health condition (HR 1.28; 95% CI 1.06-1.55; p = 0.014). Exposure to corticosteroids was associated with a more rapid onset of adverse events.

CONCLUSION

Patients with CRPC receiving corticosteroids had a higher risk of developing a wide range of adverse events than those not receiving them. The increased adverse event risk was observed after accounting, to the extent possible, for patients' overall disease severity.

Health Care Resource Utilization and Costs Associated with Corticosteroid Use in Patients with Castration-Resistant Prostate Cancer: An Administrative Claims Analysis

BACKGROUND

Corticosteroids are used in the management of castration-resistant prostate cancer (CRPC) to reduce tumor-related symptoms because of CRPC therapies. Since corticosteroids have been associated with a range of toxicities, their use may increase the economic burden sustained by patients with CRPC. However, the economic impact of using corticosteroids in patients with CRPC has not been well characterized.

OBJECTIVE

To assess the effect of previous corticosteroid use on health care resource utilization (HRU) and health care costs among men with CRPC.

METHODS

Using administrative claims data (2007-2016), adult chemotherapy-naive patients who initiated CRPC treatment following surgical or medical castration were identified. Based on the cumulative corticosteroid dose during the 12 months before CRPC treatment initiation, patients were grouped into 4 cohorts: no corticosteroid (0 gm), low corticosteroid (< 0.5 gm), medium corticosteroid (0.5-2.0 gm), and high corticosteroid (> 2.0 gm). All-cause HRU and costs (2017 U.S. dollars) were compared between cohorts during the 1-year study period following CRPC treatment initiation using the no corticosteroid cohort as reference. Multivariable regression models were used to adjust for baseline covariates, including age, region, index year, Charlson Comorbidity Index score, presence of bone metastases, baseline all-cause HRU, and corticosteroid-related clinical events during baseline.

RESULTS

9,425 patients were included (no corticosteroid = 6,765, low corticosteroid = 1,660, medium corticosteroid = 655, and high corticosteroid = 345). On average, patients in the no corticosteroid cohort were older and had a lower baseline HRU and comorbidity burden than patients in the other 3 cohorts. During the study period, patients with corticosteroid exposure (across all corticosteroid cohorts) had significantly more inpatient admissions (high corticosteroid vs. no corticosteroid adjusted incidence rate ratio [IRR] = 1.56; P < 0.001), emergency department visits (high corticosteroid vs. no corticosteroid adjusted IRR = 1.30; P = 0.001), and outpatient visits (high corticosteroid vs. no corticosteroid adjusted IRR = 1.11; P < 0.001). In addition, compared with the no corticosteroid cohort, patients with corticosteroid exposure had significantly higher monthly total costs (high corticosteroid vs. no corticosteroid adjusted difference = $2,600; P < 0.001), including medical service costs (high corticosteroid vs. no corticosteroid adjusted difference = $1,564; P < 0.001) and pharmacy costs (high corticosteroid vs. no corticosteroid adjusted difference = $825; P < 0.001).

CONCLUSIONS

Cumulative corticosteroid exposure before CRPC treatment initiation was associated with significantly higher HRU and costs. This increase in economic burden was more prominent among patients with annual cumulative corticosteroid doses of more than 2.0 gm. These results suggest that previous corticosteroid use may result in a higher economic burden among patients with CRPC.

DISCLOSURES

This study was funded by Astellas Pharma (Northbrook, IL) and Medivation, a Pfizer Company (San Francisco, CA), the codevelopers of enzalutamide. The study sponsor was involved in the study design, data interpretation, and review. All authors contributed to the development of the manuscript and maintained control over the final content. Schultz and Wilson are employed by Astellas Pharma. Schultz owns stock in Gilead Sciences and Shire. Song and Yang are employed by Analysis Group, which received consultancy fees from Astellas Pharma. Ramaswamy is employed by Pfizer, and Lowentritt is employed by Chesapeake Urology and has served as a speaker and consultant for Astellas Pharma, Pfizer, Bayer, Dendreon, and Janssen. A synopsis of the current research was presented in poster format at the AMCP Managed Care & Specialty Pharmacy Annual Meeting 2019, which took place in San Diego, CA, on March 25-28, 2019.

Cost-effectiveness analyses and cost analyses in castration-resistant prostate cancer: A systematic review

Background

Treatment of metastatic prostate cancer is associated with high personal and economic burden. Recently, new treatment options for castration-resistant prostate cancer became available with promising survival advantages. However, cost-effectiveness of those new treatment options is sometimes ambiguous or given only under certain circumstances. The aim of this study was to systematically review studies on the cost-effectiveness of treatments and costs of castration-resistant prostate cancer (CRPC) and metastasizing castration-resistant prostate cancer (mCRPC) on their methodological quality and the risk of bias.

Methods

A systematic literature search was performed in the databases PubMed, CINAHL Complete, the Cochrane Library and Web of Science Core Collection for costs-effectiveness analyses, model-based economic evaluations, cost-of-illness analyses and budget impact analyses. Reported costs were inflated to 2015 US$ purchasing power parities. Quality assessment and risk of bias assessment was performed using the Consolidated Health Economic Evaluation Reporting Standards checklist and the Bias in Economic Evaluations checklist, respectively.

Results

In total, 38 articles were identified by the systematic literature search. The methodological quality of the included studies varied widely, and there was considerable risk of bias. The cost-effectiveness treatments for CRPC and mCRPC was assessed with incremental cost-effectiveness ratios ranging from dominance for mitoxantrone to $562,328 per quality-adjusted life year gained for sipuleucel-T compared with prednisone alone. Annual costs for the treatment of castration-resistant prostate cancer ranged from $3,067 to $77,725.

Conclusion

The cost-effectiveness of treatments of CRPC strongly depended on the willingness to pay per quality-adjusted life year gained/life-year saved throughout all included costs-effectiveness analyses and model-based economic evaluations. High-quality cost-effectiveness analyses based on randomized controlled trials are needed in order to make informed decisions on the management of castration-resistant prostate cancer and the resulting financial impact on the healthcare system.

Treatment Duration, Healthcare Resource Utilization, and Costs Among Chemotherapy-Naïve Patients with Metastatic Castration-Resistant Prostate Cancer Treated with Enzalutamide or Abiraterone Acetate: A Retrospective Claims Analysis

Introduction

Enzalutamide and abiraterone acetate (plus prednisone) are new hormonal treatments for metastatic castration-resistant prostate cancer (mCRPC). This study compared treatment duration, healthcare resource utilization (HRU), and treatment costs for chemotherapy-naïve mCRPC patients treated with enzalutamide or abiraterone acetate in the USA.

Methods

Chemotherapy-naïve mCRPC patients initiating treatment with enzalutamide or abiraterone acetate were identified from administrative claims. Continuous enrollment ≥ 6 months before and ≥ 3 months after the index date (initiation date of enzalutamide or abiraterone acetate) was required. Treatment duration, all-cause and prostate cancer-related HRU, and costs were estimated during the post-index period. Multivariable analyses compared HRU and costs between cohorts, adjusting for baseline characteristics.

Results

Overall, 920 chemotherapy-naïve patients initiated enzalutamide and 2310 initiated abiraterone acetate (median follow-up, 10.7 and 13.5 months, respectively). More enzalutamide-treated patients had corticosteroid-sensitive comorbidities at baseline. Treatment duration was longer with enzalutamide versus abiraterone acetate (median, 10.7 vs. 8.8 months; P = 0.008). Enzalutamide was associated with fewer all-cause inpatient admissions [adjusted incidence rate ratio (95% confidence interval) 0.87 (0.76, 0.99)], days of hospitalization [0.84 (0.70, 1.02)], and outpatient visits [0.94 (0.90, 0.98)], and fewer prostate cancer-related outpatient visits [0.92 (0.87, 0.96)] compared with abiraterone acetate. Enzalutamide was also associated with lower prostate cancer-related inpatient and emergency department costs [adjusted differences, $122 (P = 0.024) and $28 (P = 0.009), respectively].

Conclusion

Chemotherapy-naïve mCRPC patients treated with enzalutamide versus abiraterone acetate had longer treatment duration and incurred lower HRU and prostate cancer-related inpatient and emergency department costs.

Funding

Astellas Pharma Inc.

Electronic supplementary material

The online version of this article (10.1007/s12325-018-0774-1) contains supplementary material, which is available to authorized users.