Cost-effectiveness of enzalutamide versus apalutamide versus androgen deprivation therapy alone for the treatment of metastatic castration-sensitive prostate cancer in Canada

The association between polypharmacy and health-related quality of life among older adults with prostate cancer

INTRODUCTION

Older adults with prostate cancer (PC) are at risk of polypharmacy, which further complicates disease management and health-related quality of life (HRQoL). This study evaluated the association between polypharmacy and HRQoL among Medicare beneficiaries with PC.

MATERIALS AND METHODS

This observational, retrospective study analyzed data from the Surveillance, Epidemiology, and End Results (SEER) Medicare Health Outcomes Survey (MHOS) data resource. Beneficiaries aged ≥65 and enrolled in Medicare Advantage Organizations were included if they had a PC diagnosis and continuously enrolled in Part D for 12 months prior to the completion of MHOS. Polypharmacy was determined based on the unique number of concurrent Part D prescriptions during 12 months before survey: no polypharmacy (NP, n = 0-4), polypharmacy (PP, n = 5-9), and excessive polypharmacy (EPP, n ≥ 10). HRQoL was assessed using the Physical and Mental Component Summary T-scores (PCS and MCS, respectively) in MHOS. ANOVA and Pearson's Chi-Square tests were performed to assess variances between polypharmacy and continuous/categorical variables. Multivariate linear regression models with generalized estimating equations were used to assess the association between polypharmacy and HRQoL. The severely impaired HRQoL cohort was identified based on normalized z-scores of PCS and MCS. Odds ratios were calculated to prioritize drug-drug and class-class pairs associated with patients with severely impaired HRQoL.

RESULTS

Data from 16,573 beneficiaries (24,126 records) showed that 44.4% had PP and 10.1% had EPP. Beneficiaries with PP and EPP had significantly lower mean PCS and MCS scores compared to those without polypharmacy (p < 0.001). After adjusting for covariates, beneficiaries with EPP had clinically significantly lower PCS (adjusted marginal difference: -8.47 [-9.00, -7.94]) and MCS (adjusted marginal difference: -4.32 [-4.89, -3.75]) compared to the NP group. Top-ranked drug-drug pairs like tiotropium bromide and oxycodone/acetaminophen exhibited significant associations with HRQoL decline. Analysis of class-class pairs highlighted (1) corticosteroid hormone receptor agonists and opioid agonists and (2) benzodiazepines and adrenergic beta2-agonists as having significant associations with HRQoL decline.

DISCUSSION

Polypharmacy exhibits a significant association with HRQoL declines among older adults with PC.

Cost-Effectiveness Analysis of Systemic Therapy for Intensification of Treatment in Metastatic Hormone-Sensitive Prostate Cancer in India

BACKGROUND AND OBJECTIVE

Androgen-deprivation therapy is the mainstay of treatment for patients with newly diagnosed metastatic hormone-sensitive prostate cancer (mHSPC). However, the intensification of treatment with either docetaxel or novel anti-androgens (abiraterone-acetate plus prednisone [AAP], enzalutamide, and apalutamide) is being recommended based on the improved clinical outcomes and quality of life among patients. This study aimed to determine the most cost-effective drug for treatment intensification for patients with mHSPC in India.

METHODS

A Markov model was developed with four health states: progression-free survival, progressive disease, best supportive care, and death. Lifetime costs and consequences were estimated for four treatment sequences: AAP-first, enzalutamide-first, apalutamide-first, and docetaxel-first. Incremental cost per quality-adjusted life-year (QALY) gained with a given treatment option was compared against the next best alternative and assessed for cost effectiveness using a willingness to pay threshold of 1 × per capita gross domestic product in India.

RESULTS

We estimated that the total lifetime cost per patient was ₹1,367,454 (US$17,487), ₹2,168,885 (US$27,735), ₹7,678,501 (US$98,190), and ₹1,358,746 (US$17,375) in the AAP-first, enzalutamide-first, apalutamide-first, and docetaxel-first treatment sequence, respectively. The mean quality-adjusted life-years lived per patient were 4.78, 5.03, 3.22, and 2.61, respectively. The AAP-first sequence incurs an incremental cost of ₹4014 (US$51) per quality-adjusted life-year gained as compared with the docetaxel-first sequence, with a 87% probability of being cost effective at the willingness-to-pay threshold of 1 × per-capita gross domestic product of India. The use of AAP-first also incurs an incremental net monetary benefit of ₹396,491 (US$5070) as compared with the docetaxel-first treatment sequence. Nearly a 48% reduction in the price of enzalutamide is required to make it a cost-effective treatment sequence as compared with AAP-first in India.

CONCLUSIONS

We concur with the inclusion of standard-dose AAP in India's publicly financed health insurance scheme for the intensification of treatment in mHSPC as it is the only cost-effective sequence among the various novel anti-androgens when compared with the docetaxel-first treatment sequence. Furthermore, a systematic reduction in the price of enzalutamide would further help to improve clinical outcomes among patients with mHSPC.

Cost-effectiveness analysis of 7 treatments in metastatic hormone-sensitive prostate cancer: a public-payer perspective

BACKGROUND

Recently, several new treatment regimens have been approved for treating metastatic hormone-sensitive prostate cancer, building on androgen deprivation therapy alone. These include docetaxel androgen deprivation therapy, abiraterone acetate-prednisone androgen deprivation therapy, apalutamide androgen deprivation therapy, enzalutamide androgen deprivation therapy, darolutamide-docetaxel androgen deprivation therapy, and abiraterone-prednisone androgen deprivation therapy with docetaxel. There are no validated predictive biomarkers for choosing a specific regimen. The goal of this study was to conduct a health economic outcome evaluation to determine the optimal treatment from the US public sector (Veterans Affairs).

METHODS

We developed a partitioned survival model in which metastatic hormone-sensitive prostate cancer patients transitioned between 3 health states (progression free, progressive disease to castrate resistance state, and death) at monthly intervals based on Weibull survival model estimated from published Kaplan-Meier curves using a Bayesian network meta-analysis of 7 clinical trials (7208 patients). The effectiveness outcome in our model was quality-adjusted life-years (QALYs). Cost input parameters included initial and subsequent treatment costs and costs for terminal care and for managing grade 3 or higher drug-related adverse events and were obtained from the Federal Supply Schedule and published literature.

RESULTS

Average 10-year costs ranged from $34 349 (androgen deprivation therapy) to $658 928 (darolutamide-docetaxel androgen deprivation therapy) and mean QALYs ranged from 3.25 (androgen deprivation therapy) to 4.57 (enzalutamide androgen deprivation therapy). Treatment strategies docetaxel androgen deprivation therapy, enzalutamide androgen deprivation therapy docetaxel, apalutamide androgen deprivation therapy, and darolutamide-docetaxel androgen deprivation therapy were eliminated because of dominance (ie, they were more costly and less effective than other strategies). Of the remaining strategies, abiraterone acetate-prednisone androgen deprivation therapy was the most cost-effective strategy at a willingness-to-pay threshold of $100 000/QALY (incremental cost-effectiveness ratios = $21 247/QALY).

CONCLUSIONS

Our simulation model found abiraterone acetate-prednisone androgen deprivation therapy to be an optimal first-line treatment for metastatic hormone-sensitive prostate cancer from a public (Veterans Affairs) payer perspective.