Medication adherence among patients with advanced prostate cancer using oral therapies.

Aims: In light of the extended overall survival and improved quality of life provided by advanced prostate cancer (PC) oral therapies, this study aimed to describe treatment adherence to advanced PC oral therapies and evaluate associated patient characteristics and subsequent healthcare resource utilization (HRU). Patients & methods: Patients with advanced PC initiating apalutamide, enzalutamide or abiraterone acetate were identified from administrative data (October 1, 2014-September 30, 2019). Adherence and persistence at six months postinitiation were used to evaluate patient factors and HRU. Results: Aged ≥75 years, Black race, chemotherapy use and higher pharmacy paid amounts were associated with poor adherence/persistence, which translated to higher HRU. Conclusions: Strategies to increase adherence and persistence may improve patient outcomes and associated HRU.

Lay abstract This study included 27,262 patients with advanced prostate cancer who started taking one of three oral cancer medications (apalutamide, enzalutamide or abiraterone acetate) between October 2014 and September 2019. Patients who were black, aged 75 years or older, who had chemotherapy or who had higher prescription costs had the most difficulty following dosing guidelines or staying on treatment. Patients who did not follow dosing guidelines required more healthcare services. In light of the extended survival and improved quality of life that oral cancer medication for advanced prostate cancer provides, helping patients to take the correct medication dose, at the right time, and for the recommended length of time may improve their outcomes and reduce medical costs.

Cost-Effectiveness Assessment of Monitoring Abiraterone Levels in Metastatic Castration-Resistant Prostate Cancer Patients.

OBJECTIVES: Abiraterone acetate is registered for the treatment of metastatic castration-sensitive and resistant prostate cancer (mCRPC). Treatment outcome is associated with plasma trough concentrations (Cmin) of abiraterone. Patients with a plasma Cmin below the target of 8.4 ng/mL may benefit from treatment optimization by dose increase or concomitant intake with food. This study aims to investigate the cost-effectiveness of monitoring abiraterone Cmin in patients with mCRPC. METHODS: A Markov model was built with health states progression-free survival, progressed disease, and death. The benefits of monitoring abiraterone Cmin followed by a dose increase or food intervention were modeled via a difference in the percentage of patients achieving adequate Cmin taking a healthcare payer perspective. Deterministic and probabilistic sensitivity analyses were performed to assess uncertainties and their impac to the incremental cost-effectiveness ratio (ICER). RESULTS: Monitoring abiraterone followed by a dose increase resulted in 0.149 incremental quality-adjusted life-years (QALYs) with €22 145 incremental costs and an ICER of €177 821/QALY. The food intervention assumed equal effects and estimated incremental costs of €7599, resulting in an ICER of €61 019/QALY. The likelihoods of therapeutic drug monitoring (TDM) with a dose increase or food intervention being cost-effective were 8.04%and 81.9%, respectively. CONCLUSIONS: Monitoring abiraterone followed by a dose increase is not cost-effective in patients with mCRPC from a healthcare payer perspective. Monitoring in combination with a food intervention is likely to be cost-effective. This cost-effectiveness assessment may assist decision making in future integration of abiraterone TDM followed by a food intervention into standard abiraterone acetate treatment practices of mCRPC patients.

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.

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.

Cost-effectiveness analysis of Abiraterone Acetate versus Docetaxel in the management of metastatic castration-sensitive prostate cancer: Hong Kong's perspective.

BACKGROUND: Several randomized control trials (RCTs) have showed that adding either abiraterone acetate (AA) or docetaxel (D) to androgen-deprivation therapy (ADT) improves survival of metastatic castration-sensitive prostate cancer patients (mCSPC). Yet, the cost-effectiveness of these treatment options has not been fully compared under Hong Kong's setting. This cost-effectiveness analysis (CEA) serves as the first study in Hong Kong to compare the economic value of these two combinations ADT + AA vs. ADT + D. METHODS: A deterministic Markov model is used to project cost-effectiveness of each treatment until death. Survival curves for progression/death were extracted and digitized from the five RCTs (CHAARTED, LATITUDE, two STAMPEDE (2016/2017), and GETUG-AFU15). Clinically significant adverse events (AEs) were modeled; utility values were obtained from the literature. Primary outcomes were the quality-adjusted life years (QALYs) and incremental cost-effectiveness ratio (ICER). We used the societal perspective from Hong Kong and considered three times of local gross domestic product per capita (GDPpc) as the willingness-to-pay (WTP) threshold (i.e., US$138,649). We estimated the break-even cost of AA in case ADT + AA is not a cost-effective strategy under this WTP threshold. While considering the standard AA dosage (1000 mg) as the main analysis, we also examined the potential impact of the low-dose AA (250 mg) strategy. RESULTS: Integrating simulations with probabilistic sensitivity analysis, ADT + D returns 0.79 (median; 95% credible interval 0.56-0.97) QALY with an ICER of US$14,397/QALY ($7824-22,632) compared to ADT-alone. A head-to-head comparison indicates that ADT + AA further gains 0.79 (0.45-1.17) QALY but with an ICER of $361,439/QALY ($260,615-599,683) when compared to ADT + D. Considering three times of GDPpc as WTP threshold, ADT + D is more cost-effective in all simulations; while ADT + AA is more cost-effective than ADT + D only if the cost of AA is reduced by at least 63%. The low-dose AA (250 mg) strategy is potentially cost-effective when it generates equivalent efficacy as the standard dosage (1000 mg). CONCLUSIONS: ADT + D is therefore shown to be a more cost-effective strategy than ADT + AA in metastatic castration-sensitive prostate cancer patients in developed economies. Addition of AA substantially improved QALY compared to D but at a significant cost.

Cross-national drug price comparisons with economic weights in external reference pricing in Germany.

BACKGROUND: Since 2012, the pharmaceutical reimbursement legislation in Germany has been applying external reference pricing that uses country-specific economic weights for foreign prices. However, the law does not specify technical details. Therefore, we develop a proposal on how national income weights can be taken into consideration. AREAS COVERED: We develop weighting schemes that draw on gross domestic product per capita and adjust for purchasing power parities and exchange rates. In a second step, we populate the weighting schemes with economic data as well as with the price data for a pharmaceutical product (abiraterone acetate). Weighting the price of abiraterone acetate by gross domestic product per capita indicates potential price differentials of up to 43 percentage points across European prices in the German basket. EXPERT COMMENTARY: The weighting of foreign pharmaceutical prices by economic indicators, i.e. gross domestic product per capita, can capture economic differences across countries. It would also allow for differential Ramsey pricing which might foster innovation.

Effectiveness, safety and cost of abiraterone acetate in patients with metastatic castration-resistant prostate cancer: a real-world data analysis.

PURPOSE: New therapies with diverse mechanisms of action are available for metastatic castration-resistant prostate cancer (mCRPC). This study aims to evaluate the effectiveness, safety and cost of abiraterone acetate (AA) in patients with mCRPC. MATERIALS AND METHODS: Observational retrospective cohort study in which mCRPC patients who initiated AA between January 1, 2012 and December 31, 2017, were included. The patients were followed-up until death or March 31, 2018. Demographic, clinical and economic data were collected from the corporate electronic information systems. Survival distributions were estimated using the Kaplan-Meier method and compared using the log-rank test. RESULTS: A total of 69 mCRPC patients were started on AA, of whom 18 (26.1%) received prior chemotherapy (post-CT) and 51 (73.9%) did not receive it (CT-naïve). A PSA decline of ≥ 50% was achieved in five (27.8%) post-CT and 32 (62.7%) CT-naïve patients (p = 0.011). Median time to PSA progression, progression-free survival (PFS) and overall survival (OS) were 4.4/7.9 months (p = 0.003), 5.1/7.5 months (p = 0.034) and 12.1/21.3 months (p = 0.119), respectively, for post-CT/CT-naïve patients. Treatment-related adverse events (AEs) occurred in 10 (55.6%) post-CT and 11 (21.6%) CT-naïve patients (p = 0.007). The most common AEs were hypokalaemia (11.6%), hypertension (8.7%) and fatigue (5.8%). The cost per median PFS month and per median OS month was €2818.4/€2784.3 and €1187.9/€980.4 for post-CT/CT-naïve patients, respectively. CONCLUSIONS: CT-naïve patients treated with AA obtained a better clinical benefit in terms of effectiveness, safety and cost-effectiveness ratio than post-CT patients. The effectiveness outcomes were poorer than those reported previously in the clinical trial setting.

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.

Abiraterone Acetate for the Treatment of Chemotherapy-Naïve Metastatic Castration-Resistant Prostate Cancer: An Evidence Review Group Perspective of an NICE Single Technology Appraisal.

The National Institute for Health and Care Excellence (NICE) invited Janssen, the company manufacturing abiraterone acetate (AA; tradename Zytiga®), to submit evidence for the clinical and cost effectiveness of AA in combination with prednisone/prednisolone (AAP) compared with watchful waiting (i.e. best supportive care [BSC]) for chemotherapy-naïve patients with metastatic castration-resistant prostate cancer (mCRPC). Kleijnen Systematic Reviews Ltd (KSR), in collaboration with Maastricht University Medical Center, was commissioned as the Evidence Review Group (ERG). This paper presents a summary of the company submission (CS), the ERG report, subsequent addenda, and the development of the NICE guidance for the use of this drug in England and Wales by the Appraisal Committee (AC). The ERG produced a critical review of the clinical and cost effectiveness of AAP based on the CS. An important question in this appraisal was, according to the ERG, whether AAP followed by docetaxel is more effective than BSC followed by docetaxel. In the COU-AA-302 trial, 239 of 546 (43.8 %) AAP patients and 304 of 542 (56.1 %) BSC patients received docetaxel as subsequent therapy, following AA or placebo. The results for this specific group of patients were not presented in the CS; therefore, the ERG asked the company to provide these data in the clarification letter; however, these data were presented as commercial-in-confidence and cannot therefore be reported here. The ERG's critical assessment of the company's economic evaluation highlighted a number of concerns, including (a) not using the intention-to-treat (ITT) population; (b) inconsistencies in estimating prediction equations; (c) not fully incorporating the impact of adverse events; (d) incorrectly incorporating the new patient access scheme (PAS); and (e) the assumption that AA non-compliance leads to recoverable drug costs. Although some of these issues were adjusted in the ERG base case, the ERG could not estimate the impact of all of these issues, and thus acknowledges that there are still uncertainties concerning the cost-effectiveness evidence. With the exception of the ERG's preference for using the ITT population, the AC agreed with the approach taken in the ERG base case. The original company and ERG base-case incremental cost-effectiveness ratios (ICERs) were £46,722 and £57,688 per QALY gained, respectively; these changed to £28,563 and £38,061 per QALY gained, respectively, in the revised base cases applying a new PAS. Regarding the end-of-life criteria, after 24 months approximately 63 % of patients in the control group of the COU-AA-302 trial were still alive, and the median survival was 30.1 months (95 % CI 27.3-34.1). Therefore, it is unlikely that life expectancy would be less than 24 months. The AC stated that the most plausible ICER is likely between £28,600 and £32,800 per QALY gained, and concluded that AAP at this stage in the treatment pathway did not meet the end-of-life criterion for short life expectancy. Moreover, in March 2016, the AC produced the final guidance, stating that AAP is recommended, within its marketing authorisation, as an option for treating mCRPC.

Number needed to treat and associated incremental costs of treatment with enzalutamide versus abiraterone acetate plus prednisone in chemotherapy-naïve patients with metastatic castration-resistant prostate cancer.

OBJECTIVE: Enzalutamide (ENZA) and abiraterone acetate plus prednisone (AA) are approved second-generation hormone therapies for chemotherapy-naïve metastatic castration-resistant prostate cancer (mCRPC). This study compared ENZA with AA in chemotherapy-naïve mCRPC by calculating the number needed to treat (NNT) and associated incremental costs to achieve one additional chemotherapy-naïve patient with mCRPC free of radiographic progression, chemotherapy, or death over a 1-year time horizon. METHODS: Clinical outcomes were obtained from the PREVAIL and COU-AA-302 trials. Three outcomes were evaluated: radiographic progression-free survival, time to cytotoxic chemotherapy initiation, and overall survival at 1 year. NNT was calculated as the reciprocal of the outcome event rate difference for ENZA compared with AA. The incremental costs to achieve one additional outcome at 1 year were calculated as the difference in cost per treated patient multiplied by the NNT. Per-treated-patient costs were considered from a US payer perspective and included medications, monitoring, adverse events, post-progression treatments, and end-of-life care. RESULTS: Within a 1-year time horizon, the total cost per treated patient for ENZA was $2,666 less than AA. Compared with AA, treating 14 patients with ENZA resulted in one additional patient free of progression or death over 1 year; treating 26 patients with ENZA resulted in one additional patient with chemotherapy delayed over 1 year; and treating 91 patients with ENZA resulted in one additional patient free of death over 1 year. Therefore, ENZA is cost-effective compared with AA for all three outcomes evaluated, and the modeled results suggest ENZA is associated with potentially improved clinical outcomes in delaying chemotherapy initiation and disease progression for chemotherapy-naïve patients. The results are robust in sensitivity analyses, where the effect of changes in key model inputs and assumptions were tested. CONCLUSION: The results modeled in the present study suggest ENZA is cost-effective compared with AA for treating chemotherapy-naïve patients with mCRPC.

Cost per median overall survival month associated with abiraterone acetate and enzalutamide for treatment of patients with metastatic castration-resistant prostate cancer.

OBJECTIVE: To calculate costs per median overall survival (OS) month in chemotherapy-naïve patients with metastatic castration-resistant prostate cancer (mCRPC) treated with abiraterone acetate plus prednisone (AA + P) or enzalutamide. METHODS: Median treatment duration and median OS data from published Phase 3 clinical trials and prescribing information were used to calculate costs per median OS month based on wholesale acquisition costs (WACs) for patients with mCRPC treated with AA + P or enzalutamide. Sensitivity analyses were performed to understand how variations in treatment duration and treatment-related monitoring recommendations influenced cost per median OS month. Cost-effectiveness estimates of other Phase 3 trial outcomes were also explored: cost per month of chemotherapy avoided and per median radiographic progression-free survival (rPFS) month. RESULTS: The results demonstrated that AA + P has a lower cost per median OS month than enzalutamide ($3231 vs 4512; 28% reduction), based on the following assumptions: median treatment duration of 14 months for AA + P and 18 months for enzalutamide, median OS of 34.7 months for AA + P and 35.3 months for enzalutamide, and WAC per 30-day supply of $8007.17 for AA + P vs $8847.98 for enzalutamide. Sensitivity analyses showed that accounting for recommended treatment-related monitoring costs or assuming identical treatment durations for AA + P and enzalutamide (18 months) resulted in costs per median OS month 8-27% lower for AA + P than for enzalutamide. Costs per month of chemotherapy avoided were $4448 for AA + P and $5688 for enzalutamide, while costs per month to achieve median rPFS were $6794 for AA + P and $7963 for enzalutamide. CONCLUSIONS: This cost-effectiveness analysis demonstrated that costs per median OS month, along with costs of other Phase 3 trial outcomes, were lower for AA + P than for enzalutamide. The findings were robust to sensitivity analyses. These results have important implications for population health decision-makers evaluating the relative value of therapies for mCRPC patients.

Budget Impact of Enzalutamide for Chemotherapy-Naïve Metastatic Castration-Resistant Prostate Cancer.

BACKGROUND: Prostate cancer is expected to account for approximately one quarter of all new diagnoses of cancer in American men in 2015. The cost of prostate cancer care is expected to reach $15.1 billion by the year 2020, up from $11.9 billion in 2010. Given the high burden of prostate cancer, health care payers are interested in quantifying the potential budget impact of new therapies. OBJECTIVE: To estimate the budget impact of enzalutamide for the treatment of chemotherapy-naïve metastatic castration-resistant prostate cancer (mCRPC) from a U.S. payer perspective. METHODS: A model was developed to assess the budget impact of enzalutamide for treatment of chemotherapy-naïve mCRPC patients in a hypothetical 1-million-member U.S. health plan over a 1-year time horizon. Comparators included abiraterone acetate, sipuleucel-T, radium Ra 223 dichloride, and docetaxel. Epidemiologic data, including National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) incidence rates, were used to estimate the number of chemotherapy-naïve mCRPC patients. Dosing, administration, duration of therapy, and adverse event rates were based on package inserts and pivotal studies. Drug costs were obtained from RED BOOK and Centers for Medicare & Medicaid Services (CMS) average sales price pricing files, costs of administration and monitoring from the CMS physician fee schedule, and adverse events from the Agency for Healthcare Research and Quality Healthcare Cost and Utilization Project and published literature. Market shares were estimated for each comparator before and after adoption of enzalutamide. The incremental aggregate budget impact, per patient per year (PPPY), per patient per month (PPPM), and per member per month (PMPM), was calculated. One-way sensitivity analyses were performed. RESULTS: In a population of 115 chemotherapy-naïve mCRPC patients, adopting enzalutamide had an annual incremental budget impact of $510,641 ($4,426 PPPY, $369 PPPM, and $0.04 PMPM). Results were most sensitive to enzalutamide drug cost, size of the chemotherapy-naïve mCRPC patient population, and enzalutamide adoption rate. CONCLUSIONS: Results indicate a modest 1-year budget impact of adopting enzalutamide for chemotherapy-naïve mCRPC patients, partly because of the cost offset of a moderate incidence of adverse events and lack of additional required monitoring.