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 analysis of enzalutamide for patients with chemotherapy-naïve metastatic castration-resistant prostate cancer in Japan.

BACKGROUND: We aimed to evaluate cost-effectiveness of enzalutamide in chemotherapy-naïve metastatic castration-resistant prostate cancer patients in Japan. METHODS: A Markov model was developed to capture time spent by patients in various health states: stable, progression and death. Abiraterone acetate and docetaxel were set as active comparators. Clinical outcomes were obtained from the PREVAIL, COU-AA-302 and TAX327 trials. Treatment sequence, concomitant drugs and therapies for adverse events were estimated from responses to a survey by 14 Japanese prostate cancer experts. The analytic perspective was public healthcare payer, with a 10-year time horizon. The incremental cost-effectiveness ratio was estimated from quality-adjusted life-years and Japanese public healthcare costs. Probabilistic sensitivity analysis was performed to assess the robustness of the findings. RESULTS: According to the survey, the most common treatment sequences were (i) enzalutamide â†’ docetaxel â†’ cabazitaxel (enzalutamide-first sequencing), (ii) abiraterone â†’ enzalutamide â†’ docetaxel (abiraterone-first sequencing) and (iii) docetaxel→ enzalutamide â†’ cabazitaxel (docetaxel-first sequencing). In the base-case analysis, enzalutamide-first sequencing saved 1.74 million Japanese Yen versus abiraterone-first sequencing, with a 0.129 quality-adjusted life-year gain (dominant). Enzalutamide-first sequencing had a cost increase of 4.44 million Japanese Yen over docetaxel-first sequencing, with a 0.371 quality-adjusted life-years gain. The incremental cost-effectiveness ratio of enzalutamide-first sequencing versus docetaxel-first sequencing was estimated as 11.94 million Japanese Yen/quality-adjusted life-years. Probabilistic sensitivity analyses demonstrated that, compared with abiraterone-first sequencing, enzalutamide-first sequencing had an 87.4% probability of being dominant. CONCLUSIONS: Results modeled herein suggest that the enzalutamide-first sequencing is more cost-effective than the abiraterone-first sequencing, but less cost-effective than docetaxel-first sequencing for chemotherapy-naïve patients with metastatic castration-resistant prostate cancer.

Budget impact analysis of darolutamide for treatment of nonmetastatic castration-resistant prostate cancer.

BACKGROUND: Darolutamide, a structurally distinct androgen receptor inhibitor approved for the treatment of men with nonmetastatic castration-resistant prostate cancer (nmCRPC), has been shown to increase metastasis-free survival among men with nmCRPC compared with placebo. This treatment has a novel chemical structure that may also have safety, tolerability, and efficacy advantages for men with nmCRPC. OBJECTIVE: To estimate the projected budget impact of including darolutamide on a U.S. payer formulary as a treatment option for men with nmCRPC. METHODS: A budget impact model was developed to evaluate darolutamide for nmCRPC for a hypothetical 1-million-member plan over a 5-year period. Costs (drug acquisition, drug administration, and treatment-related adverse events [AEs]) were estimated for 2 scenarios: with and without darolutamide treatment for nmCRPC. The budget impact of darolutamide was calculated as the difference in costs for these 2 scenarios. An analysis for high-risk nmCRPC also was conducted. The model included treatments recommended by the National Comprehensive Cancer Network (e.g., apalutamide and enzalutamide) and potential comparators that are used but are not specifically indicated for nmCRPC. All treatments were assumed to be administered in combination with a weighted average androgen deprivation therapy comparator (consisting of luteinizing hormone-releasing hormone [LHRH] agonists, LHRH antagonists, and first-generation antiandrogens). Market share estimates were derived from interviews with physicians treating men with nmCRPC. The model includes grade 3-4 AEs, and the rates were obtained from clinical trial data. Costs were taken from publicly available sources and varied in a one-way sensitivity analysis. RESULTS: For a plan with 1 million lives, there were approximately 90 incident cases of nmCRPC (46 high risk) each year, with 332 (109 high risk) treatment-eligible cases by year 5. Darolutamide's market share increased from 3.6% in year 1 to 18% in year 5. Given the utilization of other agents, introducing darolutamide along with other targeted therapies was predicted to increase the total budget by $158,640 ($0.0132 per member per month [PMPM]) in year 1, which decreased over time to a cost savings of $149,240 ($0.0124 PMPM) by year 5. The scenario with darolutamide showed reduced AE costs each year. Similar results were observed for the high-risk nmCRPC population. CONCLUSIONS: Adding darolutamide to a U.S. payer formulary for the treatment of nmCRPC can result in a manageable increase in the budget that is partly offset by AE costs in the first 4 years, followed by a cost savings by year 5. DISCLOSURES: This study was conducted by RTI Health Solutions under the direction of Bayer U.S. and was funded by Bayer U.S., which was involved in the design of the study; collection, analysis, and interpretation of the data; writing of the report; and the decision to submit the report for publication. Miles and Purser (and/or their institutions) are employees of RTI Health Solutions and received research funding from Bayer U.S. to develop the budget impact model. Appukkuttan and Farej are employees of Bayer U.S. Wen was an employee of Bayer U.S. at the time of the study. This study was presented as a poster at the AMCP Virtual Learning Event, April 20-24, 2020.

Adherence and out-of-pocket costs among Medicare beneficiaries who are prescribed oral targeted therapies for advanced prostate cancer.

BACKGROUND: Abiraterone and enzalutamide are high-cost oral therapies that increasingly are used to treat patients with advanced prostate cancer; these agents carry the potential for significant financial consequences to patients. In the current study, the authors investigated coping and material measures of the financial hardship of these therapies among patients with Medicare Part D coverage. METHODS: The authors performed a retrospective cohort study on a 20% sample of Medicare Part D enrollees who underwent treatment with abiraterone or enzalutamide between July 2013 and June 2015. The authors described the variability in adherence rates and out-of-pocket payments among hospital referral regions in the first 6 months of therapy and determined whether adherence and out-of-pocket payments were associated with patient factors and the socioeconomic characteristics of where a patient was treated. RESULTS: There were 4153 patients who filled abiraterone or enzalutamide prescriptions through Medicare Part D in 228 hospital referral regions. The mean adherence rate was 75%. The median monthly out-of-pocket payment for abiraterone and enzalutamide was $706 (range, $0-$3505). After multilevel, multivariable adjustment for patient and regional factors, adherence was found to be lower in patients who were older (69% for patients aged ≥85 years vs 76% for patients aged <70 years; P < .01) and in those with low-income subsidies (69% in those with a subsidy vs 76% in those without a subsidy; P < .01). Both Hispanic ethnicity and living in a hospital referral region with a higher percentage of Hispanic beneficiaries were found to be independently associated with higher out-of-pocket payments for abiraterone and enzalutamide. CONCLUSIONS: There were substantial variations in the adherence rate and out-of-pocket payments among Medicare Part D beneficiaries who were prescribed abiraterone and enzalutamide. Sociodemographic patient and regional factors were found to be associated with both adherence and out-of-pocket payments.

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.

Budget Impact of Enzalutamide for Nonmetastatic Castration-Resistant Prostate Cancer.

BACKGROUND: Prostate cancer is the most common cancer and second-leading cause of cancer death among men in the United States. Prostate cancer poses a large economic burden, which increases with progression from localized to metastatic disease. Newly approved treatments for non-metastatic castration-resistant prostate cancer (nmCRPC) delay disease progression and reduce the risk of metastatic disease. Quantifying the potential budget impact of these new treatments is of interest to health care decision makers. OBJECTIVE: To estimate the budget impact of enzalutamide for the treatment of patients with nmCRPC in the United States over a 3-year time horizon. METHODS: An Excel-based model was developed to estimate the budget impact to a U.S. health plan of enzalutamide, a second-generation antiandrogen, as an add-on to androgen deprivation therapy (ADT) for the treatment of high-risk nmCRPC patients (prostate-specific antigen doubling time of ≤ 10 months). Comparators include apalutamide + ADT, bicalutamide + ADT, and ADT only. The analysis includes treatment costs for nmCRPC and for treatment after progression to metastatic castration-resistant prostate cancer (mCRPC). The treated population size was estimated from epidemiological data and literature. Dosing, duration of therapy, and adverse event rates were based on package inserts and pivotal studies. RED BOOK, Centers for Medicare & Medicaid Services fee schedules, and literature were used to obtain costs of drugs, adverse events, and health care visits. Market shares were estimated for each comparator before and after enzalutamide adoption. A 1-way sensitivity analysis was performed to quantify the impact of parameter uncertainty. RESULTS: In a hypothetical 1-million-member plan with 3% annual growth, it was estimated that there would be approximately 19 eligible incident nmCRPC patients in year 1, increasing to 20 eligible incident patients in year 3. With an assumed market share of approximately 6% for enzalutamide in year 1, the budget impact would be $106,074 ($0.009 per member per month [PMPM]). With a 26% enzalutamide share in year 3, the budget impact would be $632,729 ($0.048 PMPM). Cumulative budget impact to the health plan over 3 years is estimated to be $1,082,095 ($0.028 PMPM). The increased cost of the treatment regimen is partly offset by reduced postprogression costs. CONCLUSIONS: Treatment of nmCRPC patients with enzalutamide has a modest budget impact that is partly offset by delaying progression to mCRPC. DISCLOSURES: This research was sponsored by Astellas Pharma and Pfizer, the codevelopers of enzalutamide. All authors contributed to the development of the manuscript and maintained control over the final content. Schultz is employed by Astellas Pharma and owns stock in Gilead Sciences and Shire. O'Day and Sugarman are employees of Xcenda, which received consultancy fees from Astellas Pharma. Ramaswamy is employed by Pfizer. A synopsis of the current study was presented in poster format at the AMCP Managed Care & Specialty Pharmacy Annual Meeting 2019, in San Diego, CA, on March 25-28, 2019.

Metastatic Hormone-Sensitive Prostate Cancer: A Review of the Current Treatment Landscape.

PURPOSE: In recent years, the treatment options for metastatic hormone-sensitive prostate cancer (mHSPC) have expanded significantly. In addition to androgen deprivation therapy, the systemic treatments now include docetaxel, abiraterone, enzalutamide, and apalutamide. Radiation to the primary is also an option for select low-volume patients. METHODS: We conducted a review of the pivotal trials that have changed the practice of mHSPC. RESULTS: We describe an overview of the trials that investigated docetaxel (CHAARTED and STAMPEDE-Docetaxel), abiraterone (LATTITUDE and STAMPEDE-Abiraterone), enzalutamide (ARCHES, ENZAMET), apalutamide (TITAN), and radiation to the primary (STAMPEDE-Radiation). DISCUSSION: The treatment of mHSPC is a complex topic, and treatment choice should be individualized. Patient preferences, cost, volume of disease, and side effect profiles are important in determining which option is the best for an individual patient.

Cost-effectiveness analysis of metformin with enzalutamide in the metastatic castrate-resistant prostate cancer setting.

INTRODUCTION: Enzalutamide (Enza) is an effective treatment for metastatic castrate-resistant prostate cancer (mCPRC). However, Enza is not cost-effective (CE) at willingness to pay (WTP) thresholds from $0-$125 000/quality adjusted life years (QALYs) and is therefore a strain on valuable health care dollars. Metformin (Met) is inexpensive (~$8.00/month) and is thought to improve prostate cancer specific and overall survival compared to those not taking Met. We hypothesized that there must be an added effect Met could provide that would make Enza CE thereby alleviating this financial strain on government health care budgets. MATERIALS AND METHODS: We constructed a Markov model and performed a threshold analysis to narrow in on the added effect needed to make such a combination therapy cost-effective at various WTP thresholds. RESULTS: At a WTP threshold of $50 000/QALY Enza + Met is unlikely to be CE unless it increases Enza's efficacy by more than 30%. At a WTP threshold of $100 000, Enza + Met could be CE barring Met adds 18.73% to the efficacy of Enza. CONCLUSIONS: Enza + Met is unlikely to be CE at WTP thresholds less than $100 000/QALY; these results make sense because a therapy that is not CE at these WTP thresholds by itself is unlikely to be CE with an adjuvant therapy that keep a patient on such a treatment for even longer. Finally, our model suggests that the mCRPC setting is not the optimal place to trial adding Met as the relative costs are high and utility values low.

Cost-effectiveness model of abiraterone plus prednisone, cabazitaxel plus prednisone and enzalutamide for visceral metastatic castration resistant prostate cancer therapy after docetaxel therapy resistance.

Aims: Among patients diagnosed with prostate cancer, 10-20% will develop castration-resistant prostate cancer (CRPC) within 5 years; for 70%, CRPC will metastasize, mostly to the lungs and/or liver. We performed a cost-effectiveness model comparing abiraterone plus prednisone (ABI + PRD), cabazitaxel plus prednisone (CAB + PRD) and enzalutamide (ENZ) for visceral metastatic CRPC post-docetaxel therapy resistance. Methods: A three-state (Progression-Free, Progression, Death) lifetime Markov model was constructed to compare ABI + PRD, CAB + PRD, and ENZ from a United States healthcare payer perspective (2019 US$; discount rate 3%/yr.). Effectiveness was measured in life-years (LYs) and quality-adjusted life years (QALYs). Inputs included treatment costs, grade III/IV adverse events with incidence ≥5%, physician follow-up, lab and imaging tests. Phase III trial Kaplan-Meier curves were extrapolated to estimate overall survival and Progression-Free transition probabilities. Incremental cost-effectiveness ratios (ICERs) and utility ratios (ICURs), probabilistic sensitivity analyses (PSAs) and cost-effectiveness acceptability curves at willingness-to-pay (WTP) thresholds were estimated. Results: Models estimated 3-year overall survival rates of 1.3% for patients treated with ABI + PRD, 16.2% for CAB + PRD, and 13.2% for ENZ. Estimated Progression-Free rates at 1.5 years were 0.51% for ABI + PRD, 0.27% for CAB + PRD, and 14.47% for ENZ. LYs and QALYs were 1.20 and 0.58 respectively for ABI + PRD, 1.48 and 0.56 for CAB + PRD, and 1.58 and 0.79 for ENZ. Total treatment costs were: $115,433 for ABI + PRD, $85,337 for CAB + PRD and $109,213 for ENZ. CAB + PRD and ENZ dominated ABI + PRD due to higher LYs gained. Incremental QALYs for ENZ vs. CAB + PRD were larger than incremental LYs. The ICUR for ENZ was $103,674/QALY compared to CAB + PRD. Conclusions: This analysis found ENZ provided greater LYs and QALYs than both ABI + PRD and CAB + PRD, at a lower cost than ABI + PRD, but at a higher cost compared to CAB + PRD. For patients with visceral mCRPC after docetaxel therapy resistance, ENZ was cost-effective 92% of the time with a WTP threshold of $100,000/QALY.

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.

Dutch Economic Value of Radium-223 in Metastatic Castration-Resistant Prostate Cancer.

BACKGROUND: The treatment of metastatic castration-resistant prostate cancer has changed with the introduction of radium-223, cabazitaxel, abiraterone and enzalutamide. To assess value for money, their cost effectiveness in patients with metastatic castration-resistant prostate cancer previously treated with docetaxel from the Dutch societal perspective was investigated. METHODS: A cost-effectiveness analysis was conducted using efficacy, symptomatic skeletal-related event and safety data obtained from indirect treatment comparisons. Missing skeletal-related event data for cabazitaxel were conservatively assumed to be identical to radium-223. A Markov model combined these clinical inputs with Dutch-specific resource use and costs for metastatic castration-resistant prostate cancer treatment from a societal perspective. Total quality-adjusted life-years and costs in 2017 euros were calculated over a 5-year (lifetime) time horizon. RESULTS: Radium-223 resulted in €6092 and €4465 lower costs and 0.02 and 0.01 higher quality-adjusted life-years compared with abiraterone and cabazitaxel, respectively, demonstrating dominance of radium-223. Sensitivity analyses reveal a 64% (54%) chance of radium-223 being cost effective compared with abiraterone (cabazitaxel) at the informal €80,000 willingness-to-pay threshold. Compared with enzalutamide, radium-223 resulted in slightly lower quality-adjusted life-years (-0.06) and €7390 lower costs, revealing a 61% chance of radium-223 being cost effective compared with enzalutamide. The lower costs of radium-223 compared with abiraterone and enzalutamide are driven by lower drug costs and prevention of expensive skeletal-related events. Compared with cabazitaxel, the lower costs of radium-223 are driven by lower costs of the drug, administration and adverse events. CONCLUSION: Radium-223 may be a less costly treatment strategy offering similar gains in health benefits compared with abiraterone, cabazitaxel and enzalutamide in patients with metastatic castration-resistant prostate cancer previously treated with docetaxel from the Dutch societal perspective.

The lack of a relationship between physician payments from drug manufacturers and Medicare claims for abiraterone and enzalutamide.

BACKGROUND: Interactions between industry and prescribers have raised concerns regarding conflicts of interest. To the best of the authors' knowledge, quantitative data measuring these interactions have been limited until recently. In the current study, the authors sought to determine whether an association exists between industry payments and prescriber behavior with regard to abiraterone and enzalutamide. METHODS: Two Centers for Medicare and Medicaid Services databases were combined to analyze oncologists and urologists who received industry payments and/or prescribed abiraterone and enzalutamide. Correlation analysis was constructed on prescription count and industry payments. Multivariable median regression examined predictors of change in prescription count per dollar of industry payment. Stratifying prescribers by quantile evaluated threshold effects on prescribers. RESULTS: The number of prescriptions was similar between prescribers who did and those who did not receive industry payment for both drugs. The median industry payment amount to prescribers differed between prescribers and nonprescribers for abiraterone ($72 vs $56) and enzalutamide ($59 vs $31). Although no statistical association was found to exist between industry payment amount and prescription count for abiraterone prescribers, an association was found to exist for enzalutamide prescribers (rho = 0.31). A small change was found with regard to prescription count per dollar of industry payment for abiraterone (0.0007 prescriptions) and enzalutamide (0.0006 prescriptions). The amount of industry payment needed to predict one additional prescription was found to be lower in the fourth and fifth quantiles compared with the first through third quantiles. CONCLUSIONS: No difference in prescription count was found to exist between prescribers who received industry payments and those who did not. A positive correlation was noted between industry payments and prescription count for enzalutamide. Ease of adoption may affect differences between the 2 drugs. Cancer 2017;123:4356-62. © 2017 American Cancer Society.

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.

The unaffordable cost of M&A-driven drug prices.

Last week, Pfizer announced the $14 billion acquisition of Medivation, whose innovative prostate cancer treatment Xtandi (generic name enzalutamide) generated $2.2 billion in sales last year. The drug retails for $129,00 a year.

Enzalutamide (Xtandi) for patients with metastatic, resistant prostate cancer.

OBJECTIVE: To review the pharmacology and pharmacokinetics, and to evaluate the clinical efficacy, safety, and place in therapy of enzalutamide for the treatment of castration-resistant prostate cancer (CRPC). DATA SOURCES: A literature search through PubMed (1984 to November 2013; English language) was performed using the following keywords: MDV3100, androgen deprivation therapy, enzalutamide, CRPC, and androgen receptor antagonist. Searches were limited to published studies in humans. STUDY SELECTION AND DATA EXTRACTION: All articles in English identified from reviews, abstracts, presentations, and clinical trials of enzalutamide in humans were selected and included. DATA SYNTHESIS: Enzalutamide is an oral, nonsteroidal second-generation androgen receptor antagonist that is Food and Drug Administration-approved for the treatment of metastatic CRPC in men who were previously treated with docetaxel. Enzalutamide was superior to placebo for increasing median survival from 13.6 months to 18.4 months. Enzalutamide was well tolerated at a dose of 160 mg, with minor adverse events such as fatigue, diarrhea, musculoskeletal pain, and hot flashes. Patients with increased risk of seizure should not take enzalutamide. CONCLUSIONS: Enzalutamide is effective to slow progression of metastatic CRPC, to reduce prostate-specific antigen (PSA) levels, to decrease time to progression of PSA, to increase time to first skeletal-related events, and to increase quality of response rate. Enzalutamide was given at 160 mg/d for a median of 8 cycles of administration. Clinical trials are currently being conducted to observe if enzalutamide will be useful for treatment of other cancers and for early administration in prostate cancer.

New therapeutic options in metastatic castration-resistant prostate cancer: Can cost-effectiveness analysis help in treatment decisions?

OBJECTIVE: To evaluate the cost-effectiveness of abiraterone, cabazitaxel, and enzalutamide compared to placebo for treatment of metastatic castration-resistant prostate cancer. MATERIAL AND METHODS: A decision-tree model compared three treatment options for metastatic castration-resistant prostate cancer patients over 18 months from a societal perspective in 2012 USD. Chance nodes included baseline pain as a severity indicator, significant adverse effects (neutropenia, cardiac events, or seizures), and survival. Probabilities, survival rates, and health utilities were from clinical trials (COU-AA, TROPIC, and AFFIRM) and other published studies. Survival of enzalutamide was adjusted to match placebo groups across trials. Probabilistic sensitivity analyses, acceptability curves and net benefit calculations were performed. RESULTS: Abiraterone was the most cost-effective of the treatments ($123.4 K/quality-adjusted life year) compared to placebo, enzalutamide was $437.6 K/quality-adjusted life year compared to abiraterone, and cabazitaxel was $351.9 K/quality-adjusted life year compared to enzalutamide. Enzalutamide and cabazitaxel were not cost-effective compared to placebo at $154.3 K/quality-adjusted life year and $163.2 K/quality-adjusted life year, respectively. Acceptability curves showed abiraterone was cost-effective 29.3% of the time with a willingness to pay threshold of $100 K. The model was sensitive to changes in cost of the drugs, life expectancy, and survival rate. Sensitivity analysis shows that enzalutamide can become the most cost-effective option if the price of the medication decreased by 26% and other drug costs remained the same. CONCLUSION: Based on the cost-effective analysis, and survival adjustments necessary to match placebo groups, we would recommend abiraterone for treatment of metastatic castration-resistant prostate cancer despite not quite falling under the usually accepted willingness to pay threshold. Further analysis should examine comparative survival across the three drugs.