Disease and Treatment Characteristics of Men Diagnosed With Metastatic Hormone-Sensitive Prostate Cancer in Real Life: Analysis From a Commercial Claims Database

Does Research from Clinical Trials in Metastatic Hormone-sensitive Prostate Cancer Treatment Translate into Access to Treatments for Patients in the "Real World"? A Systematic Review

CONTEXT

Since 2015 there have been major advances in the management of primary metastatic hormone-sensitive prostate cancer (mHSPC) following the publication of key clinical trials that demonstrated significant clinical benefits with docetaxel chemotherapy or novel hormone therapy (NHT) in addition to androgen deprivation therapy (ADT). Despite these advances, there is evidence to show that these treatments are not being utilised for mHSPC in clinical practice.

OBJECTIVE

To determine the utilisation of docetaxel and NHT in mHSPC in routine practice and the determinants of variation in their use.

EVIDENCE ACQUISITION

MEDLINE and Embase were searched systematically for studies on utilisation of treatments for primary mHSPC that were based on regional or national data sets and published after January 2005. Study results were summarised using a narrative synthesis.

EVIDENCE SYNTHESIS

Thirteen papers were included in the analysis, six full-text articles and seven abstracts, on studies that included a total of 166 876 patients. The utilisation rate of treatment intensification with either docetaxel or NHT (enzalutamide, apalutamide, or abiraterone) in addition to ADT ranged from 9.3% to 38.1% across the studies. Younger, White patients with fewer comorbidities and living in more urban settings were more likely to be prescribed treatment intensification. Patients treated in private academic institutions by oncologists were more likely to receive docetaxel or NHT. Socioeconomic status did not impact receipt of systemic therapy. NHT utilisation rates appear to have increased over time.

CONCLUSIONS

These results highlight the need to change the approach to the treatment of primary mHSPC in the real world by harnessing the practice-changing results from recent trials in this setting to optimise upfront systemic therapy for this patient population.

PATIENT SUMMARY

We reviewed the use of treatments for primary metastatic hormone-sensitive prostate cancer that showed a benefit in key clinical trials. We found that these treatments are underused, particularly among certain patient groups.

Survival of veterans treated with enzalutamide and abiraterone for metastatic castrate resistant prostate cancer based on comorbid diseases

BACKGROUND

Comorbid diseases influence patient outcomes, yet little is known about how comorbidities interact with treatments for metastatic castrate-resistant prostate cancer (mCRPC). No head-to-head trials have compared the efficacy of abiraterone and enzalutamide - oral androgen-receptor targeted agents (ARTAs) for mCRPC. In patients with comorbid disease, outcomes with ARTAs may differ due to disparate mechanisms of action, adverse events, and drug interactions.

METHODS

Retrospective observational study of US veterans initiating treatment for mCRPC with abiraterone or enzalutamide between September 2014 and June 2017. Treatment duration and overall survival (OS) was compared based on age and comorbid diseases. The association between ARTA and OS was assessed using Cox proportional hazards and propensity-score matched modeling while adjusting for potential confounders. Sensitivity analyses were performed based on patient age, comorbidities, and subsequent treatments for mCRPC.

RESULTS

Of 5822 veterans treated for mCRPC, 43.0% initially received enzalutamide and 57.0% abiraterone. Veterans initially treated with enzalutamide versus abiraterone were older (mean 75.8 vs. 75.0 years) with higher mean Charlson comorbidity index (4.4 vs. 4.1), and higher rates of cardiovascular disease or diabetes (74.2% vs. 70.6%). In the entire population, veterans initially treated with enzalutamide had longer median OS compared to those initially treated with abiraterone (24.2 vs. 22.1 months, p = 0.001). In veterans with cardiovascular disease or diabetes, median treatment duration with enzalutamide was longer (11.4 vs. 8.6 months, p < 0.001) with longer median OS compared to abiraterone (23.2 vs. 20.5 months, p < 0.001). In a propensity score matched cohort, enzalutamide was associated with decreased mortality compared to abiraterone (HR 0.90, 95% CI 0.84-0.96).

CONCLUSIONS

Veterans with cardiovascular disease or diabetes had longer treatment duration and OS with enzalutamide compared to abiraterone. Further study of ARTA selection may benefit men with metastatic castrate resistant prostate cancer and likely hormone sensitive prostate cancer, especially among patients with comorbid diseases.

Treatment patterns and survival in metastatic castration-sensitive prostate cancer in the US Veterans Health Administration

BACKGROUND

Limited real-world data exist on treatment patterns and outcomes in patients with metastatic castration-sensitive prostate cancer (mCSPC).

METHODS

A retrospective cohort study was conducted, using the Veterans Health Administration claims database (April 2013-March 2018). Among 369,734 prostate cancer patients, we selected all men who developed metastases within 90 days before or after medical/surgical castration and who received androgen deprivation therapy (ADT). Patients were categorized into four cohorts: ADT-only (± <90-day nonsteroidal anti-androgen [NSAA] use), ADT + NSAA, ADT + docetaxel, and ADT + abiraterone. Main outcomes were treatment patterns, time-to-progression to metastatic castration-resistant disease, and overall survival. Multivariable analysis and sensitivity analysis were conducted.

RESULTS

Of 1395 patients, 874 (63%) received ADT-only, 338 (24%) received ADT + NSAA, 108 (8%) received ADT + docetaxel, and 75 (5%) received ADT + abiraterone. Proportions on ADT-only and ADT + NSAA declined (from 66% to 60% and from 31% to 17%, respectively) over the study period, while proportions prescribed ADT + docetaxel or abiraterone increased from 3% to 9% and from 1% to 15%, respectively. Patients treated with ADT + NSAA had similar risks of castration-resistant disease (hazard ratio [HR] 1.05; 95% confidence interval [CI]: 0.87, 1.26) and overall mortality (HR 1.22; 95% CI: 0.97, 1.54) as ADT-only.

CONCLUSIONS

Most patients with mCSPC initiating ADT received ADT-only or ADT + NSAA, despite the emergence of docetaxel and novel hormonal therapies. Even in the most recent period (2017 to early 2018), only 24% of men received intensified therapy with agents known to prolong survival versus ADT-only. These data in real-world clinical practice suggest substantial room for improved outcomes in patients with mCSPC.

Contemporary use of real-world data for clinical trial conduct in the United States: a scoping review

OBJECTIVE

Real-world data (RWD), defined as routinely collected healthcare data, can be a potential catalyst for addressing challenges faced in clinical trials. We performed a scoping review of database-specific RWD applications within clinical trial contexts, synthesizing prominent uses and themes.

MATERIALS AND METHODS

Querying 3 biomedical literature databases, research articles using electronic health records, administrative claims databases, or clinical registries either within a clinical trial or in tandem with methodology related to clinical trials were included. Articles were required to use at least 1 US RWD source. All abstract screening, full-text screening, and data extraction was performed by 1 reviewer. Two reviewers independently verified all decisions.

RESULTS

Of 2020 screened articles, 89 qualified: 59 articles used electronic health records, 29 used administrative claims, and 26 used registries. Our synthesis was driven by the general life cycle of a clinical trial, culminating into 3 major themes: trial process tasks (51 articles); dissemination strategies (6); and generalizability assessments (34). Despite a diverse set of diseases studied, <10% of trials using RWD for trial process tasks evaluated medications or procedures (5/51). All articles highlighted data-related challenges, such as missing values.

DISCUSSION

Database-specific RWD have been occasionally leveraged for various clinical trial tasks. We observed underuse of RWD within conducted medication or procedure trials, though it is subject to the confounder of implicit report of RWD use.

CONCLUSION

Enhanced incorporation of RWD should be further explored for medication or procedure trials, including better understanding of how to handle related data quality issues to facilitate RWD use.

Identification of patients with metastatic castration-sensitive or metastatic castration-resistant prostate cancer using administrative health claims and laboratory data

OBJECTIVE

To develop algorithms to identify metastatic castration-sensitive prostate cancer (mCSPC) patients and castration-resistant prostate cancer (mCRPC) patients, using health claims data and laboratory test results.

METHODS

A targeted literature review summarized mCSPC and mCRPC patient selection criteria previously used in real-world retrospective studies. Novel algorithms to identify mCSPC and mCRPC were developed based on diagnosis codes indicating hormone sensitivity/resistance, prostate-specific antigen (PSA) test results, and claims for castration and mCRPC-specific treatments. These algorithms were applied to claims data from Optum Clinformatics Extended DataMart (Date of Death) Databases (commercial insurance/Medicare Advantage [COM/MA]; 01 January 2014-31 July 2019) and Medicare Fee-for-Service (Medicare-FFS; 01 January 2014-31 December 2017).

RESULTS

Previous real-world studies identified mCSPC primarily based on metastasis diagnosis codes, and mCRPC based on mCRPC-specific drugs. Using the current study's algorithms, 7034 COM/MA and 19,981 Medicare-FFS patients were identified as having mCSPC, and 2578 COM/MA and 11,554 Medicare-FFS as having mCRPC. Most mCSPC patients were identified based on evidence of being hormone/castration-naive. Patients were identified as having mCRPC most commonly based on rising PSA (COM/MA), or at the metastasis diagnosis date if it occurred after castration (Medicare-FFS). Among patients with mCSPC, 14-17% had evidence of progression to castration resistance during a median 1-year follow-up period, mostly based on use of mCRPC-specific drugs.

CONCLUSIONS

Comprehensive algorithms based on claims and laboratory data were developed to identify and distinguish patients with mCSPC and mCRPC. This will facilitate appropriate identification of mCSPC and mCRPC patients based on health claims data and better understanding of patient unmet needs in real-world settings.

Treatment patterns of prostate cancer with bone metastasis in Beijing: A real-world study using data from an administrative claims database

Purpose

To explore treatment patterns among patients with prostate cancer and bone metastasis and to compare clinical outcomes following use of different hormone therapies including combined androgen blockade (CAB), nonsteroidal antiandrogen (NSAA) monotherapy, and castration monotherapy.

Methods

We conducted a population‐based cohort study using data from the Urban Employee Basic Medical Insurance database (2011‐2014) in Beijing. We identified 475 patients with newly diagnosed bone metastatic prostate cancer with at least one prescription for hormone therapy and described their treatment patterns over a median follow‐up of 20.7 months. Cox proportional hazards model was used to compare time to chemotherapy initiation between patients starting on different hormone therapies.

Results

Hormone therapy and/or bisphosphonate therapy with zoledronic acid were the initial treatments in the majority of patients (87.8%); chemotherapy, radiotherapy, and surgery were usually given later in the treatment pathway. CAB was the most common hormone treatment (73.7%). For time to chemotherapy initiation, hazard ratios (95% confidence intervals) were 2.43 (1.08‐5.44) for NSAA alone vs CAB and 1.29 (0.78‐2.13) for castration alone vs CAB.

Conclusions

Our findings show that while a wide range of therapies are used to treat patients with prostate cancer and bone metastasis in Beijing, hormone therapy and bisphosphonate therapy are the most commonly prescribed, and use of CAB was seen to be advantageous in delaying time to chemotherapy initiation over NSAA monotherapy. Future studies should explore longer‐term treatment patterns, including use of newly approved treatments.

Burden of Metastatic Castrate Naive Prostate Cancer Patients, to Identify Men More Likely to Benefit from Early Docetaxel: Further Analyses of CHAARTED and GETUG-AFU15 Studies

BACKGROUND

Docetaxel (D) at the time of starting androgen deprivation therapy (ADT) for metastatic castrate naive prostate cancer shows a clear survival benefit for patients with high-volume (HV) disease. It is unclear whether patients with low-volume (LV) disease benefit from early D.

OBJECTIVE

To define the overall survival (OS) of aggregate data of patient subgroups from the CHAARTED and GETUG-AFU15 studies, defined by metastatic burden (HV and LV) and time of metastasis occurrence (at diagnosis or after prior local treatment [PRLT]).

DESIGN, SETTING, AND PARTICIPANTS

Data were accessed from two independent phase III trials of ADT alone or ADT+D-GETUG-AFU15 (N=385) and CHAARTED (N=790), with median follow-ups for survivors of 83.2 and 48.2 mo, respectively. The definition of HV and LV disease was harmonized.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary end point was OS.

RESULTS AND LIMITATIONS

Meta-analysis results of the aggregate data showed significant heterogeneity in ADT+D versus ADT effect sizes between HV and LV subgroups (p=0.017), and failed to detect heterogeneity in ADT+D versus ADT effect sizes between upfront and PRLT subgroups (p=0.4). Adding D in patients with HV disease has a consistent effect in improving median OS (HV-ADT: 34.4 and 35.1 mo, HV-ADT+D: 51.2 and 39.8 mo in CHAARTED and GETUG-AFU15, respectively; pooled average hazard ratio or HR (95% confidence interval [CI]) 0.68 ([95% CI 0.56; 0.82], p<0.001). Patients with LV disease showed much longer OS, without evidence that D improved OS (LV-ADT: not reached [NR] and 83.4; LV-ADT+D: 63.5 and NR in CHAARTED and GETUG-AFU15, respectively; pooled HR (95% CI) 1.03 (95% CI 0.77; 1.38). Aggregate data showed no evidence of heterogeneity of early D in LV and HV subgroups irrespective of whether patients had PRLT or not. Post hoc subgroup analysis was based on aggregated data from two independent phase III randomized trials.

CONCLUSIONS

There was no apparent survival benefit in the CHAARTED and GETUG-AFU15 studies with D for LV. Across both studies, early D showed consistent effect and improved OS in HV patients.

PATIENT SUMMARY

Patients with a higher burden of metastatic prostate cancer starting androgen deprivation therapy (ADT) have a poorer prognosis and are more likely to benefit from early docetaxel. Low-volume patients have longer overall survival with ADT alone, and the toxicity of docetaxel may outweigh its benefits.