Cost-effectiveness analysis of cabazitaxel for metastatic castration resistant prostate cancer after docetaxel and androgen-signaling-targeted inhibitor resistance

Cost-Effectiveness Analysis for Therapy Sequence in Advanced Cancer: A Microsimulation Approach with Application to Metastatic Prostate Cancer

PURPOSE

Patients with advanced cancer may undergo multiple lines of treatment, switching therapies as their disease progresses. We developed a general microsimulation framework to study therapy sequence and applied it to metastatic prostate cancer.

METHODS

We constructed a discrete-time state transition model to study 2 lines of therapy. Using digitized published survival curves (progression-free survival, time to progression, and overall survival [OS]), we inferred event types (progression or death) and estimated transition probabilities using cumulative incidence functions with competing risks. We incorporated within-patient dependence over time; first-line therapy response informed subsequent event probabilities. Parameters governing within-patient dependence calibrated the model-based results to a target clinical trial. We applied these methods to 2 therapy sequences for metastatic prostate cancer, wherein both docetaxel (DCT) and abiraterone acetate (AA) are appropriate for either first- or second-line treatment. We assessed costs and quality-adjusted life-years (5-y QALYs) for 2 treatment strategies: DCT → AA versus AA → DCT.

RESULTS

Models assuming within-patient independence overestimated OS time, which corrected with the calibration approach. With generic pricing, AA → DCT dominated DCT → AA, (higher 5-y QALYs and lower costs), consistent for all values of calibration parameters (including no correction). Model calibration increased the difference in 5-y QALYs between treatment strategies (0.07 uncorrected v. 0.15 with base-case correction). Applying the correction decreased the estimated difference in cost (-$5,360 uncorrected v. -$3,066 corrected). Results were strongly affected by the cost of AA. Under a lifetime horizon, AA → DCT was no longer dominant but still cost-effective (incremental cost-effectiveness ratio: $19,463).

CONCLUSIONS

We demonstrate a microsimulation approach to study the cost-effectiveness of therapy sequences for advanced prostate cancer, taking care to account for within-patient dependence.

HIGHLIGHTS

We developed a discrete-time state transition model for studying therapy sequence in advanced cancers.Results are sensitive to dependence within patients.A calibration approach can introduce dependence across lines of therapy and closely match simulation outcomes to target trial outcomes.

Treatment landscape and burden of disease in metastatic castration-resistant prostate cancer: systematic and structured literature reviews

Purpose

Metastatic castration-resistant prostate cancer (mCRPC) is a lethal disease that imposes a major burden on patients and healthcare systems. Three structured literature reviews (treatment guidelines, treatment landscape, and human/clinical/patient burden) and one systematic literature review (economic burden) were conducted to better understand the disease burden and unmet needs for patients with late-stage mCRPC, for whom optimal treatment options are unclear.

Methods

Embase®, MEDLINE®, MEDLINE® In-Process, the CENTRAL database (structured and systematic reviews), and the Centre for Reviews and Dissemination database (systematic review only) were searched for English-language records from 2009 to 2021 to identify mCRPC treatment guidelines and studies related to the treatment landscape and the humanistic/economic burden of mCRPC in adult men (aged ≥18 years) of any ethnicity.

Results

In total, six records were included for the treatment patterns review, 14 records for humanistic burden, nine records for economic burden, three records (two studies) for efficacy, and eight records for safety. Real-world treatment patterns were broadly aligned with treatment guidelines and provided no optimal treatment sequencing beyond second line other than palliative care. Current post-docetaxel treatments in mCRPC are associated with adverse events that cause relatively high rates of treatment discontinuation or disruption. The humanistic and economic burdens associated with mCRPC are high.

Conclusion

The findings highlight a lack of treatment options with novel mechanisms of action and more tolerable safety profiles that satisfy a risk-to-benefit ratio aligned with patient needs and preferences for patients with late-stage mCRPC. Treatment approaches that improve survival and health-related quality of life are needed, ideally while simultaneously reducing costs and healthcare resource utilization.

Cost-Effectiveness Analysis of 177Lu-PSMA-617 Radioligand Therapy in Metastatic Castration-Resistant Prostate Cancer

BACKGROUND

Metastatic castration-resistant prostate cancer poses a therapeutic challenge with poor prognosis. The VISION trial showed prolonged progression-free and overall survival in patients treated with lutetium Lu 177 vipivotide tetraxetan (177Lu-PSMA-617) radioligand therapy compared with using the standard of care (SoC) alone. The objective of this study was to determine the cost-effectiveness of 177Lu-PSMA-617 treatment compared with SoC therapy.

METHODS

A partitioned survival model was developed using data from the VISION trial, which included overall and progression-free survival and treatment regimens for 177Lu-PSMA-617 and SoC. Treatment costs, utilities for health states, and adverse events were derived from public databases and the literature. Because 177Lu-PSMA-617 was only recently approved, costs for treatment were extrapolated from 177Lu-DOTATATE. Outcome measurements included the incremental cost, effectiveness, and cost-effectiveness ratio. The analysis was performed in a US setting from a healthcare system perspective over the lifetime horizon of 60 months. The willingness-to-pay threshold was set to $50,000, $100,000, and $200,000 per quality-adjusted life years (QALYs).

RESULTS

The 177Lu-PSMA-617 group was estimated to gain 0.42 incremental QALYs. Treatment using 177Lu-PSMA-617 led to an increase in costs compared with SoC ($169,110 vs $85,398). The incremental cost, effectiveness, and cost-effectiveness ratio for 177Lu-PSMA-617 therapy was $200,708/QALYs. Sensitivity analysis showed robustness of the model regarding various parameters, which remained cost-effective at all lower and upper parameter bounds. In probabilistic sensitivity analysis using Monte Carlo simulation with 10,000 iterations, therapy using 177Lu-PSMA-617 was determined as the cost-effective strategy in 37.14% of all iterations at a willingness-to-pay threshold of $200,000/QALYs.

CONCLUSIONS

Treatment using 177Lu-PSMA-617 was estimated to add a notable clinical benefit over SoC alone. Based on the model results, radioligand therapy represents a treatment strategy for patients with metastatic castration-resistant prostate cancer with cost-effectiveness in certain scenarios.

Cost-effectiveness of olaparib, a PARP inhibitor, for patients with metastatic castration-resistant prostate cancer in China and United States

Background

Metastatic prostate cancer is initially sensitive to androgen receptor inhibition, but eventually becomes metastatic castration-resistant prostate cancer (mCRPC). Olaparib has longer progression-free survival and better measures of response and patient-reported end points than either enzalutamide or abiraterone. In the present study, 2 Markov models were established to analyze the cost utility of olaparib in treating mCRPC from the perspectives of health services in China and the United States.

Methods

Markov models were established to simulate the progress of mCRPC in China and the United States. The state transition probabilities and clinical data were extracted from the PROfound trial. The cost data were estimated from local pricing, the relevant literature and expert consultancy. The health outcomes are expressed by quality-adjusted life years (QALYs). All costs and incremental cost-effectiveness ratios (ICERs) are presented in US dollars. One-way deterministic sensitivity analysis and probabilistic sensitivity analysis were performed to assess the uncertainty of the models.

Results

Based on the Chinese Markov model, the base case ICER for olaparib versus the control group was ¥392,727.87, with incremental costs of ¥93,673.23 and an incremental QALY of 0.23, indicating that it was not cost effective from the aspect of the Chinese healthcare system. However, as shown by the American Markov model, olaparib was dominant versus the control group, with a cost saving of $69,675.20 and a gain of 0.23 QALYs. One-way deterministic sensitivity analysis and probabilistic sensitivity analyses showed that the modeling results were not significantly affected by the model parameters.

Conclusions

Olaparib treatment in patients with mCRPC is not cost effective in China, but it is cost saving in the United States.

The Health Economics of Metastatic Hormone-Sensitive and Non-Metastatic Castration-Resistant Prostate Cancer—A Systematic Literature Review with Application to the Canadian Context

Background: Health economic evaluations are needed to assess the impact on the healthcare system of emerging treatment patterns for advanced prostate cancer. The objective of this study is to review the scientific literature identifying cost-effectiveness and cost analyses that are assessing treatments for metastatic hormone-sensitive prostate cancer (mHSPC) and nonmetastatic castration-resistant prostate cancer (nmCRPC). Methods: On 29 June 2021, we searched the scientific (MEDLINE, Embase, and EBSCO) and grey literature for health economic studies targeting mHSPC and nmCRPC. We used the CHEC-extended checklist and the Welte checklist for risk-of-bias assessment and transferability analysis, respectively. Results: We retained 20 cost-effectiveness and 4 cost analyses in the mHSPC setting, and 14 cost-effectiveness and 6 cost analyses in the nmCRPC setting. Docetaxel in combination with androgen deprivation therapy (ADT) was the most cost-effective treatment in the mHSPC setting. Apalutamide, darolutamide, and enzalutamide presented similar results vs. ADT alone and were identified as cost-effective treatments for nmCRPC. An increase in costs as patients transitioned from nmCRPC to mCRPC was noted. Conclusions: We concluded that there is an important unmet need for health economic evaluations in the mHSPC and nmCRPC setting incorporating real-world data to support healthcare decision making.

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

AIMS

There are no direct comparisons of the relative cost-effectiveness of second-generation anti-androgens (enzalutamide and apalutamide) used in managing metastatic castration-sensitive prostate cancer (mCSPC) in Canada. This study compared the cost-effectiveness of enzalutamide versus apalutamide versus androgen deprivation therapy (ADT) alone (standard of care) in patients with mCSPC from the Canadian public payer perspective using a Markov model with a 15-year time horizon.

MATERIALS AND METHODS

Efficacy data for enzalutamide and ADT alone were informed by the ARCHES and ENZAMET clinical trials, while a Bayesian network meta-analysis enabled comparison with apalutamide and ADT alone.

RESULTS

Over the 15-year period, enzalutamide achieved the highest number of life-years (LY, 7.6) and quality-adjusted life-years (QALY, 5.62) compared with apalutamide (LY, 6.1; QALY, 4.59) and ADTs (LY, 4.9; QALY, 3.61). Enzalutamide incurred the most costs ($349,345) compared with apalutamide ($294,349) and ADT ($162,550). Sequential analysis showed that enzalutamide lies on the cost-effectiveness frontier with ADT alone (incremental cost-effectiveness ratio: $92,868/QALY), with apalutamide extendedly dominated through enzalutamide and ADT alone.

LIMITATIONS

Limitations include the heterogeneity of the studies included in the network meta-analysis and the validations for the treatment sequencing assumptions in the modeling.

CONCLUSIONS

Enzalutamide was the most effective treatment option for mCSPC in the Canadian market, with the greatest LYs and QALYs, and incurred the most costs.