Resources Utilization Assessment and Cost-Minimization Analysis of the 6-Monthly Formulation of Triptorelin in the Treatment of Prostate Cancer in China

Introduction

Prostate cancer is one of the most important malignant tumors threatening the health of men in China. The incidence rate among Chinese men is 10.79 per 100,000, with a mortality rate of 3.82 per 100,000, placing it among the leading causes of male cancer-related deaths.¹ The most common treatment involves the use of Gonadotropin-Releasing Hormone Agonists (GnRHa).^2,3

Currently, the commonly used GnRHa in clinical practice includes leuprorelin, goserelin, and triptorelin. These drugs include a variety of dosage forms, and the dosage forms that have been marketed in China include 1-month dosage form GnRHa (1M GnRHa) and 3-month dosage form GnRHa (3M GnRHa). 22.5 mg triptorelin (called 6M GnRHa below) is the first 6-monthly GnRHa introduced into China in 2023 and was included in the medical insurance catalog. This formulation is primarily used for patients with locally advanced or metastatic prostate cancer. Studies indicate that the efficacy and safety of the 6M GnRHa are comparable to the 1M and 3M formulations.^4,5 In addition, fewer injections result in a lower incidence of adverse reactions,⁵ reduced pain and anxiety,⁶ and improved patient compliance,⁷ ultimately enhancing the quality of life (QoL) for patients.⁸ In regions where long-acting GnRHa is available, patients prefer the 6M formulation.^9–12 Research from the UK also demonstrates that the 6M GnRHa significantly reduces both costs and time.^5,13

Despite these advantages, there is considerable uncertainty regarding the costs of transitioning from 1M and 3M to 6M GnRHa in China. Model-based analysis can inform better decisions by providing tools to assess the costs and benefits of these strategies. This study aims to comprehensively assess the time and cost associated with medical treatment and compare the resource utilization of the 6M GnRHa with the 1M/3M formulations through a cost-minimization analysis.

Materials and Methods

Overview of the Model

We adapted a previously developed cost minimization model introduced by Cornford.¹³ The time horizon is one year. Input data were sourced from published Chinese literature, and in the absence of data, expert opinions or conservative assumptions were used. A detailed summary of model parameters is provided in Table 1. To maintain consistency in the analysis, we assumed that patient compliance with different GnRHa dosage forms remained constant.

Table 1 Model Parameters

Patient Population Assumptions

Estimating the total number of patients treated with GnRHa involved three key factors: (1) the total number of patients with prostate cancer,¹⁴ (2) the distribution of patients across different disease stages, as this may influence treatment choices,¹⁵ and (3) the proportion of patients opting for GnRHa treatment at each disease stage based on treatment indications.¹⁶ Patients diagnosed with stage I or unknown stage were excluded, as they may not meet the indications for GnRHa treatment.²⁹

Resource Inputs

The study comprehensively considered the resource consumption during the medical treatment process, mainly including time and cost. Time-related factors included round-trip transportation, registration waiting for,^26–28 and injection. Since the round-trip transportation and injection time for each medical visit were unavailable, expert surveys provided estimated values. Costs were categorized into medical and social costs. Medical costs included drug acquisition, injection, and registration fees. Drug costs were calculated based on the market share of various formulations and the drug prices listed in the China Drug Catalog.^17,18 Injection fees were derived from the median in documents across 31 provinces, while registration fees accounted for both specialist and general consultations.^20–22 Social costs covered transportation²⁵ and productivity losses, with the latter referring to labor costs for individuals aged 15–65, who make up 11.96% of the population¹⁴ and missed work for medical treatment.²⁴ For those outside this age group, including 88.03% over 65 and 0.01% under 15,¹⁴ costs were estimated based on the need for accompanying care.³⁰ The relevant inputs are detailed in Table 1.

Sensitivity Analysis

To ensure the robustness of the model, we conducted a univariate sensitivity analysis for medical prices, allowing prices to fluctuate by 20%. Parameters were adjusted one by one to assess their impact on the total cost. If parameter changes resulted in values exceeding 100%, we capped them at 100% to maintain the rationality of the outcomes.

Result

Base Case Analysis

Model estimates suggest that if all prostate cancer patients switch from 1/ 3M to 6M GnRHa treatment, the overall cost would decrease despite an increase in medical costs (Table 2). The most significant savings come from reduced productivity costs, while other expenses, such as injection, registration, transportation, and productivity losses, also decrease. In terms of time-saving, patients are expected to save a total of 3,608,973.96hours annually, with each patient saving an average of 12.55hours per year (representing a 78% reduction in time spent on diagnosis and treatment). For healthcare workers, this change could save approximately 515,567.71hours annually, equivalent to about 64,445.96 working days (based on an 8-hour workday). Detailed data are provided in Figure 1.

Table 2 Cost Changes in the “Base Case” Scenario Compared to “Current Practice”

Figure 1 Time savings in the ”base case” scenario compared to the ”current practice”.

Sensitivity Analysis

As depicted in Figure 2, the 6M GnRHa remains economically advantageous under a wide range of parameter fluctuations. The factor with the most significant impact on the results was the price of the drug, which varied from -¥2,130,450,151.13 to ¥170,709,848.87.

Figure 2 Tornado diagram of one-way sensitivity analysis.

Discussion

This study is the first to conduct a cost-minimization analysis comparing the resource and cost utilization of 1M, 3M, and 6M GnRH for prostate cancer treatment in China from both social and medical perspectives. The results showed that compared with the 1M/3M GnRH, 6M GnRH increases medical costs from a medical perspective, but reduces social costs from a social perspective. The results of the sensitivity analysis showed that it saves money in many cases, but the impact on drug prices is significant.

Our findings are consistent with previous studies, which also found 6M triptorelin to be cost-effective.³¹ A real-world study in the UK and another modeling study also support this view.^5,13 In addition, a discrete choice trial in Japan also considered the savings of intangible costs, and its results were similar to ours.³² Since the calculation of intangible costs is difficult and controversial, our study did not calculate this part of the cost. However, whether or not this part of the cost is included does not affect our research conclusions.

Differences in the availability of dosage forms exist globally. According to a 2021 survey, approximately 2/3 of prostate cancer patients in China use 1M GnRHa, while 2/3 of prostate cancer patients in Sweden use a 3M GnRHa.^7,16 As of 2023, the 6M GnRHa has been introduced in China and is now included in the medical insurance catalog. The findings of this study offer valuable insights into the impact of this dosage form on society, the healthcare system, and patient outcomes. Future studies based on real-world data can further validate these conclusions.

Several limitations should be noted: 1) The proportion of expert consultation, time of round-trip transportation, and injection, these data are derived from expert interviews, and conservative assumptions are used, which may introduce some uncertainty. Future studies need to expand the data set to improve the availability of the parameters; 2) The data on parameters such as registration cost and transportation cost are extracted from documents or literature in some regions, which may not fully reflect the actual situation across the country. However, sensitivity analysis tested the uncertainty of these parameters, showing they had minimal impact on the overall results; 3) The number of experts interviewed is relatively limited, and they are all from tertiary hospitals, which may lead to overestimating the treatment costs of patients. 4) The study does not include all possible medical and social costs, such as patient examination fees. However, existing research indicates that the majority of cost savings result from fewer medical visits, making it unlikely that including additional cost types would alter the overall conclusions; in fact, it could potentially reinforce them. Finally, as the efficacy and safety of different GnRHa formulations are comparable, these factors were not considered in this study.

At present, China’s medical system faces the challenge of imbalance between the supply and demand of resources, especially in the allocation of high-quality medical resources, shortage of medical professionals, and supply of efficient drugs. The introduction of the 6M triptorelin formulation, the first long-acting sustained-release option approved for prostate cancer treatment in China, offers a promising solution to help alleviate these resource constraints.