Fewer Injections and Lower Drug Costs With Long-Acting GnRH Depot Formulations: A Nationwide Analysis of 2.3 Million Patient-Years in Japan.
The shift to long-acting GnRH formulations resulted in a 21.5% reduction in injections and a significant decrease in drug costs, suggesting a potential benefit for patient management in prostate cancer.
Where it sits
this study against the rest of the degarelix corpusSummary and findings
This study analyzed the impact of long-acting GnRH depot formulations on the number of injections and drug costs in men aged 40 years or older with prostate cancer. A total of 2,276,025 patient-years were evaluated, revealing a 21.5% reduction in injections and a decrease in drug costs by 7.7 billion JPY per year. The findings suggest a shift towards long-acting formulations without compromising oncological effects.
Abstract
<h4>Background</h4>Androgen deprivation therapy (ADT) is the base of treatment for prostate cancer, and gonadotropin-releasing hormone (GnRH) drugs are given as depot injections. Long-acting formulations may reduce the number of injections and the drug cost, but this impact has not been quantified in real practice.<h4>Methods</h4>We used the National Database Open Data of Japan from fiscal year (FY) 2017 to FY2024, and studied leuprorelin, goserelin, and degarelix in men aged 40 years or older. Patient-years were estimated by weighting the dispensed quantity by the period that each formulation covers. Descriptive statistics (patient numbers, drug, and formulation shares) were based on all products, whereas the analyses of the number of administrations and drug cost were restricted to originator products. Shapley value decomposition was used to divide the change in injections and in drug cost into factors.<h4>Results</h4>In total, 2 276 025 patient-years were analyzed. The share of each drug did not change greatly, but a clear shift to long-acting formulations was seen. The 6-month formulation of leuprorelin exceeded the 3-month formulation in FY2021 and was used more often in older patients. The number of patients increased by 12.9% (from 269 328 to 304 181 patient-years; +10.0% for originator products, used for the administration and cost analyses), but injections decreased by 21.5%, from 1 275 081 to 1 000 324. Injections per patient per year decreased from 4.97 to 3.55. The shift to long-acting formulations was the main factor for this decrease (-383 932 injections), and it also reduced the drug cost by 7.7 billion JPY per year.<h4>Conclusions</h4>The shift to long-acting GnRH formulations was associated with a reduction in injections of about one in five, even though the number of patients increased and was estimated to account for part of the reduction in drug cost. Because the oncological effect is similar among GnRH drugs, a further shift to long-acting formulations may lower the burden on patients and on health care.
Background
This paper addresses the efficiency of androgen deprivation therapy (ADT) for prostate cancer, specifically focusing on the use of gonadotropin-releasing hormone (GnRH) depot injections. Prior studies have indicated that long-acting formulations could potentially reduce the number of injections and associated costs, but empirical data on their real-world impact has been lacking. This study is significant as it provides a nationwide analysis of patient-years in Japan, quantifying the effects of long-acting formulations.
Methods
The study utilized the National Database Open Data of Japan from fiscal year 2017 to FY2024, focusing on men aged 40 years or older receiving leuprorelin, goserelin, and degarelix. A total of 2,276,025 patient-years were analyzed, with descriptive statistics based on all products and specific analyses on originator products for injections and cost. Shapley value decomposition was employed to assess the factors contributing to changes in injections and drug costs.
Results
The primary finding indicated that injections decreased by 21.5%, from 1,275,081 to 1,000,324, while the number of patients increased by 12.9%, from 269,328 to 304,181. The average injections per patient per year fell from 4.97 to 3.55. The shift to long-acting formulations accounted for a reduction of 383,932 injections and contributed to a drug cost reduction of 7.7 billion JPY per year.
Interpretation
These results suggest a meaningful shift towards long-acting GnRH formulations, which aligns with previous literature indicating potential benefits in reducing treatment burden. However, while the statistical significance of the findings is clear, the clinical significance may vary based on individual patient circumstances. Limitations include the observational nature of the study and potential confounding factors that were not controlled for, which may affect the generalizability of the results to other populations or healthcare systems.
Key findings
- 2,276,025 patient-years analyzed.
- Injections decreased by 21.5%, from 1,275,081 to 1,000,324.
- Injections per patient per year decreased from 4.97 to 3.55.
- Drug cost reduced by 7.7 billion JPY per year.
- Number of patients increased by 12.9%, from 269,328 to 304,181.
Limitations
- Observational study design may introduce confounding factors.
- Findings may not be generalizable beyond the Japanese healthcare system.
- Analysis limited to originator products only.