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 decrease in drug costs by 7.7 billion JPY per year, despite an increase in patient numbers.
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 injection frequency 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% decrease in injections while the number of patients increased by 12.9%. The shift to long-acting formulations was associated with a reduction in drug costs by 7.7 billion JPY per year.
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
The paper addresses the clinical question of how long-acting GnRH depot formulations impact the frequency of injections and associated drug costs in prostate cancer treatment. Prior research indicated that androgen deprivation therapy is essential for prostate cancer management, but the implications of switching to long-acting formulations had not been quantified in real-world settings. This study is significant as it provides empirical data on the practical benefits of such 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. The analysis included 2,276,025 patient-years, with descriptive statistics for patient numbers and drug shares, while the number of administrations and drug costs were analyzed for originator products only. Shapley value decomposition was employed to assess the factors contributing to changes in injections and drug costs.
Results
The primary finding was that injections decreased by 21.5%, from 1,275,081 to 1,000,324, indicating a significant reduction in administration frequency. The number of patients increased by 12.9%, from 269,328 to 304,181 patient-years. The shift to long-acting formulations accounted for a reduction of approximately 383,932 injections and contributed to a decrease in drug costs by 7.7 billion JPY per year.
Interpretation
These results suggest a meaningful shift towards long-acting formulations, which aligns with previous literature indicating similar oncological effects among GnRH drugs. However, the clinical significance of the reduction in injections must be weighed against the potential for confounding factors in observational data. The findings imply that transitioning to long-acting formulations could ease the treatment burden on patients, although the study's observational nature limits definitive conclusions.
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.
- The number of patients increased by 12.9%, from 269,328 to 304,181 patient-years.
- Drug cost reduced by 7.7 billion JPY per year.
Limitations
- Observational data may introduce confounding factors.
- Analysis based on a national database may not capture all treatment variables.
- Not a randomized controlled trial.