Luteinizing hormone-releasing hormone (LHRH) agonists represent one of the main cost factors in the management of patients with metastatic prostate cancer. We compared the cost-effectiveness of the five different 3-month formulations of LHRH agonists currently available for advanced prostate cancer in Italy, because these differ both in their capacity to suppress testosterone and in their acquisition costs.
A probabilistic, patient-level simulation model was developed to compare the cost-effectiveness, from the perspective of the Italian National Health Service (INHS), of leuprorelin 11.25 mg and 22.5 mg, triptorelin 11.25 mg, buserelin 9.9 mg, and goserelin 10.8 mg. The model incorporated testosterone-dependent progression-free and cancer-specific survival functions, LHRH agonist effectiveness data, and national costs and tariffs. Cox's proportional hazard models were used to compute total and progression-free survival functions based on clinical data from 129 patients with metastatic prostate cancer treated in an Italian center. Bayesian random effects models were employed to summarize evidence from published literature on testosterone suppression obtained with the available LHRH agonists.
Estimated total survival was ≈5 years, with a maximum difference between treatment options of ≈2 months. There was a mean difference of almost €2,500 in lifetime total costs between the least costly option (leuprorelin 22.5 mg) and the most expensive (goserelin In the incremental cost-effectiveness analysis, leuprorelin 22.5 mg dominated all alternatives except buserelin, which had an incremental cost-effectiveness ratio versus leuprorelin 22.5 mg of ≈€12,000 per life-month gained.
Based on modelling with meta-analysis of comparative survival data, leuprorelin 22.5 mg was the most cost-effective treatment of the available depot formulation LHRH agonists.