Leuprolide acetate 1-, 3- and 6-monthly depot formulations in androgen deprivation therapy for prostate cancer in nine European countries: evidence review and economic evaluation

Jaro Wex,¹ Manpreet Sidhu,² Isaac Odeyemi,² Ahmed M Abou-Setta,¹ Peny Retsa,² Bertrand Tombal<sup>3

1</sup>PharmArchitecture Limited, London, UK; ²Astellas Pharma Europe Ltd, Chertsey, UK; ³Cliniques Universitaires Saint-Luc, Brussels, Belgium

Objective: Leuprolide is an established luteinizing hormone–releasing hormone (LHRH) agonist used as first-line treatment in advanced prostate cancer. As different formulations and dosing schedules are likely to have economic implications, we aimed to evaluate their efficacy, safety, and costs in nine European countries: Austria, Belgium, Czech Republic, Hungary, Italy, Latvia, Netherlands, Poland, and Portugal.
Methods: Database searches identified 13 clinical trials of leuprolide 1- (1 M), 3- (3 M) and 6-monthly (6 M). Only data on leuprolide with Atrigel were compared for all three formulations, which had the same efficacy, safety, and adherence. Cost-minimization analysis accounting for cost of Eligard^®, specialist consultations, and diagnostics during up to 12 months follow-up was conducted. The perspective was that of public payers.
Results: No significant differences were observed in the percentages of intention-to-treat patients achieving testosterone levels ≤ 50 ng/dL following treatment with Eligard^® 1 M (93.3%), 3 M (98.3%), and 6 M (97.3%) (P > 0.05), and adverse event profiles of the three formulations were comparable. Overall, 6 M was the least expensive, with average total annual costs from €788 (Belgium) to €1839 (Portugal). The 3 M option was between 2.5% (Hungary) and 37.6% (Belgium) more expensive than 6 M; 1 M formulation was the most expensive, with costs 15.5% and 151.6% more expensive than 6 M for those countries, respectively. The 3 M option was 11.2%–45.3% less expensive than 1 M. Total costs were associated with frequency of visits for injection and monitoring. The 1 M required twelve visits, 3 M 4.4–4.8 visits, and 6 M 2.1–2.3 visits. Up to 50% additional visits could be funded with the savings resulting from switching eligible patients from 1 M and 3 M to 6 M. Results were stable in univariate and probabilistic sensitivity analyses.
Conclusion: Eligard^® formulations offer comparable efficacy and safety, but different dosing schedules require different number of visits. The 6 M formulation offers the greatest cost savings and should be considered the treatment of choice in eligible patients in Europe.

Keywords: prostate, cancer, androgen, leuprolide, Eligard, cost-effectiveness