We want to congratulate Mitchell and colleagues for their important retrospective analysis of the real-world use of bone modifying agents (BMAs) in metastatic hormone-sensitive prostate cancer (1). The overuse of BMAs is an important area of concern leading to relevant toxicity, especially osteonecrosis of the jaw, and unnecessary costs. Our noninterventional, cross-sectional survey involving oncologists across Switzerland (SAKK 95/16), published March 1, 2021, also revealed the frequent administration of BMAs in this setting (2). We identified 106 patients with metastatic prostate cancer, of whom 34% were hormone-sensitive. More than one-half of these patients (52%) received a BMA (mostly denosumab) in a monthly dose, leading to estimated total yearly costs of more than 8.3 million Swiss francs (or 9.5 million US dollars if converted from Swiss francs to US dollars using the purchase power parity of 1.139 from the OECD) (3). We are pleased to see that our findings are matching with the ones by Mitchell and colleagues. Applying the Swiss costs, which are considered to be lower than in the United States, and correcting them for population (Swiss: 9 million inhabitants, USA: 329 million) (4), this misuse results in additional costs of more than 347 million US dollars per year.
The Swiss Group of Clinical Cancer Research SAKK is engaged to further optimize the use of BMAs. Zoledronic acid has shown equal efficacy when given every 3 months instead of every month in breast and prostate cancer (5). The situation is, however, unclear regarding denosumab. Our trial SAKK 96/12 (Reduse) (6) compares an application of denosumab of every 4 weeks vs every 3 months in patients with castration-resistant prostate cancer and breast cancer with bone metastases and has already accrued 1178 of 1380 patients (85%). We will therefore show in the near future if this approach of delayed interval is noninferior.
Funding
Not applicable: no funding was obtained regarding this letter. The mentioned SAKK 95/16 study was supported by Amgen. The funding agreement ensured the authors’ independence in designing the study, interpreting the data, writing, and publishing the report.
Notes
Role of the funder: Not applicable.
Disclosures: Michael Mark: Consulting fees: Merck Sharp & Dome, Roche, Astra Zeneca, Bristol Myers Squibb. Roger von Moos: Consulting fees: Amgen, GlaxoSmithKline, Novartis, Roche. Richard Cathomas: Consulting fees (institution): Merck Sharp & Dohme, Roche, Bristol Myers Squibb, Astellas Pharma, Ipsen, Sanofi, Bayer; Consulting fees (personal): Janssen; Honoraria (Institution): Debiopharm, Merck Sharp & Dohme, Bristol Myers Squibb, Astellas, Janssen. Sandro Stoffel: no conflict of interest. Silke Gillessen: Honoraria: Janssen Cilag, RSI; Consulting or Advisory role (including IDMC and Steering Committee): AAA International; Advisory role and Steering Committee: Amgen, Aranda, Astellas Pharma, Bayer, Bristol-Myers Squibb, Janssen, Menarini Silicon Biosystems, MSD Merck Sharp&Dome, S. Grasso Consulting, Orion Pharma GmbH, Pfizer, Roche, Sanofi, Telixpharma, Tolero Pharmaceuticals, Tolremo; Patents, royalties, other intellectual propert: Method for biomarker WO2009138392 Travel grant: ProteoMediX.
Author contributions: M.M., R.vM., R.C., SS, and S.G. contributed to the design and implementation of the work, to the analysis of the results, and to the writing of this correspondence.
Data Availability
The data cited in our correspondence are openly available in the published referenced papers.
Contributor Information
Michael Mark, Department of Haematology/Oncology, Kantonsspital Graubünden, Chur, Switzerland.
Roger von Moos, Department of Haematology/Oncology, Kantonsspital Graubünden, Chur, Switzerland.
Richard Cathomas, Department of Haematology/Oncology, Kantonsspital Graubünden, Chur, Switzerland.
Sandro Stoffel, Institute of Pharmaceutical Medicine, University of Basel, Basel, Switzerland.
Silke Gillessen, EOC—Istituto Oncologico della Svizzera Italiana, Bellinzona, Switzerland.
References
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The data cited in our correspondence are openly available in the published referenced papers.