The best use of bone targeted agents (BTAs), i.e. how patients (pts) profit most from treatment, optimal timing of treatment start and frequency of administration as well as duration of treatment is unclear to date.
Physicians were asked to indicate the criteria they use for the indication and administration of BTAs in pts with bone metastases from solid tumors in Switzerland (physician-related outcomes, PO) during a period of 3 months. Patterns of care (POC) was assessed by questions about reasons for BTA administration, treatment pattern, patient characteristics, and actual treatment. Pts completed a pain and bone-pain related quality of life questionnaire.
PO: Most of the physicians reported to start treatment with BTAs according to current guidelines (70.9%, 61/86). A smaller proportion would first assess the risk (high vs low) for developing skeletal-related events (SREs) to decide about treatment initiation (24.4%, 21/86). Factors contributing to define high risk were former SREs (89.5%, 77/86), lytic bone metastases (87.2%, 75/86), and high burden of disease (67.4%, 58/86), respectively. POC: The majority of the pts have been treated with BTAs immediately after the diagnosis of bone metastases (73.6%, 307/417). The main reasons for treatment with BTAs were high risk of bone complications (43%, 132/307), bone pain (21.8%, 67/307), and location of bone metastases (10.1%, 31/307), respectively. Denosumab was the most frequently used BTA (78.5%; 241/307), and a 3-4 week interval was most common (88.9%; 273/307). SREs were reported in 8.5% of treated vs 7.3% of non-treated pts, and were similar in pts rated as low or as high risk (about 8%).
The majority of the pts was treated according to current guideline recommendations with regard to start and interval of BTA treatment. The number of SREs was low irrespective of BTA treatment or risk classification for SREs, which may reflect a high impact of systemic cancer treatment on SRE reduction, or a selection of the pts according to risk factors not defined as the ones in the literature.
Clinical trial identification
Legal entity responsible for the study
M.T. Mark: Advisory / Consultancy: Roche; Advisory / Consultancy: MSD; Advisory / Consultancy: Böhringer Ingelheim; Advisory / Consultancy: Takeda; Advisory / Consultancy: BMS. B.J.K. Thuerlimann: Advisory / Consultancy, Travel / Accommodation / Expenses, Shareholder / Stockholder / Stock options: Roche; Shareholder / Stockholder / Stock options: Novartis; Advisory / Consultancy: Lilly; Advisory / Consultancy: Amgen; Advisory / Consultancy: AstraZeneca; Advisory / Consultancy: Pfizer. R. von Moos: Advisory / Consultancy: amgen; Advisory / Consultancy: BMS; Advisory / Consultancy, Research grant / Funding (institution): Merck; Advisory / Consultancy: Novartis; Honoraria (self), Advisory / Consultancy: Roche; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Bayer; Advisory / Consultancy: Pfizer. All other authors have declared no conflicts of interest.