Patterns of care and economic consequences of using bone-targeted agents for castration-sensitive prostate cancer patients with bone metastases to prevent skeletal-related events in Switzerland - the SAKK 95/16 prostate study.

BACKGROUND: International guidelines state that bone-targeted agents such as denosumab or zoledronic acid at doses used for bone metastasis are not indicated for patients with metastatic castration-sensitive prostate cancer (mCSPC) with bone metastases. Whereas denosumab has never been studied in this patient population, zoledronic acid has been shown to be ineffective in decreasing the risk for skeletal-related events. This study estimates the prevalence and economic consequences of real-world use of bone-targeted agents for mCSPC patients in Switzerland. METHODS: To estimate the frequency of bone-targeted agent administration and skeletal-related events, data from a non-interventional, cross-sectional survey involving oncologists across Switzerland (SAKK 95/16) was combined with data from the Swiss National Institute for Cancer Epidemiology and Registration (NICER). Economic parameters were calculated from the perspective of the healthcare system over the median time to prostate-specific antigen (PSA) progression for the extrapolated patient group, using data from NICER. The cost calculation covered costs for bone-targeted agents, their administration and skeletal-related events. The time to PSA progression (33.2 months), as well as the probability and cost of skeletal-related events were derived from the literature. RESULTS: The survey was answered by 86 physicians treating 417 patients, of whom 106 (25.4%) had prostate cancer, with 36 (34.0%) of these mCSPC. The majority of mCSPC patients (52.8%, n = 19) received bone-targeted agents monthly. Denosumab was the treatment of choice in 84.2% of patients (n = 16). Extrapolation using data from NICER indicated that 568 mCSPC patients may be treated with bone-targeted agents at doses used for bone metastasis  every year in Switzerland, leading to estimated total costs of more than CHF 8.3 million over 33.2 months. Because of its more frequent prescription and higher price, it appears that almost 93% of the total costs can be attributed to denosumab. For both denosumab and zoledronic acid, the most expensive components were the cost of administration and the drug cost, making up more than 90% of the total costs, with the rest being costs of skeletal-related events. CONCLUSIONS: This study found that the administration of bone-targeted agents in doses used for bone-metastatic diseases to prevent skeletal-related events is frequent in the setting of mCSPC and results in significant costs for the healthcare system.

Quality of life and pain in patients with metastatic bone disease from solid tumors treated with bone-targeted agents- a real-world cross-sectional study from Switzerland (SAKK 95/16).

BACKGROUND: Bone-targeted agents (BTAs) are widely used in the management of patients with bone metastases from solid tumors. Knowledge of the impact of their routine care use on patient-reported pain and bone pain-related quality of life (QoL) is limited. METHODS: This real world, cross-sectional study enrolled patients over a 3-month period through oncologists across Switzerland. Patients were ≥ 18 years, had solid tumors and at least one bone metastasis, and received routine care for bone metastases. Physicians provided data on BTA-related practices, risk of bone complications and BTA regimen. Patients completed questionnaires about pain (BPI-SF), general and bone pain-related QoL (FACT-G, FACT-BP) and treatment satisfaction (FACIT-TS-G). RESULTS: Eighteen sites recruited 417 patients. Based on the FACT-BP, 42% of the patients indicated not having bone pain. According to the BPI-SF, 28% reported no, 43% mild, 14% moderate, and 15% severe pain, respectively. Patients not treated with a BTA had better overall QoL (FACT-G: p = 0.031) and bone pain-related QoL (FACT-BP, p = 0.007) than those treated with a BTA. All pain and other QoL scales did not differ between groups. Patients perceived at 'low risk of bone complications' by their physician not receiving a BTA reported less pain and better QoL than those considered at 'low risk' but receiving BTA treatment or those considered at 'high risk' regardless of BTA treatment. Overall satisfaction with the treatment was good; almost 50% of patients reporting that they were completely satisfied. CONCLUSIONS: Overall, pain and QoL did not differ according to BTA treatment or physicians' risk perception. Patient with low risks not receiving BTA treatment reported least pain and highest QoL scores. These results may suggest that treating physicians assess bone complication risk appropriately and treat patients accordingly, but they need to be confirmed by objective determination of longitudinal skeletal complication risk.

Patterns of care for patients with metastatic bone disease in solid tumors: A cross-sectional study from Switzerland (SAKK 95/16).

BACKGROUND: Bone-targeted agents (BTAs) are widely used in the management of patients with bone metastases from solid tumors, but knowledge of their routine care use and the therapeutic implications remains limited. This non-interventional study aimed to characterize real-world BTA patterns of care in Switzerland. MATERIALS AND METHODS: Non-interventional, cross-sectional study involving oncologists from across Switzerland who completed a Treating Physician questionnaire, providing data on their clinical setting and BTA-related practices, and a Patient Characteristics and Treatment questionnaire, providing data on their patients' disease status, risk of bone complications, BTA regimen and related outcomes. Eligible patients were aged ≥ 18 years, with solid tumors and at least one bone metastasis and were receiving routine management at the participating physician's center over the 3-month study period. RESULTS: A total of 86 oncologists recruited 417 patients from across 18 centers in Switzerland (80% public hospitals; 20% private clinics). The majority of physicians (70.9%) reported prescribing BTAs in line with international guidelines; denosumab was the treatment of choice in 78.5% of patients. BTAs were widely administered (94.2%) according to a 3-4-weekly dosing regimen; 33.7% of physicians reported extending intervals to 12 weeks after an initial 2 years of treatment. Physicians appeared to use clinical judgement, as well as formal risk assessment, to guide treatment for symptomatic skeletal events. No association was seen between either BTA use, or risk of complications, and incidence of skeletal complications. Only 4.3% of patients were reported to be experiencing severe bone pain at the time of the study. CONCLUSIONS: This cross-sectional, non-interventional study found high implementation of guideline-recommended BTA prescribing, good pain control and low incidence of skeletal-related events. Long-term BTA randomized controlled trials have the potential to further optimize routine care outcomes for patients.