Bone-targeted agent treatment patterns and the impact of bone metastases on patients with advanced breast cancer in the United States

Treatment Patterns of Bone-targeting Agents Among Solid Tumor Patients With Bone Metastases: An Analysis of Electronic Health Record Data in the United States From 2014 to 2018

OBJECTIVES

This study evaluated real-world treatment patterns of approved bone-targeting agents (BTAs) with various mechanisms of action-pamidronate, zoledronic acid, and denosumab-for the prevention of skeletal-related events in patients with bone metastases (BM) from solid tumors.

METHODS

Adult patients with BM secondary to solid tumors between January 1, 2014, and December 31, 2018, were identified from the Flatiron Health Oncology Services Comprehensive Electronic Records database and categorized by BTA use and therapy type. Time from diagnosis to initiation, persistence (mean time on treatment), and compliance (≥12 administrations/year) with BTA with up to 4 years of follow-up were examined.

RESULTS

This study included 27,268 patients with BM (breast cancer, 32.7%; lung cancer, 16.5%; prostate cancer, 17.2%; and other solid tumors, 33.6%); of these, 41.4% initiated denosumab after BM diagnosis; 21.3%, zoledronic acid; 0.6%, pamidronate; and 36.7% had no treatment record. Mean (SD) time to initiation for denosumab or zoledronic acid was 68.6 (157.0) days (denosumab, 70.3 (160.4) days; zoledronic acid, 65.2 [150.2] days). Mean persistence and compliance (first year of treatment) were significantly higher for denosumab than for zoledronic acid (22.0 vs. 14.9 mo [ P <0.0001] and 42.3% vs. 34.8% [ P <0.0001], respectively). Treatment compliance was the highest in patients with breast cancer (denosumab, 48.2%; zoledronic acid, 39.1%).

CONCLUSION

Real-world BTA treatment patterns in the United States suggest that over one-third of patients with BM secondary to solid tumors remain untreated and less than 50% of the patients received ≥12 administrations/year of BTA therapy.

Treatment of bone metastases from solid tumors with bone-modifying agents: a web survey of Italian oncologists investigating patterns of practice drug prescription and prevention of side effects

PURPOSE

Optimal use of bone-modifying agents (BMAs) in patients with bone metastases from solid tumors is uncertain in some aspects: the drug choice; the planned treatment duration and long-term therapy; the prevention and management of possible side effects, including renal toxicity, hypocalcaemia, and medication-related osteonecrosis of the jaw (MRONJ).

METHODS

Italian oncologists were invited to fulfil a 24-question web survey about prescription of BMAs for bone metastases of breast cancer, prostate cancer, and other solid tumors. Prevention and management of side effects were also investigated.

RESULTS

Answers of 191 oncologists were collected. BMAs are usually prescribed at the time of diagnosis of bone metastases by 87.0% (breast cancer) and 76.1% (solid tumors except breast and prostate cancers) of oncologists; the decision is more articulated for prostate cancer (endocrine-sensitive versus castration-resistant). The creatinine level (32.3%), the availability of patient venous access (15.8%), and the type of primary neoplasm (13.6%) are the most reported factors involved in choice between bisphosphonates and denosumab. Zoledronic acid every 3 months was considered as a valid alternative to monthly administration by 94% of Italian oncologists. Oncologists reported a good confidence with measures aimed to prevent MRONJ, whereas uncertainness about prevention and management of hypocalcemia was registered.

CONCLUSION

Italian oncologists showed a high attitude in prescribing bisphosphonates or denosumab at the time of diagnosis of bone metastases, with a large application of preventive measures of side effects. Further studies are needed to investigate some controversial aspects, such as optimal drug treatment duration and long-term drug schedules.

Assessment of Bone Health Awareness and Education in Breast Cancer Patients with Bone Metastasis in the USA

Bone metastases are common in advanced breast cancer (BC) patients and increase the risk for skeletal-related events (SREs), which present a significant health and economic burden. Bone targeting agents (BTAs) can improve health-related quality of life by delaying or preventing SREs; nevertheless, a significant portion of eligible BC patients are not receiving this therapy. A bone health education needs assessment survey was conducted to examine cancer-related bone health awareness and to identify opportunities to improve bone health education. Direct-to-patient outreach was used to recruit adult BC patients in the USA self-reporting a diagnosis of bone metastasis within the past 3 years. Of the 200 patients, 59% experienced at least one SRE prior to survey participation (44% radiation to bone, 29% bone fracture, 17% spinal cord compression, 15% surgery to bone), and 83% were currently receiving a BTA. Awareness of general cancer bone health, protection strategies against SREs, and screening tests were low to moderate. Patients currently not receiving a BTA were least knowledgeable about cancer bone health, with only 40% aware of BTAs as a protective strategy, and only 26% were very or extremely satisfied with the information received from healthcare providers. Sixty-two percent of patients wanted to receive information by more than one mode of communication. Notable gaps in bone health education were observed in bone metastatic BC patients at risk for SREs, suggesting the need for earlier and more effective communication and education strategies to promote appropriate BTA use and better health outcomes.

Risk factors associated with skeletal-related events following discontinuation of denosumab treatment among patients with bone metastases from solid tumors: A real-world machine learning approach

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This study investigated SRE risk factors after densomuab treatment discontinuation.

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An unbiased machine learning approach was developed to evaluate >60 variables.

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Prior SREs and short denosumab treatment duration were primary risk factors.

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The results can guide denosumab persistence decisions and improve patient outcomes.

Background

Clinical practice guidelines recommend the use of bone-targeting agents for preventing skeletal-related events (SREs) among patients with bone metastases from solid tumors. The anti-RANKL monoclonal antibody denosumab is approved for the prevention of SREs in patients with bone metastases from solid tumors. However, real-world data are lacking on the impact of individual risk factors for SREs, specifically in the context of denosumab discontinuation.

Purpose

We aim to identify risk factors associated with SRE incidence following denosumab discontinuation using a machine learning approach to help profile patients at a higher risk of developing SREs following discontinuation of denosumab treatment.

Methods

Using the Optum PanTher Electronic Health Record repository, patients diagnosed with incident bone metastases from primary solid tumors between January 1, 2007, and September 1, 2019, were evaluated for inclusion in the study. Eligible patients received ≥ 2 consecutive 120 mg denosumab doses on a 4-week (± 14 days) schedule with a minimum follow-up of ≥ 1 year after the last denosumab dose, or an SRE occurring between days 84 and 365 after denosumab discontinuation. Extreme gradient boosting was used to develop an SRE risk prediction model evaluated on a test dataset. Multiple variables associated with patient demographics, comorbidities, laboratory values, treatments, and denosumab exposures were examined as potential factors for SRE risk using Shapley Additive Explanations (SHAP). Univariate analyses on risk factors with the highest importance from pooled and tumor-specific models were also conducted.

Results

A total of 1,414 adult cancer patients (breast: 40%, prostate: 30%, lung: 13%, other: 17%) were eligible, of whom 1,133 (80%) were assigned to model training and 281 (20%) to model evaluation. The median age at inclusion was 67 (range, 19–89) years with a median duration of denosumab treatment of 253 (range, 88–2,726) days; 490 (35%) patients experienced ≥ 1 SRE 83 days after denosumab discontinuation. Meaningful model performance was evaluated by an area under the receiver operating curve score of 77% and an F1 score of 62%; model precision was 60%, with 63% sensitivity and 78% specificity. SHAP identified several significant factors for the tumor-agnostic and tumor-specific models that predicted an increased SRE risk following denosumab discontinuation, including prior SREs, shorter denosumab treatment duration, ≥ 4 clinic visits per month with at least one hospitalization (all-cause) event from the baseline period up to discontinuation of denosumab, younger age at bone metastasis, shorter time to denosumab initiation from bone metastasis, and prostate cancer.

Conclusion

This analysis showed a higher cumulative number of SREs, prior SREs relative to denosumab initiation, a higher number of hospital visits, and a shorter denosumab treatment duration as significant factors that are associated with an increased SRE risk after discontinuation of denosumab, in both the tumor-agnostic and tumor-specific models. Our machine learning approach to SRE risk factor identification reinforces treatment guidance on the persistent use of denosumab and has the potential to help clinicians better assess a patient’s need to continue denosumab treatment and improve patient outcomes.

Assessment of Bone Health Education in US Multiple Myeloma and Solid Tumor Patients at Risk for Skeletal-Related Events

Purpose

Cancer patients with bone metastasis (BM) from solid tumors or multiple myeloma (MM) have an increased risk of painful skeletal-related events (SREs), which can decrease quality of life and increase mortality. Bone targeting agents (BTAs) can help delay or prevent SREs; however, a significant portion of eligible patients are not receiving BTA therapy. This study was conducted to understand patient awareness of cancer-related bone health and to identify opportunities to improve bone health education in cancer patients at risk of SREs.

Methods

The online BonE heAlth eduCatiOn Needs assessment (BEACON) survey included questions about patient demographics, cancer diagnosis and treatments (including BTA usage), and extent and satisfaction with bone health education received. Direct-to-patient outreach was used to recruit patients. Eligible patients were US adults with a diagnosis of self-reported MM or BM from a solid tumor (breast, lung, or prostate cancer) within the past three years.

Results

Of 125 patients, 71% were diagnosed with solid tumors with BM and 29% with MM. At least one prior SRE was experienced by 57% of patients (38% radiation to bone, 32% bone fracture, 22% spinal cord compression, and 19% surgery to bone), and 74% were currently receiving BTA therapy. Awareness of cancer bone health, protection strategies, and screening tests was low to moderate; patients were least informed of the impact of lifestyle changes (38%) and specific cancer treatments (≤35%) on bone health. Sixty-two percent of patients were not completely satisfied with the bone health education received. Patients generally wanted more information (58%) and to receive information by more than one mode of communication.

Conclusion

Notable gaps in bone health education were observed in cancer patients at risk for SREs indicating an important need for improved communication and education strategies to promote better health outcomes.