Bone-targeted agents in the treatment of bone metastases: RANK outsider or new kid on the block?

Perceptions around bone-modifying agent use in patients with bone metastases from breast and castration resistant prostate cancer: a patient survey

BACKGROUND

Optimal use of bone-modifying agent (BMA) therapy in patients with bone metastases from breast and castrate-resistant prostate cancer (CRPC) is evolving.

METHODS

Patients receiving BMA for bone metastases from breast or CRPC were surveyed. Information was collected on patient and disease characteristics, BMA treatments and perceptions regarding BMA benefits and side effects. Interest in participation in trials of de-escalated BMA therapy was also gauged.

RESULTS

Of 220 patients contacted, 172 eligible patients responded (response rate 78%). Median age was 67 (range: 21-91); 137 (80%) had breast cancer and 35 (20%) CRPC. Symptomatic skeletal events (SSEs) occurred prior to starting BMAs in 61% (84/137) of breast and 48% (17/35) of CRPC patients. Among breast cancer patients, 47, 33 and 13% received zoledronate, pamidronate and denosumab, respectively. Eighty-five percent (30/35) of CRPC patients received denosumab. De-escalation of therapy was more common among breast cancer patients. Although most patients correctly reported the goals of BMA therapy were to "help stop fractures" (62%) and "[improve] quality of life" (63%), 46.5% felt it prolonged survival and 54% felt it reduced bone progression. Most respondents (102/129, 79%) were comfortable with de-escalating to 6-monthly treatment after 2 years of BMA therapy. Patients considered the most important endpoints of de-escalation studies to be "stability of bone metastases" (45%), "quality of life" (22%) and "SSE rates" (14%).

CONCLUSION

Twelve weekly BMA was more common in breast than in prostate cancer. There remain misconceptions about the benefits of BMAs, highlighting potential gaps in patient education. Patients were interested in further BMA de-escalation after 2 years of prior BMA and provided study endpoints that were most important to them.

Real-world practice patterns and attitudes towards de-escalation of bone-modifying agents in patients with bone metastases from breast and prostate cancer: A physician survey

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Questions around optimal use of bone-modifying agents (BMAs) still exist.

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Most physicians are de-escalating BMAs in patients with metastatic breast cancer.

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Practice varies according to patient insurance coverage.

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There is interest performing further trials of de-escalation especially after 2 years of treatment.

Background

There remain questions around the optimal use of bone-modifying agents (BMAs) in patients with bone metastases from breast and castration-resistant prostate cancer (CRPC). A physician survey was performed to identify current practices, as well as perceptions around long-term BMA use, BMA de-escalation, and further BMA de-escalation after 2 years of use.

Methods

Canadian oncologists treating breast cancer or CRPC were surveyed via an anonymized online survey. The survey collected physician demographics, current practice patterns, perception on risk of symptomatic skeletal events (SSE) and BMA-associated toxicities, and attitudes towards further de-escalation of BMAs after 2 years of treatment.

Results

A total of 334 physicians in Canada were contacted, of which 295 were eligible on initial screening, and 65 completed the survey (response rate 22%): 35 treated breast cancer, 25 treated prostate cancer and 5 treated both. The most common BMA regimens in patients with no limitation in drug coverage were denosumab q4wks for 3–4 months followed by a de-escalation to q12wks (breast cancer) and denosumab q4wks (prostate cancer). In patients with provincial health coverage only the common choices were zoledronate q4wks for 3–4 months followed by de-escalation to q12wks (breast cancer) and denosumab q4wks (prostate cancer). There was equipoise regarding the benefit of continuing BMA beyond 2 years and interest in further trials of de-escalation of BMA in both breast and prostate cancer. The most favored alternative primary study endpoints to SSE were BMA toxicity (67.2%), pain (46.9%), and physical function (48.4%).

Conclusion

Despite their extensive use and costs, questions around optimal use of BMAs still exist. Practice varies according to patient insurance coverage. However, most physicians are de-escalating BMAs. There is interest amongst clinicians in performing trials of de-escalation, especially after 2 years of treatment.

Practical update for the use of bone-targeted agents in patients with bone metastases from metastatic breast cancer or castration-resistant prostate cancer

Bone metastases are a significant source of morbidity and mortality for patients with breast and prostate cancer. In this review, we discuss key practical themes regarding the use of bone-targeted agents (btas) such as bisphosphonates and denosumab for managing bony metastatic disease. The btas both delay the onset and reduce the incidence of skeletal-related events (sres), defined as any or all of a need for radiation therapy or surgery to bone, pathologic fracture, spinal cord compression, or hypercalcemia of malignancy. They have more modest benefits for pain and other quality-of-life measures. Regardless of the benefits of btas, it should always be remembered that the palliative management of metastatic bone disease is multimodal and multidisciplinary. The collaboration of all disciplines is essential for optimal patient care. Special consideration is given to these key questions: ■ What are btas, and what is their efficacy?■ What are their common toxicities?■ When should they be initiated?■ How do we choose the appropriate bta?■ What is the appropriate dose, schedule, and duration of btas?

Bone-targeted therapy use in patients with bone metastases from lung cancer: A systematic review of randomized controlled trials

BACKGROUND

Patients with advanced lung cancer commonly have bone metastases. Compared with other malignancies, the use of bone-targeted agents (e.g. bisphosphonates and denosumab) is less common in lung cancer patients. This may be due to the perception that bone-targeted agents are less effective in this population.

OBJECTIVE

To perform a systematic review to evaluate data from randomized trials of bone-targeted agents in lung cancer patients with bone metastases.

METHODS

A systematic search of Medline, Embase and the Cochrane Register of Controlled Trials through May 2015 was performed. Randomized trials of bone-targeted therapies in lung cancer patients with bone metastases were sought. Outcomes studied included skeletal related events (SREs), pain, quality of life, progression-free survival and overall survival. Random effects meta-analyses were planned if studies were judged homogeneous.

RESULTS

Of 632 abstracts, 17 publications describing 13 studies were included. Sample sizes ranged between 50 and 1776. Of 3379 patients, 1903 had lung cancer, with subgroup data available for 8 of 13 studies. Patient demographics were comparable, but enrollment criteria and endpoints were heterogeneous across studies, precluding meta-analysis. Study-specific results suggested that bone-modifying agents reduce the incidence of SREs and bone pain in lung cancer patients. Three studies suggested a survival benefit.

CONCLUSION

Data from included trials suggests benefit of bone-targeted agents in lung cancer for the prevention of SREs and bone pain. There is a trend toward improvement in overall survival and progression-free survival, although further research is needed. Impact on quality of life and key subgroups for benefit both require future research.

Future directions for bone metastasis research - highlights from the 2015 bone and the Oncologist new updates conference (BONUS)

In an era of reduced peer-reviewed grant funding, performing academic bone oncology-related research has become increasingly challenging. Over the last 10 years we have held an annual meeting to bring together clinicians, clinician/scientists and basic biomedical researchers interested in the effects of cancer and its treatment on skeletal tissues. In the past these "Bone and the Oncologist New Updates Conference (BONUS)" meetings have served as critical catalyst for initiating productive research collaborations between attendees. The 2015 BONUS meeting format focused on potential key research themes that could form the basis of a coordinated national research strategy to tackle unmet clinical and research needs related to complications associated with cancer metastasis to bone. The three themes planned for discussion were: Is bone metastases-related pain the main issue facing patients? Are there new therapeutic targets for patients with bone metastases? How do we more firmly link basic science with clinical practice? We present a summary of lectures and commentaries from the attendees to serve as an example that other similarly motivated groups can model and share their experiences. It is our hope that these presentations will result in comments, feedback and suggestions from all those researchers interested in this important area.

RANKL/RANK interaction promotes the growth of cervical cancer cells by strengthening the dialogue between cervical cancer cells and regulation of IL-8 secretion

Receptor activator for nuclear factor κB ligand (RANKL) is a member of the tumor necrosis factor (TNF) family. The interaction between RANKL and its receptor RANK plays an important role in the development and function of diverse tissues. However, the expression and role of RANKL in cervical cancer are still unknown. In the present study, we found that RANKL and RANK were highly co-expressed in cervical cancer. HeLa and SiHa cells secreted soluble RANKL (sRANKL), expressed member RANKL (mRANKL) and RANK. Recombinant human RANKL protein had no effect on the viability of HeLa and SiHa cells. Yet, blocking RANKL with an anti-human RANKL neutralizing antibody (α-RANKL) or recombinant human osteoprotegrin (OPG) protein resulted in the downregulation of Ki-67 and B-cell lymphoma 2 (Bcl-2) expression and an increase in Fas and Fas ligand (FasL) expression, as well as a high level of viability and a low level of apoptosis in the HeLa and SiHa cells. In addition, α-RANKL led to a decrease in IL-8 secretion. Recombinant human IL-8 protein reversed the effect of α-RANKL on the expression of proliferation- and apoptosis‑related molecules, and proliferation and apoptosis in the HeLa and SiHa cells. The present study suggests that a high level of mRANKL/RANK expression in cervical cancer lesions plays an important role in the rapid growth of cervical cancer cells possibly through strengthening the dialogue between cervical cancer cells and regulation of IL-8 secretion, which may be a possible target for cervical cancer therapy.

The incidence and clinical impact of bone metastases in non-small cell lung cancer

INTRODUCTION

Non-small cell lung cancer (NSCLC) is the leading global cause of cancer death. While bone metastases (BM) commonly cause morbidity, bone-targeted agent (BTA) use is variable. We investigated the incidence and impact of BM among unselected NSCLC patients.

METHODS

A retrospective chart review of all NSCLC patients seen at a single institution from January 2007 to January 2008 was performed. Various clinical and pathology data were collected. In BM patients, skeletal related events (SRE), interventions and outcomes were recorded.

RESULTS

We identified 383 patients; median age 68 (IQR 60-76); 54% female. Initially 156 patients (41%) were treated with curative intent of whom 91 subsequently relapsed; 227 (59%) were considered palliative from time of diagnosis, including 22 with early stage disease not amenable to radical therapy. Of 296 patients with advanced NSCLC, common metastatic sites were: lung/pleura (80%), mediastinal nodes (69%), bone (39%), brain (30%), and liver (24%). Of 118 patients with BM, 69 (59%) had ≥1 SREs (range 1-18). Common SREs were radiotherapy (63%), pathologic fractures (22%), spinal cord compression (6%) or surgery to bone (5%). Opioid analgesia was required in 69% of BM patients, only 6% of patients with BM received BTA. Overall survival (OS) in pts with mNSCLC was 7.3 months (IQR 3.1-20.5). Pts with BM had significantly shorter OS compared to those without BM (5.8 versus 10.2 months, p=0.03).

CONCLUSIONS

BM are common in patients with advanced NSCLC and associated with shorter survival. In this cohort, despite SREs occurred in many patients, BTA were rarely used.

A phase II, multicentre trial evaluating the efficacy of de-escalated bisphosphonate therapy in metastatic breast cancer patients at low-risk of skeletal-related events

The optimal frequency of intravenous (IV) bisphosphonate administration is unclear. We thus performed a study evaluating the effects of switching from 3–4 to 12 weekly therapy in patients with biochemically defined low-risk bone metastases. Patients with serum C-telopeptide (CTx) levels ≤600 ng/L after ≥3 months of 3–4 weekly IV pamidronate were switched to 12 weekly therapy for 48 weeks. Primary endpoint was the proportion of patients maintaining CTx levels in the lower-risk range. All endpoints (serum CTx and bone-specific alkaline phosphatase (BSAP), skeletal-related events (SREs) and self-reported pain) were measured at baseline, 6, 12, 24, 36 and 48 weeks. Treatment failure was defined as biochemical failure (CTx > 600 ng/L) or a SRE. Exploratory biomarkers including; serum TGF-β, activin-A, bone sialoprotein (BSP), procollagen type 1 N-terminal propeptide and urinary N-telopeptide (NTx) were assessed at baseline as predictors for failure to complete treatment. Seventy-one patients accrued and 43 (61 %) completed 48 weeks of de-escalated therapy. Reasons for failure to complete treatment included; biochemical failure (CTx > 600 ng/L) (n = 10, 14.1 %), on-study SRE (n = 9, 12.7 %), disease progression (n = 7, 9.9 % including death from disease [n = 1, 1.4 %]) or patient choice (n = 2, 2.8 %). Elevated baseline levels of CTx, BSAP, NTx and BSP were associated with treatment failure. The majority of patients in this biochemically defined low-risk population could switch from 3–4 weekly to 12 weekly bisphosphonate therapy with no effect on CTx levels or SREs during the 48 week study. Larger trials are required to assess the roles of biomarkers as predictors of adequacy of de-escalated therapy.

Incidence, consequences and treatment of bone metastases in breast cancer patients-Experience from a single cancer centre

Background

There is a paucity of literature about the benefits of bone-targeted agents for breast cancer patients with bone metastases treated in the non-trial setting. We explored the incidence, consequences, and treatment of bone metastases at a single cancer centre.

Methods

Electronic records of metastatic breast cancer patients were reviewed and pertinent information was extracted.

Results

Of 264 metastatic breast cancer patients, 195 (73%) developed bone metastases. Of these patients, 176 were eligible for analysis. Median age at bone metastases diagnosis was 56.9 years (IQR 48–67) and initial presentation of bone metastases included asymptomatic radiological findings (58%), bone pain (40%), or a SRE (12.5%). Most patients (88%) received a bone-targeted agent, starting a median of 1.5 months (IQR 0.8–3.30) after bone metastasis diagnosis. 62% of patients had ≥1 SRE. The median time from bone metastasis diagnosis to first SRE was 1.8 months (IQR 0.20–8.43 months). Median number of SREs per patient was 1.5 (IQR 0–3). Overall, 26.8% of all SREs were clinically asymptomatic. Within the entire cohort, 51% required opioids and 20% were hospitalized due to either an SRE or bone pain.

Conclusions

Despite extensive use of bone-targeted agents, the incidence of SREs remains high. Nearly half of SREs occur prior to starting a bone-targeted agent. Use of opioids and hospitalizations secondary to bone metastases remain common. More effective treatment options are clearly needed.

Comparing cost-effectiveness analyses of denosumab versus zoledronic acid for the treatment of bone metastases

BACKGROUND

Bone metastases from various cancers have been traditionally treated with bisphosphonates, such as zoledronic acid (ZA), to prevent future skeletal-related events (SREs). Denosumab (Dmab) has been shown to have more advantages in preventing SREs in clinical trials than ZA, but the cost to administer Dmab is significantly higher.

METHODS

A literature review was conducted to investigate the methodologies used to compare the cost-effectiveness of Dmab and ZA. MEDLINE and EMBASE were searched systematically for all cost-effectiveness analyses published between January week 1, 2006 to August week 1, 2012. Search strategies were designed to retrieve articles analyzing the cost-effectiveness and cost utility of Dmab compared to ZA in patients with bone metastases. From 12 references obtained in the initial database search, eight satisfied the predetermined criteria for full article review. Articles were analyzed for incremental costs per skeletal-related event avoided or incremental cost per quality-adjusted life year gained.

RESULTS

All the studies identified received funding from Novartis Pharmaceuticals (the manufacturer of ZA) or Amgen Incorporated (the manufacturer of Dmab). The studies looked at the economic analysis using different associated costs and over various time periods, ranging from a 1-year to a lifetime time horizon.

CONCLUSION

It is not clear whether the methods used across studies are consistent, which may account for the differences between estimated costs and effects. Future research is suggested to explore the cost-effectiveness between Dmab and ZA using a standardize time frame and endpoint.

Denosumab versus zoledronic acid for treatment of bone metastases in men with castration-resistant prostate cancer: a cost-effectiveness analysis

OBJECTIVE

Denosumab has been approved in the US for skeletal-related event (SRE) prevention in bone-metastatic prostate cancer on the basis of a phase III clinical trial in which denosumab reduced SREs relative to zoledronic acid. Overall survival, disease progression, and serious adverse events did not differ significantly between groups. This analysis assessed the cost-effectiveness of denosumab vs zoledronic acid in bone-metastatic prostate cancer from a US payer perspective.

METHODS

A literature-based Markov model, wherein inputs were selected to reproduce clinical trial outcomes, was developed to estimate the survival, quality-adjusted life-years (QALYs), number and costs of SREs, and drug and administration costs for patients receiving denosumab or zoledronic acid over 27 months. QALYs were estimated by assigning health-state utilities. SRE-related costs and utilities were literature-based. Outcomes were discounted 3% per annum, and model robustness was tested via scenario, univariate, and probabilistic sensitivity analyses.

RESULTS

Denosumab resulted in fewer estimated SREs (-0.241; 1.036 vs 1.277), more QALYs (0.0074; 0.9306 vs 0.9232), and lower SRE-related costs (-$2340; $8824 vs $11,164), but higher drug-related costs ($10,181; $23,144 vs $12,963) and total costs ($7841; $31,968 vs $24,127) vs zoledronic acid. The base case estimated cost per QALY-gained was $1,058,741.

CONCLUSION

This analysis was limited by the restricted availability of clinical data and the need to use projection methods beyond the trial time frame. However, a wide range of scenarios predicted denosumab to have an incremental cost/QALY gained above what may be considered acceptable value for money in the US. This raises important questions regarding the pharmacoeconomic value of denosumab in bone-metastatic prostate cancer.

Efficacy and safety of denosumab for the treatment of bone metastases in patients with advanced cancer

Bone metastases are known to be caused by all types of cancer. Cancer metastasis to bone has been said to considerably compromise patients' quality of life and adversely affect lifetime prognosis. Although progress in cancer treatment has prolonged survival significantly, this may make increased numbers of patients suffer from bone metastases. Until now, as for the treatment of bone metastases, local therapies, including radiation therapy and surgery, were performed mainly as palliative therapies. However, bisphosphonate-based therapies have recently become available and are frequently administered to delay or prevent skeletal-related events, which include pathologic bone fracture, spinal cord compression, radiologic treatment for bone lesions, surgical procedures for bone lesions and hypercalcemia. Moreover, denosumab, the first fully human monoclonal antibody to receptor activator of nuclear factor κ-B ligand, was approved in the USA because of its evidence-supported clinical effects. Denosumab was effective for prolonging the time to skeletal-related events and inhibiting the onset of pain via the suppression of osteoclast activation. Denosumab has been shown to have a greater effect compared with zoledronic acid, most notably in patients with breast or prostate cancer. In this article, the efficacy and safety of denosumab for the treatment of bone metastases in patients with various advanced cancers are discussed.

Health-economic review of zoledronic acid for the management of skeletal-related events in bone-metastatic prostate cancer

Zoledronic acid is the only bisphosphonate approved for the prevention or delay of skeletal-related events in patients with bone metastases secondary to prostate cancer. Recently, the US FDA and the EMA approved denosumab (a fully human monoclonal antibody) to treat skeletal-related events in bone-metastatic prostate cancer. This article summarizes the cost-effectiveness literature pertaining to these two agents when used in the prevention of skeletal-related events secondary to malignancy. Zoledronic acid (and denosumab in comparison with zoledronic acid) have been found to be cost effective and cost ineffective depending on the analytical perspective and model parameters.

The European Multidisciplinary Cancer Congress (ECCO 16, ESMO 36 and ESTRO 30)

“Integrating basic and translational science, surgery, radiotherapy, medical oncology, and care” was the mission statement of the 2011 European Multidisciplinary Cancer Congress, which was held in Stockholm, Sweden, on 23–27 September 2011.