Evaluation of the clinical benefit of long-term (beyond 2 years) treatment of skeletal-related events in advanced cancers with zoledronic acid

Randomized phase II study of zoledronate dosing every four versus eight weeks in patients with bone metastasis from lung cancer (Hanshin Cancer Group0312)

BACKGROUND

Zoledronic acid (ZA) reduces the incidence of skeletal-related events (SREs) in patients with bone metastases from solid tumors. However, the optimal dosing interval of ZA for patients with lung cancer is uncertain.

METHODS

We conducted a randomized, open-label, feasibility phase 2 trial at eight Japanese hospitals. Patients with bone metastases from lung cancer were randomly assigned to receive either 4 mg of ZA every four weeks (4wk-ZA) or every eight weeks (8wk-ZA). The primary endpoint was the time to the first SRE and the rate and types of SREs after one year. SREs were defined as pathologic bone fracture, bone radiation therapy or surgery, and spinal cord compression. Secondary endpoints were the SRE incidence at six months, pain assessment, changes in analgesic consumption, serum N-telopeptide, toxicity, and overall survival.

RESULTS

Between November 2012 and October 2018, 109 patients were randomly assigned to the 4wk-ZA group (54 patients) and the 8wk-ZA group (55 patients). The number of patients who received chemotherapy or molecular-targeted agents was 30 and 23 and 18 and 16 in the 4wk-ZA and 8wk-ZA groups, respectively. The median time to the first SRE could not be calculated because of a low SRE. The time to the first SRE of all patients did not differ between the groups (P = 0.715, HR = 1.18, 95% CI = 0.48, 2.9). The SRE rate of all patients after 12 months was 17.6% (95% CI = 8.4, 30.9%) in the 4wk-ZA and 23.3% (95% CI = 11.8, 38.6%) in the 8wk-ZA group, without significant differences between the groups. There was no difference in any secondary endpoint between groups, and these endpoints did not differ among treatment modalities.

CONCLUSIONS

An eight-week ZA interval does not increase the SRE risk for patients with bone metastasis from lung cancer and could be considered clinically.

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.

Safety and Efficacy of Long-Term Zoledronic Acid in Advanced Breast Cancer with Bone Metastasis in South China

Background

This retrospective study aimed to characterize the long-term (>24 months) safety profile of zoledronic acid (ZA). We aimed to investigate whether long-term ZA treatment had greater benefits than short-term treatment in patients from southern China with advanced breast cancer (ABC) with bone metastasis. Patients and Methods. A total of 566 metastatic breast cancer cases were included and divided into two groups according to the duration of ZA treatment. The included patients had at least one lytic bone lesion and had no skeletal-related events (SREs) prior to ZA therapy. The primary endpoint was to analyze the safety and long-term adverse effects, which covered osteonecrosis of jaws (ONJ), renal impairment, and hearing impairment. The second objective was to determine the efficacy of long-term ZA treatment by the incidence of SREs.

Results

Fifteen patients were diagnosed with ONJ (2.7%): nine in the short-term group (3.1%) and six in the long-term group (2.2%, P = 0.606). Five cases (0.9%) had renal function impairment: two in the short-term group (0.7%) and four in the long-term group (1.1%, P = 0.676). One patient (0.2%) in the long-term group had hearing impairment after 23 months of ZA treatment (0.4%, P = 0.482). In total, 103 cases in the short-term group (35.2%) and 138 cases in long-term group (50.5%) developed SREs (P < 0.001). The mean annual SRE rate was 0.3 in the short-term group (range, 0-3.1) versus 0.2 in the long-term group (0-1.0, P = 0.269). Subgroup analysis suggested that cases with non-load-bearing bone involvement and those who received systematic anticancer therapy without chemotherapy might benefit from long-term ZA treatment. Cox regression analysis indicated poor performance status, and nonvisceral organ involvement predicted high risk for SRE.

Conclusions

The extension of ZA treatment did not increase the long-term adverse events and reduced the annual incidence of SREs beyond 24 months. Although longer treatment of ZA over 24 months appeared to be safe, further prospective investigation is required.

Long-term impact of bone-modifying agents for the treatment of bone metastases: a systematic review

PURPOSE

Bone-modifying agents (BMAs) for bone metastases are commonly prescribed for many years even though randomized clinical trials are only 1-2 years in duration. A systematic review on the risk-benefit of BMA use for > 2 years in breast cancer or castrate-resistant prostate cancer was conducted.

METHODS

MEDLINE, Embase, and Cochrane databases were searched (1970-February 2019) for randomized and observational studies, and case series reporting on BMA efficacy (skeletal-related events and quality of life) and toxicity (osteonecrosis of the jaw, renal impairment, hypocalcemia, and atypical femoral fractures) beyond 2 years.

RESULTS

Of 2107 citations, 64 studies were identified. Three prospective and 9 retrospective studies were eligible. Data beyond 2 years was limited to subgroup analyses in all studies. Only one study (n = 181) reported skeletal-related event rates based on bisphosphonate exposure, with decreased rates from 27.6% (0-24 months) to 15.5% (> 24 months). None reported on quality of life. All 12 studies (denosumab (n = 948), zoledronate (n = 1036), pamidronate (n = 163), pamidronate-zoledronate (n = 522), ibandronate (n = 118)) reported ≥ 1 toxicity outcome. Seven bisphosphonate studies (n = 1077) and one denosumab study (n = 948) reported on osteonecrosis of the jaw. Across three studies (n = 1236), osteonecrosis of the jaw incidence ranged from 1 to 4% in the first 2 years to 3.8-18% after 2 years. Clinically significant hypocalcemia ranged from 1 to 2%. Severe renal function decline was ≤ 3%. Atypical femoral fractures were rare.

CONCLUSIONS

Evidence informing the use of BMA beyond 2 years is heterogeneous and based on retrospective analysis. Prospective randomized studies with greater emphasis on quality of life are needed.

PROSPERO REGISTRATION NUMBER

CRD42019126813.

Bisphosphonates: AHFS 92:24

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Prolonged Use of Zoledronic Acid (4 Years) Did Not Improve Outcome in Multiple Myeloma Patients

BACKGROUND

Bisphosphonates, especially zoledronic acid (ZA), show antitumor effects in multiple myeloma (MM) and other neoplasms. The standard time for ZA administration has been 2 years. However, with improvement in overall survival (OS) in MM with new agents, it unclear whether ZA could be administered for a prolonged time to improve OS.

PATIENTS AND METHODS

A total of 170 patients with untreated, symptomatic MM were randomly divided into a group to receive ZA for 4 years, with a control group to receive ZA for 2 years. All patients were treated with the same induction therapy and stem-cell transplantation.

RESULTS

Actuarial curves at 5 years, showed that progression-free survival was 75% (95% confidence interval [CI], 64%-82%) and OS was 68% (95% CI, 60%-76%) in the 4-year group, which was not statistically significantly different compared with the control group: 72% (95% CI, 62%-78%) and 68% (95% CI, 60%-75%; P = .67). However, the 4-year group showed reduced skeletal events (21% occurrence rate); this was statistically significant compared with the control group: 43% (P < .001).

CONCLUSION

Although ZA did not improve OS in patients with MM; it continued to be useful to reduce skeletal events, and thus improve better quality of life for patients.

Legal liability in bisphosphonate-related osteonecrosis of the jaw

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is an adverse reaction that may occur in patients administered with bisphosphonates (BP). This condition can cause high morbidity and hinder quality of life. Its treatment is complex and often unsatisfactory, and prevention strategies may have limited effectiveness, if any. Thus, managing patients treated with BP may result in exposure of the practitioner to legal liability or malpractice claims: legal actions pursuant to BRONJ are reported to be underway on three continents. Nonetheless, the attribution of liability, if any, is a complex process requiring, on the basis of current knowledge, a robust and pragmatic approach to the facts, which must be identified from the point of view of the time, place and individuals involved. This means a comprehensive consideration of the sequence of actions from bisphosphonates prescription to BRONJ occurrence (as well as immediately after, and any action potentially related to its causation or worsening) is required in order to determine if a breach in informing, diagnosing, managing or referring the patient took place, as well as determining if the patient was compliant in attending to prescriptions and follow-up programmes.

Comparison of the anti-tumor effects of denosumab and zoledronic acid on the neoplastic stromal cells of giant cell tumor of bone

Denosumab and Zoledronic acid (ZOL) are two antiresorptive drugs currently in use for treating osteoporosis. They have different mechanisms of action but both have been shown to delay the onset of skeletal-related events in patients with giant cell tumor of bone (GCT). However, the anti-tumor mechanisms of denosumab on the neoplastic GCT stromal cells remain unknown. In this study, we focused on the direct effects of denosumab on the neoplastic GCT stromal cells and compared with ZOL. The microscopic view demonstrated a reduced cell growth in ZOL-treated but not in denosumab-treated GCT stromal cells. ZOL was found to exhibit a dose-dependent inhibition in cell growth in all GCT stromal cell lines tested and cause apoptosis in two out of three cell lines. In contrast, denosumab only exerted a minimal inhibitory effect in one cell line and did not induce any apoptosis. ZOL significantly inhibited the mRNA expression of receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG) in two GCT stromal cell lines whereas their protein levels remained unchanged. On the contrary, denosumab did not regulate RANKL and OPG expression at both mRNA and protein levels. Moreover, the protein expression of Macrophage Colony-Stimulating Factor (M-CSF), Alkaline Phosphatase (ALP), and Collagen α1 Type I were not regulated by denosumab and ZOL either. Our findings provide new insights in the anti-tumor effect of denosumab on GCT stromal cells and raise a concern that tumor recurrence may occur after the withdrawal of the drug.

Is retention of zoledronic acid onto bone different in multiple myeloma and breast cancer patients with bone metastasis?

Zoledronic acid (Zol) is used to treat bone disease in both multiple myeloma (MM) and breast cancer patients with bone metastasis (BC). However, bones of MM and BC patients show a difference in retention of the bisphosphonate used for bone scintigraphy. Therefore, we hypothesized that disease-specific factors may differently influence Zol retention in MM and BC patients. We tested this hypothesis in an investigator initiated phase II clinical trial in which we compared the whole-body retention (WBrt) of Zol in a cohort of 30 multiple myeloma (MM) and 30 breast cancer (BC) (20 Zol naive and 40 with six or more previous administrations). On average, 62% of the administered Zol was retained in the skeleton of both MM and BC patients and independently of the number of treatments. WBrt of Zol did not correlate with cross-linked C-telopeptide (CTX) levels, but linear regression analyses showed that WBrt of Zol correlated with bone-specific alkaline phosphatase (bALP) levels in BC (p = 0.001), and with CTX/bALP in Zol naive MM patients (p = 0.012). Especially in BC patients, WBrt correlated with age (p = 0.014) independently of kidney function. In MM patients WBrt was found to primarily correlate with the extent of bone disease (p = 0.028). Multivariate linear regression analyses of the entire cohort pointed out that WBrt of Zol was best predicted by age (p < 0.000), osseous lesions (p < 0.001), and the preceding Zol dosing (p < 0.005) (r(2)  = 0.97). Comparing bone scintigrams with CT/X-ray images showed a poor correlation between sites of active bone disease and binding of scintigraphy bisphosphonate in 36% of MM patients and in 13% of BC patients. We conclude that WBrt of Zol is primarily determined by two non-disease related factors and only one disease related, but that there may be differences in retention or drug delivery at individual sites of bone disease between MM and BC patients. In order to find the optimal dosing of Zol, these observations should be taken into account.