Double-blind, randomised, placebo-controlled, dose-finding study of oral ibandronate in patients with metastatic bone disease.

BACKGROUND: Bisphosphonates are an important component of the treatment of metastatic bone disease but more potent, oral formulations are required to improve the effectiveness and convenience of treatment. An oral formulation of the new bisphosphonate, ibandronate (BM 21.0955) has recently been developed. PATIENTS AND METHODS: One hundred ten patients with bone metastases (77 breast, 16, prostate, 3 myeloma, 14 others) were recruited from a single institution to this double blind placebo-controlled evaluation of four oral dose levels (5, 10, 20 and 50 mg) of ibandronate. No changes in systemic anti-cancer treatment were allowed in the month before commencing treatment or during the study period. After an initial four-week tolerability phase, patients could continue on treatment for a further three months without unblinding; patients initially allocated to placebo received ibandronate 50 mg. The primary endpoint was urinary calcium excretion (UCCR). Bone resorption was also assessed by measurement of pyridinoline (Pyr), deoxypyridinoline (Dpd), and the N-terminal (NTX) and C-terminal (Crosslaps) portions of the collagen crosslinking molecules. RESULTS: Two patients did not receive any trial medication thus, 108 patients were evaluable for safety. Ninety-two patients were evaluable for efficacy. A dose dependent reduction was observed in both UCCR and collagen crosslink excretion. At the 50 mg dose level, the percentage reductions from baseline in UCCR, Pyr, Dpd, Crosslaps and NTX were 71%, 28%, 39%, 80% and 74% respectively. One or more gastrointestinal (GI) adverse events occurring in the first month of treatment were reported by six (30%), seven (33%), nine (39%), nine (41%) and eleven (50%) patients at the placebo, 5, 10, 20 and 50 mg dose levels respectively. One patient (20 mg dose) developed radiographically confirmed oesophageal ulceration. GI tolerability may have been adversely affected by concomitant administration of non-steroidal anti-inflammatory agents. Nine (8%) patients stopped treatment within the first month due to GI intolerability but these patients were evenly distributed across the five treatment groups. There was no difference in non-GI adverse events between groups. CONCLUSIONS: Oral ibandronate has potent effects on the rate of bone resorption at doses which are generally well tolerated. Further development is appropriate to evaluate the effects of long-term administration in the prevention of metastatic bone disease and the management of established skeletal metastases.

High dose pamidronate: clinical and biochemical effects in metastatic bone disease.

Eighty-six patients with heavily pretreated progressive bone metastases (52 with breast carcinoma, 17 with prostate carcinoma, and 17 others) were included in 2 studies designed to assess the clinical and biochemical effects of a single 120 mg, 2-hour infusion of pamidronate. No other systemic anticancer treatment or radiotherapy were administered. Pamidronate had a significant beneficial effect, with a reduction in a symptom score measuring pain, World Health Organization performance status, and analgesic consumption and improvement in quality of life when compared with a placebo infusion. Symptomatic improvement corresponded with changes in the rate of bone resorption as indicated by the concentrations of pyridinoline crosslinks in the urine. In patients with the highest rates of bone resorption (N-terminal peptide-bound portion of the collagen crosslink or crosslaps excretion > or = twice that of normal) clinical response or normalization of the rate of bone resorption were rarely observed, with all clinical responses occuring in those patients with bone resorption rates of < twice that of normal. Intriguingly, symptomatic response also correlated with a modest (> 10%) fall in tumor marker levels, suggesting a possible effect of bisphosphonates on tumor activity.

Relationships between biochemical and symptomatic response in a double-blind randomised trial of pamidronate for metastatic bone disease.

PURPOSE: The aim of this study was to evaluate pamidronate for bone pain in a randomised double-blind trial and to evaluate the contribution of new markers of bone resorption in patients with bone metastases. PATIENTS AND METHODS: Fifty-two patients with painful bone metastases were randomised to receive a two-hour infusion of pamidronate 120 mg or an identical infusion of saline. Four weeks later, all patients received pamidronate 120 mg. Bone resorption markers measured included urinary calcium (uCa), hydroxyproline (Hyp), and the collagen breakdown products: NTx, Crosslaps and Free Dpd. RESULTS: Symptomatic response during the first four weeks was seen after pamidronate, but not with placebo (P < 0.05). Quality of life was maintained with pamidronate and deteriorated after placebo (P < 0.05). Resorption markers did not decrease after placebo, but NTx and Crosslaps both decreased by 70% after pamidronate (P = 0.001). A second infusion of pamidronate did not decrease resorption further, but maintained the suppression of resorption at similar levels for a further four weeks. Symptomatic response to pamidronate correlated closely with the rate of bone resorption; it was more frequent in those patients with an initial NTx value of < 2 times the upper limit of normal (17 of 27, 62%) and in those where the level of Ntx returned to normal (19 of 32, 59%), than in the patients with either high baseline values of NTx (> 2 times the upper limit of normal) or Ntx levels which failed to normalise for whom the response frequencies were 2 of 16 (13%) and 0 of 11 (0%), respectively. CONCLUSIONS: Subjective benefit after intravenous pamidronate is confirmed in this placebo-controlled study. The new bone resorption markers of collagen breakdown were able to predict clinical response to pamidronate.

The future of bisphosphonates in cancer.

Bisphosphonates, in conjunction with rehydration, are now the treatment of choice for hypercalcaemia of malignancy. They can also relieve bone pain and improve quality of life as single agent therapy and, in conjunction with systemic anticancer treatments, can prevent skeletal complications and slow down the metastatic process. The clinical effects are greatest and most clearly defined in breast cancer and multiple myeloma, but, theoretically, clinical benefit should be achievable across the entire spectrum of metastatic bone disease. The new biochemical markers for measuring bone resorption are for the first time providing a direct assessment of the effects of treatment on bone. It is hoped that they will enable a more scientific selection of the type, dose and schedule of bisphosphonate required for the best compromise between efficacy, convenience and patient acceptability. We can expect to see a rapid increase in the use of bisphosphonates in malignancy (especially breast cancer and myeloma). Careful assessment of the health-care economics of this new treatment modality is urgently needed.