Treatment of multiple myeloma with nasal spray calcitonin: a histomorphometric and biochemical study

Expression and function of the calcitonin receptor by myeloma cells in their osteoclast-like activity in vitro

Malignant plasma cells exert osteoclast-like activity in vitro. We investigated the function of the calcitonin (CT) receptor (R) on myeloma cells from patients and in myeloma cell lines. Primary myeloma cells expressed high CTR levels whereas the cell lines uniformly exposed the CTR-2 variant expressed by osteoclasts. Treatment of myeloma cell lines with CT modified the intracellular Ca(2+) and cAMP levels, suggesting the activation of both PKC and PKA pathways, and abrogated their bone resorptive property as erosive pits on osteologic substrates. Thus, the expression, sensitivity and function of CTR-2 in myeloma cells emphasize their osteoclast-like behavior in vitro.

Use of calcitonin for the treatment of an odontoid fracture. Case report

The authors report on the efficacy of nonsurgical treatment of an older patient with a fractured odontoid process. The patient, an 85-year-old woman, had multiple medical problems that put her at an increased surgery-related risk. Therefore, an alternative approach was elected, including immobilization with a Philadelphia collar and the provision of calcitonin nasal spray. Bone union and clinical recovery were achieved within 8 weeks of initiating the nasal calcitonin therapy (12 weeks postinjury). Considering the patient's age, comorbidities, and the severity of the fracture, the recovery period was unusually short. The authors believe that calcitonin played a pivotal role in the healing process of the fractured odontoid bone. There is no question that the fusion in this patient could be unrelated to the medical therapy. This description of one patient, as well as the lack of a large randomized study, precludes any scientific conclusions. Nevertheless, the authors believe that the development of a successful fusion in this high-risk patient should be reported as an observation that merits confirmation and study. The authors also discuss the physiological effects of calcitonin and the research and clinical experience with this hormone in different conditions affecting bone.

Use of Bisphosphonates in the Treatment of Multiple Myeloma

Bone pain is the single most common presenting complaint in myeloma. Although first-line chemotherapy has a marked effect on bone pain, skeletal disease frequently continues to progress throughout the course of the disease and the incidence of skeletal events remains high. The underlying pathology in myeloma constitutes mainly increased osteoclastic activity but also reduced osteoblastic activity. Any agent that inhibits osteoclast activity potentially provides some degree of skeletal protection although only the bisphosphonates have achieved widespread use. Bisphosphonates are potent inhibitors of osteoclast-mediated bone resorption and evidence of bone protection and modification of skeletal disease progression has been greatest with clodronate and pamidronate. The MRC VIth Myeloma Trial is, to date, by far the largest randomised placebo-controlled trial of bisphosphonates in myeloma. Current evidence suggests that bisphosphonate treatment should begin as early as possible and continue indefinitely, and probably should be considered for all patients with myeloma. The additional costs of clodronate therapy in the management of myeloma patients were around 17% higher than in controls which is moderate when considering the significant reductions in hypercalcaemic episodes and in vertebral and non-vertebral fractures.

Methylated beta-cyclodextrins are able to improve the nasal absorption of salmon calcitonin

The absorption enhancing effect of methylated beta-cyclodextrins on the nasal absorption of salmon calcitonin (sCT) was studied in rats and rabbits. The nasal absorption of sCT following administration without additives was low in both species. The absorption in rats could be largely improved by coadministration of cyclodextrins as apparent from the effect on serum calcium concentrations. Trimethyl-beta-cyclodextrin (TM beta CD), at a concentration of 5% (w/v), was the least potent enhancer. Randomly methylated-beta-cyclodextrin (RM beta CD) and dimethyl-beta-cyclodextrin (DM beta CD), all at a concentration of 5% (w/v), were almost equally effective in decreasing serum calcium levels, and the hypocalcemic responses were similar to those of i.v. and s.c. injected sCT. Absorption enhancement was already achieved with 1% DM beta CD added to the nasal formulations. In rabbits, only the effect of DM beta CD on the nasal sCT absorption was investigated. A total serum calcium decrement in 4 hours of 9.4 +/- 3.9% (mean +/- SD) was observed following nasal administration of 12.6 IU/kg sCT with 5% DM beta CD, comparable to that of i.v.-injected sCT. In conclusion, the methylated cyclodextrins DM beta CD and RM beta CD are suitable absorption enhancers for nasal sCT administration, which is expected to have a clinical impact on the therapy with calcitonin.

Total and regional bone mineral content and fracture rate in postmenopausal osteoporosis treated with salmon calcitonin: a prospective study

Seventy-two postmenopausal osteoporotic women having more than one nontraumatic vertebral crush fracture were studied. Thirty-six of them, aged 68.8 +/- 1.2 years (18 +/- 4 YSM-years since menopause), were treated with 100 IU/day of salmon calcitonin i.m. plus 500 mg of elemental calcium for 10 days each month. The remaining 36 patients, aged 69.6 +/- 1.4 years (19 +/- 3 YSM), were given only 500 mg of elemental calcium for 10 days each month. All patients underwent clinical and analytical evaluation every 3 months. Radiological evaluation, assessment of vertebral deformities, and metacarpal radiogrammetry were done every 6 months. Densitometric measurements of total and regional bone mass were made every 12 months. At 24 months, the calcitonin group showed a 60% reduction in the number of new fractures and the group receiving only calcium had a 45% increase (P < 0.001). The incidence of vertebral fractures was 0.07 per patient-year in the group treated with calcitonin and 0.45 per patient-year in the group treated with calcium (P < 0.001). At 2 years, the calcitonin group showed a 12% increase in cortical bone mass on metacarpal radiogrammetry, a 16% increase in the axial skeleton on trunk densitometry, a 3.5% increase in total body bone mineral content, a 30.7% increase in pelvic bone mineral content, and a 6.2% increase in arm bone mineral content (all P < 0.001). In the group treated with calcium alone there was a loss of bone mass in every region. These findings suggest that salmon calcitonin is effective in the treatment of osteoporosis and show that it acts on cortical and trabecular bone.

Calcitonin in the Prevention and Therapy of Osteoporotic Syndromes

It is now generally accepted that estrogen status, exercise and adequate calcium intake are the singularly most important factors which guarantee the assumption of genetically programmed peak bone mass. Physicians also recognize that estrogen replacement therapy is not only essential to prevent bone loss in the early postmenopausal female, but also for the long-term preservation of bone mineral density. The efficacy of either continuous or intermittent calmon calcitonin administration in preventing further bone loss and in some instances decreasing fracture incidences in established osteoporotic syndromes is currently well established. As noted during a variety of controlled investigations performed both in the United States and abroad, and in the Physician's Resource Manual on Osteoporosis published by the United States National Osteoporosis Foundation, salmon calcitonin is also effective in early postmenopausal women who are not candidates for estrogen replacement therapy in addition to those patients with established osteoporosis. The practicing physician should acknowledge that of all the anti-resorptive agents recommended for therapy in osteoporotic syndromes, estrogens and salmon calcitonin are currently the only two drugs recommended by the U.S. Food and Drug Administration (USFDA) as safe and effective as treatment modalities in osteoporosis.

Biologic, histologic and densitometric effects of oral risedronate on bone in patients with multiple myeloma

Recent studies have shown that treatment with bisphosphonates could be effective against the myelomatous skeletal deterioration. However, the mechanisms of action of these drugs in multiple myeloma (MM) have been poorly studied. In the present study, 11 patients with MM and bone lesions were treated orally with 30 mg/day of risedronate for 6 months, and monitored for 6 additional months. Mean serum calcium decreased from day 4, with a concomitant increase in circulating levels of PTH (1-84) and 1,25-(OH)2D. These parameters reached their nadir on day 7 and returned to baseline value during the treatment period. Markers of bone resorption, pyridinoline and deoxypyridinoline decreased from day 7; they were at 50% and 78% of their basal value at the end of treatment and follow-up periods, respectively. A significant reduction of estimates of bone formation (serum alkaline phosphatase and osteoclacin) appeared at month 3 and persisted for the remainder of the 9-month period. Histomorphometric analysis showed a significant reduction of activation frequency, number of osteoclasts and erosion depth. Bone turnover was high at baseline, and normal after treatment, without mineralisation defects. Mean wall thickness was not different before and after treatment. Spinal bone mineral density measured by dual energy X-ray absorptiometry increased (5.3%) at the end of treatment. We conclude that oral risedronate in multiple myeloma induces a noticeable and rapid inhibition of bone resorption.

Bone changes in postmenopausal Spanish women

Total body bone mass (TBBM), axial bone mass (trunk = chest and spine), and peripheral bone mass (arms and legs) were determined in 258 normal, slow bone mass loser, postmenopausal women, as determined by previous biochemical studies, in order to study the degree of bone mass reduction due to menopause. The subjects of this study were divided into 5-year groups on a year-since-menopause basis. The first group corresponded to 1-5 years since menopause, and the last group to 25 years or over since menopause. An important and significant reduction in trunk bone mass (-12.3%, P < 0.001) and TBBD (-5.8%, P < 0.002), without changes in head, arms, and legs was observed in the first 5-year group. In the next 5-year group, a significant reduction was observed in all body areas, but at a higher rate in the peripheral skeleton (-9% in arms and -7.3% in legs). A slow down in bone mass loss was observed in the period between 10 and 25 years since menopause. These values became significant again after 25 years since menopause at the axial (-28.9%, P < 0.001) and TBBD (-20.3%, P < 0.05) level. Aside from providing percentages of bone mass reduction with respect to age and time since menopause, these data also indicate that measurements of specific body areas may not be extrapolated to others due to different loss in different body areas, and that there is a marked bone loss rate in the axial skeleton in the first 5 years since menopause.

Salmon calcitonin reduces vertebral fracture rate in postmenopausal crush fracture syndrome

The effectiveness of calcitonin on the vertebral fracture rate in postmenopausal osteoporosis was assessed through the skeletal deformity index (SDI) and the new vertebral fracture rate per 100 patient-years in a group of 32 women with postmenopausal osteoporosis treated by us with 100 IU of salmon calcitonin and 500 mg of elemental calcium for 10 consecutive days each month, and in another group of 28 women with postmenopausal osteoporosis treated with 500 mg of elemental calcium only for 10 consecutive days each month. Both groups were age-matched. The follow-up was a retrospective randomized study over 24 months. Thirty of the 32 women of the calcitonin group and 27 of 28 women of the calcium group finished treatment. The SDI was stabilized after six months in the calcitonin group (0.57 +/- 0.13, 0.62 +/- 0.18, 0.63 +/- 0.16 and 0.64 +/- 0.17, at base line, 6, 12 and 24 months respectively). The calcium group showed a significant increase only at 12 months (P less than 0.01) and 24 months (P less than 0.05) (0.61 +/- 0.16, 0.63 +/- 0.16, 0.69 +/- 0.16, and 0.73 +/- 0.15, at base line, 6, 12 and 24 months respectively). At 24 months, the new vertebral fracture rate decreased by 60% (20%, 14% and 8% at 6, 12 and 24 months respectively) in the calcitonin group and increased by 35% (31%, 33% and 42%, at 6, 12 and 24 months respectively) in the calcium group (P less than 0.025). These results show that calcitonin induced a significant reduction in postmenopausal osteoporotic vertebral fractures.

Intranasal salmon calcitonin. A review of its pharmacological properties and potential utility in metabolic bone disorders associated with aging

Salmon calcitonin, a polypeptide hormone secreted by the parafollicular C cells of the thyroid gland, lowers serum calcium levels by decreasing bone resorption and renal tubular calcium reabsorption. An analgesic action, possibly mediated via beta-endorphins, is also evident. In the past, parenteral formulations of salmon calcitonin have been used in the management of metabolic bone disorders, but their routine use has been limited by the inconvenience of this route of administration and by poor tolerability. The development of an intranasal preparation of salmon calcitonin will provide a more convenient means of administering the drug. In clinical trials published to date intranasal salmon calcitonin has been effective and well tolerated in small numbers of recently postmenopausal women at risk of developing osteoporosis, and in patients with established osteoporosis, Paget's disease, or osteoporosis secondary to corticosteroid usage, multiple myeloma or ovariectomy. For periods of up to 2 years the drug reduces bone resorption and improves bone architecture, relieves pain and increases functional status. Further research is needed to confirm longer term efficacy (in particular, effects on fracture rate), optimal dosage schedules and the role of intermittent and combination treatment regimens.

The measurement of osteoporosis in clinical practice

It has been reported that metacarpal morphometry does not correlate with iliac crest histomorphometry in patients with hip fractures. Such disagreement led us to study the correlation between both types of measurements on 35 patients who had suffered hip fracture. We observed a significant correlation between metacarpal morphometry and iliac crest cortical width (p less than 0.001), and to a lesser degree with the trabecular bone volume (p less than 0.01). The same was also true if we assessed separately the patients with cervical or trochanteric hip fractures.

Heterogeneity of osteoporotic syndromes and the response to calcitonin therapy

In the past, the osteoporotic syndrome has been variably classified as "senile," "postmenopausal," "involutional," "Type I," and "Type II," primarily on the basis of age, fracture incidence patterns, and/or fracture sites. Histological analyses of bone biopsy specimens from osteoporotic individuals also reveal a wide spectrum of cellular activity and rates of bone formation and resorption. These range from those that show an abundance of osteoblasts and osteoclasts with increments in both bone formation and bone turnover (i.e., "active" or "high-turnover" osteoporosis) to others demonstrating minimal cellular activity and relatively little active bone formation or resorption ("inactive" or "low-turnover" osteoporosis). The varied states of bone activity are reflected in associated changes in noninvasive biochemical markers of bone turnover such as circulating bone-gla-protein (BGP) or the urinary hydroxyproline/creatinine ratio (OH-Pr/Cr). Both BGP and OH-Pr/Cr are elevated in patients with high-turnover osteoporotic syndromes. The significance of this mode of categorizing osteoporotic patients is exemplified by the response to remedial therapy such as salmon calcitonin. Recent studies demonstrate a striking sensitivity of patients with high-turnover osteoporosis to calcitonin, with as much as 22% increments in vertebral bone mass recorded during a 12-month therapeutic interval. These promising results should also be compared with other forms of therapy in which an increase in vertebral bone mass of only 7-8% was sufficient to cause a significant decrease in the incidence of vertebral fracture rates.