Response of Paget's disease to porcine and salmon calcitonins: Effects of long-term treatment

Abstract

Multiple clinical, biochemical and immunologic variables were measured in 49 patients with Paget's disease during 4 to 41 months (mean, 25 months) of treatment with porcine (PCT) or synthetic salmon calcitonin (SCT) or both. Mild nausea and dermal reactions occurred in 20 per cent of the patients and were generally transient. Skeletal and radicular pain, and overt neurologic deficits were moderately to dramatically relieved in 75 per cent of the patients. Maximal clinical benefits were achieved during the first 6 to 12 months of treatment, with only one fifth of the patients experiencing intermittent exacerbations of pain during the 2nd and 3rd years of treatment. Three examples of dramatic roentgenologic improvement were observed. SCT doses of 50 MRC units three times a week generally were as effective as 100 MRC units three times a week or daily. Dissociation among the clinical effects, the decrease in serum alkaline phosphatase and the decrease in urinary hydroxyproline were common. Binding antibodies developed in 60 per cent of the patients treated with PCT and in 30 per cent of those treated with SCT; however, SCT-binding antibodies usually were present in higher titer and with a greater frequency of SCT neutralization activity. No correlations were present between the development of antibodies and the incidence of biochemical rebounds or the failure of increased doses of SCT to renew biochemical effects. No evidence of increased secretory activity of the parathyroid glands was observed in 10 patients with biochemical rebounds. These data demonstrate the feasibility and efficacy of continuous long-term therapy with calcitonin on an outpatient basis, and SCT may be the treatment of choice for Paget's disease.