Osteoporosis drug calcitonin linked to cancer risk
The European Medicines Agency (EMA) is the European equivalent of the US Food and Drug Administration (FDA). On July 19 the EMA announced that it had completed a review of the benefits and risks of calcitonin-containing medicines; it concluded that there was evidence of a small increased risk of cancer with long-term use of these medicines. Calcitonin is a hormone that increases the amount of calcium in the bones and lowers the calcium level in the blood.
The EMA’s Committee for Medicinal Products for Human Use (CHMP) recommended that they should only be authorized for short-term use for three conditions for which EMA approval had previously been granted: Paget’s disease (a chronic bone disease); acute bone loss due to sudden immobilization; and hypercalcemia (high blood level of calcium) caused by cancer. The agency also concluded that the benefits of calcitonin-containing medicines did not outweigh their risks in the treatment of osteoporosis and that they should no longer be used for this condition.
Calcitonin, also called calcitonin-salmon, is a synthetic copy of a polypeptide hormone secreted by the ultimobranchial gland of salmon. In the United States, two nasal-spray versions of calcitonin are FDA-approved for treating postmenopausal osteoporosis in women: Fortical (Upsher-Smith Laboratories) and Miacalcin (Novartis). The labels for both of these drugs does not cite either any restrictions regarding their use or a warning about the risk for cancer.
The EMA study included a review of available data from the companies that market these drugs, postmarketing safety data, randomized controlled studies, two studies of unlicensed oral calcitonin drugs, and experimental cancer studies. The investigators found that “a higher proportion of patients treated with calcitonin for long periods of time develop cancer of various types, compared with patients taking placebo.” The increase in cancer rates ranged from 0.7% for oral formulations to 2.4% for the nasal formulation. CHMP concluded that the benefits of calcitonin for osteoporosis did not exceed the risks. The committee noted that the spray’s only indication is for osteoporosis; therefore, it should be removed from the market.
In addition to banning its use for osteoporosis, the CHMP recommended that calcitonin should be administered for no more than four weeks to prevent acute bone loss resulting from sudden immobilization, and normally for no more than three months to treat Paget's disease. It did not specify a time frame for the short-term use of calcitonin for treating hypercalcemia caused by cancer.
Take home message:
In view of the EMA’s findings, it is only a matter of time before the FDA will issue a similar recommendation regarding calcitonin. Therefore, it would be prudent for US women using the substance to consult their physician regarding alternatives.
Reference: European Medicines Agency