| Hyperparathyroidism |
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The parathyroid glands secret the parathyroid hormone (PTH) which plays an important role in regulating the concentration of calcium in the blood (calcemia). When this falls, the secretion of PTH increases to counterbalance the hypocalcaemia by stimulating the mobilization of calcium from reserves in bones and by increasing the reabsorption of calcium by the kidneys. This mechanism functions little or not at all, in the event of chronic renal insufficiency, which leads to persistent hypocalcaemia, which an increase and prolonged secretion of PTH tries to fight against at the expense of the bones’ mineral load. This pathological situation, which is called secondary hyperparathyroidism due to renal insufficiency, has harmful effects on the skeleton, and requires treatment. Natural vitamin D derivatives like calcitriol, or chemically optimized vitamin D derivatives like paricalcitol or doxercalciferol, have demonstrated their effectiveness when taken intravenously or orally, by reducing the level of PTH by direct inhibitory action on the parathyroid glands and indirectly by stimulating the absorption of alimentary calcium by the intestines. This external, additional contribution of calcium relieves the internal mobilization of the bones’ reserves. Inecalcitol is a derivative of calcitriol. It has less of an impact on the calcium’s metabolism, but its direct effect on the secretion of PTH has never been investigated. The inecalcitol may be able to be used in secondary hyperparathyroidism like the paricalcitol or the doxercalciferol which is chemically optimized to reduce PTH with the lower risk of hypocalcaemia. This indication requires further clinical trials on humans and renal insufficiencies with another criterion, the level of PTH in the blood. Hybrigenics Pharma is looking for contacts with pharmaceutical companies specialized in nephrology to successfully perform these studies in this other therapeutic domain. |