GSK advances programme for new osteoporosis therapies

A lead calcilytic compound being developed under licence by GlaxoSmithKline (GSK) has successfully completed a proof-of-concept trial and should be advanced into later stage studies.

GSK has been developing orally active, small molecule calcilytic compounds, which are targeted at bone and mineral disorders, such as osteoporosis. These compounds are the result of a 1993 collaborative research and licence agreement between NPS Pharmaceuticals and GSK.

Calcilytics work by antagonising calcium-sensing receptors on the surface of the parathyroid gland, thereby triggering a transient release of the body's own stores of parathyroid hormone (PTH). This release of PTH may have the potential to rebuild some of the bone mass lost as a result of osteoporosis and improve overall bone microarchitecture.

NPS and GSK have previously disclosed that, in animal models, daily oral administration of a calcilytic compound was shown to stimulate new bone formation, increase BMD at vertebral and non-vertebral skeletal sites, and increase biomechanical parameters of bone strength.

The proof of concept trial was a 28-day, multi-dose trial conducted in otherwise healthy, non-osteoporotic, post-menopausal women. Based on the results of this trial, GSK concluded that further clinical investigation is appropriate and is considering study options.

NPS, which is based in Salt Lake City and discovers, develops and commercialises small molecules and recombinant proteins as drugs , will receive royalties on global product sales and has the right to co-promote products resulting from the collaboration with GSK in North America.