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GEN News Highlights : Nov 7, 2011

NPS’ Parathyroid Hormone Replacement Therapy Succeeds in Phase III Trial

Orphan drug developer plans to file for FDA approval of NPSP558 during 2012.

NPS Pharmaceuticals reported positive topline data from a Phase III registrational trial evaluating the firm’s NPSP558, a bioengineered human parathyroid hormone replacement therapy (rhPTH 1-84), in adults with hypoparathyroidism. The firm says it now expects to file for NDA approval during 2012.

The NPSP558 trial data from this Replace trial was reported  just days after the firm annoulced positive results from a pivotal study with its lead candidate, Gattex (teduglutide) for short bowel syndrome, and plans to file for approval of this drug by year end.  

The 28-week, placebo-controlled NPSP558 study evaluated the drug in 134 patients. Data showed that in the intent-to-treat analysis, 53% of NPSP558-treated patients achieved the primary efficacy endpoint. This was defined as a 50% or greater reduction in oral calcium supplementation and active vitamin D therapy and a total serum calcium concentration that was normalized or maintained after 24 weeks of treatment when compared with baseline.

The results also showed that at week 24, 43% of patients treated with the parathyroid hormone replacement , but just 5% of placebo patients, were able to stop active vitamin D therapy and a calcium supplementation dose of 500 mg/day or less.

“Considering hypoparathyroidism is the only endocrine disorder for which we do not have an approved replacement hormone to treat the underlying condition, these data indicate that NPSP558 may offer a valuable option to achieve a physiological treatment and outcome by delivering the missing hormone,” remarks Bart Clark, M.D., an associate professor of medicine at the Mayo Clinic and one of the Replace study investigators. “Doctors currently can only provide supportive care aimed at managing the symptoms, and patients are faced with striking a balance between managing their symptoms and avoiding the long-term risks associated with current treatments, which can result in kidney stones, kidney damage, or even kidney failure.”