NPS Pharmaceuticals, Inc. (NASDAQ: NPSP), a biopharmaceutical company pioneering and delivering therapies that transform the lives of patients with rare diseases worldwide, today announced that its pivotal Phase 3 study of Natpara® (recombinant human parathyroid hormone (rhPTH[1-84]), known as REPLACE, was published online in The Lancet Diabetes & Endocrinology. Study findings underscore Natpara’s potential as a replacement therapy for endogenous parathyroid hormone (PTH) in hypoparathyroidism, a rare endocrine disorder characterized by insufficient production of PTH, a principal regulator of the body’s mineral homeostasis.
“Managing hypoparathyroidism can be challenging because it is limited to controlling symptoms, which does not address the underlying cause of the disorder and may have deleterious effects on major organs,” said Michael Mannstadt, MD, Massachusetts General Hospital and Harvard Medical School, and first author on the publication. “This is why we are encouraged by the findings from the REPLACE trial that confirm rhPTH (1-84) has the potential to be the first approved replacement therapy that addresses the underlying absence of parathyroid hormone, an approach long used in other classic endocrine disorders.”
When the body is missing PTH, blood calcium levels drop while phosphate levels increase, which can cause a number of physical and mental symptoms, including fatigue, muscle spasms and cramps, tingling, tetany, seizures, brain fog/mental lethargy, anxiety, and depression. Hypoparathyroidism is the only classic endocrine-deficiency disorder without an FDA-approved replacement therapy. It is currently managed with large doses of calcium and active vitamin D to maintain the calcium levels in the blood and reduce the severity of symptoms. Over time, calcium may build up in the body and result in irreversible calcifications in the kidneys, arteries or brain.
REPLACE, a 24-week international phase 3 study of efficacy and safety of daily subcutaneous Natpara in 134 patients with hypoparathyroidism, is the largest randomized, placebo-controlled clinical trial conducted to date in patients with this rare and complex endocrine disorder. Patients were randomized 2:1 to 50µg subcutaneous once daily Natpara or placebo. In the study active vitamin D and oral calcium were progressively reduced, while Natpara could be titrated up from 50 to 75 and then 100 µg. Patients self-administered treatment for 24 weeks and were then followed for four additional weeks after the completion of the treatment phase.