Amgen's Parsabiv has now been cleared for use in the US to treat secondary hyperparathyroidism (HPT) in adult patients with chronic kidney disease (CKD) on haemodialysis, after it was initially rejected by the US Food and Drug Administration in October last year.

sHPT is a common, serious and often progressive condition among patients with chronic kidney disease CKD, that develops in response to declining kidney function, when the parathyroid (PTH) glands increase the production of thyroid to maintain normal levels of calcium and phosphorus.

However, eventually this excess production is not enough to maintain normal levels, and at the point of CKD dialysis, this manifests as abnormal amounts of PTH, calcium and phosphorus that, in turn, can lead to significant clinical consequences, such as weakness and thinning of the bones.

Parsabiv (etelcalcetide) is a novel calcimimetic agent that suppresses the secretion of PTH by binding to and activating the calcium-sensing receptor on the parathyroid gland. The treatment is the first calcimimetic agent that can be given intravenously three times per week at the end of each dialysis session.

Phase III clinical data showed that 77 percent and 79 percent of patients given Parsabiv in two studies experienced a greater than 30 percent reduction from baseline in PTH compared with 11 percent in the placebo arms, and the drug fared better than Amgen's older sHPT therapy Sensipar (cinacalcet) on secondary endpoints of proportion of patients achieving greater than 30 percent and greater than 50 percent reduction in mean PTH.

Parsabiv is the first therapy approved for this condition in 12 years and the only calcimimetic that can be administered intravenously by the dialysis healthcare team three times a week at the end of the haemodialysis session, the firm noted.

"Parsabiv not only has demonstrated strong efficacy in clinical trials; it also fills an unmet need by putting the delivery of the therapy in the hands of the health care professional," commented Sean E Harper, executive vice president of Research and Development at Amgen.