Amgen Submits NDA for Etelcalcetide Injection in China for Secondary Hyperparathyroidism in Dialysis Patients

On May 18, the Center for Drug Evaluation (CDE) of China's National Medical Products Administration announced that Amgen has submitted a New Drug Application (NDA) for etelcalcetide hydrochloride injection in China, which has been accepted by the CDE. Public information indicates that etelcalcetide (English brand name: Parsabiv) is a novel calcimimetic agent. It was approved in the United States in 2017 for the treatment of secondary hyperparathyroidism (SHPT) in adult patients with chronic kidney disease (CKD) on hemodialysis. This approval made etelcalcetide the first therapy approved for this disease in over a decade.

According to publicly available information, etecalcetide is a calcium-sensing receptor (CaSR) agonist that modulates CaSRs on the surface of parathyroid chief cells to regulate parathyroid hormone secretion, thereby reducing parathyroid hormone (PTH) levels. In patients with secondary hyperparathyroidism, declining renal function and impaired mineral metabolism trigger excessive PTH secretion by the parathyroid glands, leading to substantial loss of calcium and phosphate from bone tissue. Studies have demonstrated that intravenous infusion of etecalcetide at the end of hemodialysis sessions effectively reduces PTH levels, corrects calcium and phosphate levels, and maintains therapeutic efficacy for up to 78 weeks.

In February 2017, the FDA approved etelcalcetide for the treatment of secondary hyperparathyroidism in adults with chronic kidney disease (CKD) on dialysis. According to a press release issued by Amgen at the time, etelcalcetide was the first therapy approved in 12 years for this condition, and the only intravenous calcimimetic administered three times weekly by dialysis healthcare personnel at the end of a hemodialysis session.

This FDA approval was primarily based on the results of two placebo-controlled Phase 3 trials, which enrolled a total of 1,023 patients with moderate to severe SHPT. The trials compared the efficacy of intravenous etelcalcetide administered following dialysis in reducing serum PTH levels. Both trials met their primary endpoints, with a significantly higher proportion of patients achieving a >30% reduction from baseline PTH during the efficacy assessment period (EAP, weeks 20 to 27) (77% vs. 11% in Study 1; 79% vs. 11% in Study 2). Regarding secondary endpoints, the proportion of patients with PTH levels ≤300 pg/mL during the EAP was also significantly increased (52% vs. 6% in Study 1; 56% vs. 5% in Study 2).

Furthermore, in a pooled analysis of two studies, the incidence of asymptomatic hypocalcemia and symptomatic hypocalcemia was higher in patients treated with etelcalcetide compared with placebo (64% vs. 10% and 7% vs. 0.2%, respectively). Other common adverse reactions included muscle spasms, diarrhea, nausea, vomiting, and headache.