Seventy-four percent of hemodialysis patients who received Amgen Inc.'s experimental drug AMG 416 (formerly known as velcalcetide) as part of a second phase 3 study experienced a drop in their parathyroid hormone levels of more than 30%, compared with 8.3% for patients who received a placebo. These results follow the announcement in July of positive data from a prior placebo-controlled Phase 3 study of AMG 416 which was similar in design and size.
The study also met its secondary endpoints, which included corrected calcium concentration and the percent change from baseline in serum phosphorus concentration. Both of these secondary endpoint results were statistically significant, the company reported.
AMG 416 is administered intravenously and binds to and activates the calcium-sensing receptor on the parathyroid gland, thereby causing decreases in PTH.
"The results from this second Phase 3 study help to confirm that AMG 416 could become an important new treatment option for dialysis patients with secondary hyperparathyroidism," said Sean E. Harper, MD, executive vice president of research and development at Amgen. "Despite the variety of options available for the treatment of this disease, an unmet need remains for an intravenous therapy that can be administered along with hemodialysis. We look forward to sharing results of a head-to-head study evaluating AMG 416 compared to cinacalcet next year."
Treatment-emergent adverse events (TEAEs) were reported in 91.6 and 78.7% of patients who received AMG 416 and placebo, respectively. TEAEs that were reported in greater than 10% of patients who received AMG 416 included blood calcium decrease (61% and 8.3%), nausea (12.4% and 5.1%), muscle spasms (12% and 7.1 %) and vomiting (10.4% and 7.1%). TEAEs of hypocalcemia (symptomatic) were reported in 7.2% of patients who received AMG 416 versus 0.4% in the placebo group. Serious adverse events (SAEs) were reported in 27.1% and 30.7%of patients who received AMG 416 and placebo, respectively
The study was a 26-week, randomized, double-blind, placebo-controlled study that evaluated the efficacy and safety of AMG 416 to treat secondary hyperparathyroidism in 508 patients with CKD receiving hemodialysis. Patients received AMG 416 or placebo three times per week by intravenous injection with each hemodialysis treatment. Doses ranged from a minimum of 2.5 mg to a maximum of 15 mg. Patients also received standard of care, which could include calcium supplements, vitamin D sterols and phosphate binders, if prescribed by the individual physician.