This clinical trial is focused on studying the effectiveness and safety of a treatment called PLS240 for individuals with secondary hyperparathyroidism, a condition that often occurs in people with end-stage kidney disease who are on hemodialysis. Secondary hyperparathyroidism is a disorder where the parathyroid glands in the neck produce too much hormone due to low calcium levels, often seen in patients with kidney disease. The treatment being tested, PLS240, is a solution for injection that contains the active substance upacicalcet sodium hydrate.

The purpose of this study is to evaluate how well PLS240 works in reducing the levels of a hormone called iPTH (intact parathyroid hormone) by at least 30% in participants undergoing regular hemodialysis. The study is divided into two phases: a double-blind phase, where neither the participants nor the researchers know who is receiving PLS240 or a placebo, and an open-label phase, where all participants receive PLS240. The double-blind phase will help determine the effectiveness of PLS240 compared to a placebo, while the open-label phase will focus on the long-term safety of the treatment.

Participants in the study will receive PLS240 through an intravenous bolus injection or IV infusion, which means the medication is delivered directly into the bloodstream. The study will last for a maximum of 53 weeks, during which participants will be closely monitored for changes in their iPTH levels and any potential side effects. The study aims to provide valuable information on the potential benefits and safety of PLS240 for managing secondary hyperparathyroidism in patients with end-stage kidney disease on hemodialysis.