The study is divided into two phases. In the first phase, participants will receive either PLS240 or a placebo to compare the effects. This phase is designed to see if PLS240 can effectively lower PTH levels by at least 30%. In the second phase, which is open-label, all participants will receive PLS240 to further assess its long-term safety. Participants will receive the medication through an intravenous injection, which means it will be administered directly into a vein using a pre-filled syringe.

The trial will last for a maximum of 53 weeks, during which participants will have regular check-ups to monitor their health and the effects of the treatment. These check-ups will include laboratory tests, physical exams, and monitoring of vital signs. The goal is to ensure the treatment is both effective and safe for individuals with secondary hyperparathyroidism undergoing hemodialysis.

The purpose of the study is to see how effective etelcalcetide is in lowering PTH levels in children aged 2 to 18 years who are undergoing hemodialysis. Participants in the study will receive etelcalcetide as a solution for injection. The study will follow a specific plan where the dose of the medication may be adjusted over time to find the most effective amount for each participant. The study will last for a period of up to 26 weeks, during which the participants will be closely monitored to assess the effects of the treatment.

Throughout the study, researchers will collect information on how the medication affects PTH levels, as well as other important factors like calcium and phosphorus levels in the blood. The safety of etelcalcetide will also be evaluated to ensure it is well-tolerated by the participants. This study aims to provide valuable information on the use of etelcalcetide in managing secondary hyperparathyroidism in young patients with chronic kidney disease.

The purpose of this research is to determine if alfacalcidol can help normalize hormone levels in patients who develop secondary hyperparathyroidism after weight loss surgery. The study will last for 24 months, during which participants will take the medication orally once daily. Throughout the study, doctors will monitor hormone levels and bone health to see how well the treatment works.

The research will also look at how the treatment affects bone density and overall quality of life. Bone density will be measured using special scans to check if there are any changes in the spine, hip, or arm bones. Participants will complete questionnaires about their quality of life every six months during the study period.

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.