A Study of PLS240 in Pediatric Participants With Secondary Hyperparathyroidism and Chronic Kidney Disease on Hemodialysis

Approximately 56 participants who are 1 month old to 17 years old will be enrolled in this study. The total duration for this study will be 38 weeks (or up to 42 weeks when participants require a washout period due to prior exposure to prohibited medications) and includes the following periods: * Active screening period of 6 weeks (or, up to 10 weeks for participants requiring a washout period). * Treatment period of 28 weeks consisting of a 19-week dose titration period and 9-week stable dose period. * Safety follow-up period of 4 weeks.