PaTHway CHINA TRIAL: A Trial to Investigating the Safety, Tolerability and Efficacy of TransCon PTH in Adults With Hypoparathyroidism

This study is limited to conduct in China only. The primary objective is to assess the treatment effect of daily TransCon PTH on serum calcium (sCa) levels within the normal range and stopping from therapeutic doses of active vitamin D (calcitriol) or active vitamin D analogue (alfacalcidol) and calcium at 26 weeks of treatment. All subjects will start with 18 mcg of study drug and will be individually and progressively titrated to an optimal dose over a 26-week double blind period, followed by an open label extension period up to 156 weeks. TransCon PTH or placebo will be administered as a subcutaneous injection using a pre-filled injection pen. Neither trial participants nor their doctors will know who has been assigned to each group. After the 26 weeks, participants will continue in the trial as part of a long-term extension study. During the extension, all participants will receive TransCon PTH, with the dose adjusted to their individual needs.